The most common symptoms of COVID-19 infection, to include in pregnant women, include fever, cough, and shortness of breath.
The Bottom Line

*NEW July 13: "COVID-19 Antibody Transfer to Fetus/Newborn" section added

According to currently available case series and cohorts as of July 2021, data indicates pregnant women are not more susceptible to contracting COVID-19 than non-pregnant women, and fetal and symptomatic neonatal infection appear to be rare events.

However, pregnant women who contract COVID-19 appear to be at higher risk of certain complications from the disease than non-pregnant women of reproductive age. These complications include Intensive Care Unit admission, mechanical ventilation, and the need for extracorporeal membrane oxygenation (ECMO), as well as the risk of death (although overall risk remains low).

Research indicates pregnant women can experience a complete lack of symptoms (asymptomatic) to a wide range of acute and long-lasting symptoms, similar to the general population. These include fever, shortness of breath, cough, nausea, congestion, runny nose, vomiting, diarrhea, chills, loss of smell, sore throat, headaches, body aches, and excessive phlegm.

Therefore, pregnancy remains a risk factor for possible severe infection. Any pregnant woman experiencing one or more of the above symptoms should call her health care provider (HCP) for an evaluation.

Women also need to report to their HCP any exposure they have had to an individual with confirmed or suspected COVID-19. As pregnant women can experience asymptomatic infection, some HCPs may recommend these women be tested, especially women with certain underlying conditions (obesity, diabetes, hypertension, asthma).

Women should ask their HCP any questions or concerns they have regarding COVID-19 or its vaccines and visit the CDC website for more information.

*If you are experiencing trouble breathing or extreme shortness of breath, seek emergency medical care immediately or dial 911*

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Most Recent Updates

July 23, 2021: As of July 10 (although data collection is limited), the COVID-19 case count among pregnant women in the U.S. is at its lowest point since February 29, 2020.

Cases of COVID-19 among Pregnant Women by Week of Diagnosis (data were collected from 101,710 women):

CDC. "Data on COVID-19 during Pregnancy: Severity of Maternal Illness" 10 July 2021. https://covid.cdc.gov/covid-data-tracker/#pregnant-population. Accessed July 23, 2021.

July 19, 2021: As of 19 July, 136,543 pregnant women have received a COVID-19 vaccination during pregnancy. Of these, 5,103 are being watched closely via the CDC's v-safe pregnancy registry.

June 30, 2021: The UK's Royal College of Obstetricians and Gynaecologists (RCOG) published new COVID-19 vaccination guidance during pregnancy and breastfeeding:

According to the guidance, "as of 7 June 2021, over 120,000 pregnant women from diverse ethnic backgrounds in the USA have received either a Pfizer-BioNTech or Moderna COVID-19 vaccine, with no evidence of harm being identified.9 In general, there are no known risks from giving inactivated or recombinant vaccines in pregnancy, or while breastfeeding,10 and there is therefore no reason to suppose that the adverse effects from these COVID-19 vaccines should be different for pregnant women compared to non-pregnant women."

The rare syndrome of vaccine-induced thrombosis and thrombocytopenia (VITT) has been reported after the Oxford-AstraZeneca vaccine; it has also been reported after the Janssen vaccine...It has been described as presenting 5–28 days after the first dose, particularly in adults younger than 50 years old. Although pregnancy increases the risk of coagulopathy there is no evidence that pregnant or postpartum women are at higher risk of VITT than non-pregnant women."

Read the full guidance here.

updated

Overall Key Findings (as of 13 July)

Infection

  • Pregnant women do not appear to be at an increased risk of infection from COVID-19 over non-pregnant women (i.e. same infection rate).

  • However, pregnant women appear to have an increased risk of intensive care unit (ICU) admission, mechanical ventilation, and extracorporeal membrane oxygenation (ECMO), as well as death (but overall risk is low).

  • Rates of pneumonia and preterm delivery may also be increased compared to pregnant women without infection, but these results are inconsistent.

  • There is a significant racial disparity; pregnant Hispanic and non-Hispanic Black women experience even higher risks of complications from COVID-19 infection.

  • Regarding fetal and neonatal health, current results are reassuring and indicate newborns of mothers who contract COVID-19 appear to be born healthy.

  • Current evidence also indicates the virus does not readily cross the placenta or infect the fetus. Although there are case reports of this occurring, the event appears to be rare and likely depends on severity of infection.

  • Preliminary research indicates COVID-19 infection in early pregnancy does not appear to increase the risk of miscarriage, but more research is necessary.

  • Infant infection from exposure to an infected parent or caregiver likely accounts for most infections reported in newborns; majority of these infections appear to be asymptomatic or mild.

  • There is currently no evidence that COVID-19 infection can be transferred to the baby through breast milk; breast milk of previously infected mothers appears to contain COVID-19 antibodies (no reason to separate mother and baby after delivery).

  • There is currently no long-term data on how COVID-19 infection during pregnancy could affect women or their babies.

Weekly COVID-19 Pregnancy Data from CDC:

  • Total Cases: 101,710

  • Hospitalized: 17,380 (data only available for 81,138)

  • Total Deaths: 114

*As of July 23, 2021

These numbers likely do not include all pregnant women with COVID-19 in the United States and must be interpreted with caution.

Vaccination

  • Pregnant and breastfeeding women may choose to be vaccinated when eligible and should have a risks and benefits discussion with their health care provider.

  • As of June 2021, more than 120,000 pregnant women have been vaccinated in the U.S. Side effects of vaccines in pregnant women are similar to those expected among the non-pregnant population. Side effects are generally short-lived; no adverse effects to fetuses have been identified. Fever following vaccination can be treated with acetaminophen to decrease adverse-fever associations risks (talk with health care provider).

  • Recent reports show that people who received mRNA COVID-19 vaccines during pregnancy and/or while breastfeeding have passed antibodies to their fetuses. These antibodies could help protect babies, but more information is necessary to determine effectiveness of these antibodies and how long they may last.

  • There is currently no evidence COVID-19 vaccines have any adverse impact on fertility based on mechanism of action (read more below).

  • There is currently no evidence or mechanism of action in which vaccinated individuals "shed" and/or could cause infertility in other individuals by simply being around them. There is no scientific basis for this as the COVID-19 mRNA vaccines do not replicate and they are not live-attenuated (not a live virus).

  • Fully vaccinated individuals have low risk of passing infection, including to a newborn. Based on May 13 CDC guidelines, individuals do not need to wear a mask when meeting a baby unless they want to [or at parent request]; talk to pediatrician with any concerns.

Background

In December 2019, health officials in China indicated they had a serious outbreak of a respiratory illness caused by a new type of coronavirus, COVID-19, or “coronavirus disease 2019”.

In February 2020, the virus was given the specific name “severe acute respiratory syndrome coronavirus 2” or SARS-CoV-2. In March 2020, the World Health Organization (WHO) officially declared the outbreak a worldwide pandemic.

This page will refer to SARS-CoV-2 as COVID-19.

Various coronavirus infections during pregnancy – such as severe acute respiratory syndrome (SARS) and Middle-East respiratory syndrome (MERS) – have been associated with a higher incidence of severe illness in the mother and adverse outcomes for the fetus.

Fortunately, current evidence indicates that COVID-19 is significantly less lethal than SARS and MERS and pregnant women may only have a slightly higher risk of certain complications over non-pregnant individuals. However, there is still very little data regarding pregnancy-related outcomes and COVID-19.

Coronaviruses – General

The term coronavirus derives from the Latin word corona, which means crown or halo. Under electron microscopy, the virus particles display a crown-like pattern on its outside, similar to spikes, which has resulted in the very common computer-generated image of the virus below. In general, coronaviruses cause illnesses ranging from asymptomatic infection to fatal infection.

CDC graphic.

There are seven coronaviruses currently infecting humans. COVID-19 is the third coronavirus to cause a major epidemic, after SARS and MERS. However, COVID-19 has infected a far greater number of people than SARS and MERS combined.

Information on the effects of SARS and MERS during pregnancy was being used early in the pandemic to help manage pregnant women with COVID-19. However, more current data has shown several differences between SARS, MERS, and COVID-19, with data indicated COVID-19 is far less lethal in pregnant women compared to SARS and MERS.

SARS spread to nearly 30 countries around the world resulting in more than 8,000 cases and 770 deaths. Public health control measures were highly effective at stopping the spread of the disease, and no cases been reported since 2004.

Symptoms of SARS consisted of fever, chills, headache, general discomfort, muscle pain, and diarrhea, with an incubation period of around 4.6 days, but a range of 2 to 14 days. Almost all patients contracted pneumonia. Case fatality rate was estimated at 9% to 10%.

However, the case fatality rate for pregnant women with SARS was estimated at 25%; pregnant women were more likely to develop kidney failure, sepsis, and blood clots throughout the body.

Fortunately, there was no evidence of the virus being transmitted to the fetus if the mother contracted the infection during pregnancy. However, case series of pregnant women infected with SARS were extremely limited.

MERS was first identified in Saudi Arabia in 2012; nearly 2,500 cases were confirmed which resulted in approximately 860 deaths.

Commonly seen symptoms included fever, cough, shortness of breath, and sometimes diarrhea, with an incubation period of around 5.2 days, but a range of 2 to 13 days. The case fatality rate was estimated to be very high, at 35% to 40%.

There is not much data regarding MERS during pregnancy. Seven of 13 patients identified in at least one review were admitted to an intensive care unit for respiratory deterioration and three died.

SARS-CoV-2 (COVID-19)

Sequencing data show that COVID-19 has a 79% genetic similarity to SARS and about 50% to MERS. However, as of July 5, 2021, COVID‐19 has an overall significantly lower fatality rate, estimated around 1.8% in the United States (2.6% in the UK, 1.8% in Canada, and 3.0% in Australia). Pregnant women appear to have the same fatality rate as non-pregnant women.

Human-to-human transmission occurs through close contact via respiratory droplets; incubation time averages 4 to 5 days but can range from 1 to 14 days. It is estimated almost all infected individuals develop symptoms by 11.5 days.

Infected droplets can also spread to distances of up to 6 feet and deposit on surfaces (fomites). These fomites can then infect healthy individuals who touch the unsanitized surface and then touch their mouth, nose, or eyes.

COVID-19 infection can be described in 3 stages:

  • Stage 1: Incubation period; may include asymptomatic infection

  • Stage 2: The virus is detectable and presents with minor or mild symptoms such as a fever

  • Stage 3: Severe symptoms arise which may require hospitalization and could result in respiratory distress or death

Individuals can experience a complete lack of symptoms to a wide range of acute and long-lasting symptoms. These include fever, shortness of breath, cough, nausea, congestion, runny nose, vomiting, diarrhea, chills, loss of smell, sore throat, headaches, body aches, excessive phlegm, coughing up blood, pneumonia, and blood clotting issues.

Studies of hospitalized patients with COVID-19 indicate that severe pneumonia is common and approximately 17% to 29% of these cases progress to acute respiratory distress syndrome. It is currently estimated that once hospitalized, these patients may have a 4% to 15% fatality rate.

Pregnancy-Specific Data

Researchers are attempting to determine pregnant women’s susceptibility to COVID-19 infection, the possibility of fetal infection (vertical transmission), severity of symptoms, potential complications, resulting outcomes, and the health of infants born to infected mothers.

Pregnant women experience the same symptoms as the general population, and may even be largely asymptomatic. Symptoms include shortness of breath, fever, fatigue, chills, muscle aches, and cough. Infection appears to significantly more common in the third trimester, but this may be due to universal testing as women are admitted for labor and delivery.

Further, a study published in April 2021 indicated that based on preliminary results, earlier gestation pregnancies (first, second trimesters) may be more vulnerable to infection than later gestation pregnancies.

April 22, 2021: According to a large-scale, prospective, multinational study, women with COVID-19 diagnosis, compared with those without COVID-19 diagnosis, "were at substantially increased risk of severe pregnancy complications, including preeclampsia/eclampsia/HELLP syndrome, ICU admission or referral to higher level of care, and infections requiring antibiotics, as well as preterm birth and low birth weight. The risk of maternal mortality was 1.6%, i.e, 22 times higher in the group of women with COVID-19 diagnosis."

"These deaths were concentrated in institutions from less developed regions, implying that when comprehensive ICU services are not fully available, COVID-19 in pregnancy can be lethal. Reassuringly, we also found that asymptomatic women with COVID-19 diagnosis had similar outcomes to women without COVID-19 diagnosis, except for preeclampsia."

According to a March 2021 report from the U.K. Government regarding 5,479 hospitalized COVID-19 positive pregnant women:

  • Overall, these women had good outcomes (likely due to low threshold for admittance)

  • 10% received critical care

  • 1% died (may have been result of women delaying care)

  • 18% had a preterm birth (about 2.5 times the background rate)

The report also noted that pregnant women hospitalized in areas/periods since the B117 variant became predominant were more likely to require respiratory support.

Although most studies to date have indicated pregnant women are not more susceptible to infection than the non-pregnant population, a February 2021 study determined the COVID-19 infection rate in pregnant women in Washington State was 70% higher than similarly aged adults, which could not be completely explained by universal screening at delivery.

Overall, while symptoms remain relatively similar to non-pregnant individuals, pregnant women with COVID-19 do also appear to have an increased risk of hospitalization, ICU admission, mechanical ventilation, and the use of ECMO, as well as death, especially in the third trimester. However, overall risk remains low.

Despite this increased risk, these events still do not appear to be common. A November 19 study of 252 pregnant women who tested positive for COVID-19 indicated that approximately 5% of all pregnant women with COVID-19 infection develop severe or critical illness. Further, according to the Society for Maternal Fetal Medicine as of November 23, overall low absolute risks appear to be: 2.9 per 1,000 for invasive ventilation, 0.7 per 1,000 for ECMO, and 1.5 per 1,000 for death.

COVID-19 and miscarriage risk is unknown. Preliminary research has not shown a link, but more data is necessary.

At least two studies assessing whether COVID-19 had any impact on early pregnancy loss determined the infection appears to have a favorable maternal course at the beginning of pregnancy and does not appear to increase the risk of miscarriage (Cosma et al. 2020; Rotshenker-Olshinka et al. 2020) 

However, at least two separate studies from August/September 2020 identified COVID-19 receptors in the early oocyte and blastocyst; therefore, it is possible that infection in early pregnancy could have adverse effects on the embryo. Significantly more research is necessary in larger populations of women (Weatherbee et al., 2020; Essahib et al. 2020).

First case report of this nature: A case study published in March 2021 found COVID-19 nucleocapsid protein, viral RNA, and particles in the placenta and fetal tissues of an early pregnancy miscarriage from a pregnant woman who had tested positive for the infection. The study also determined that fetal organs, such as lung and kidney may be targets for coronavirus (Valdespino‐Vázquez et al. 2021).

Pre-existing conditions likely play a role in disease severity, such as obesity, older maternal age, hypertension, diabetes, and asthma. Black and Hispanic pregnant women also appear more likely to experience severe infection and hospitalization.

Of note, and regardless of severity, pregnant women may experience a longer duration of symptoms, as at least one study indicated some COVID-19 positive pregnant women experienced symptoms eight weeks or longer after diagnosis (but many others have no symptoms).

Further, a study pre-published on November 16 provided preliminary evidence that pregnant women exhibit a reduced antiviral antibody response against COVID-19. This could impact the effectiveness of certain antiviral treatments and increase the potential for reinfection following pregnancy.

Risk of preterm delivery is very inconsistent; while some reports have documented an increased risk of preterm birth, others have not find an association. However, this inconsistency may be due to a lack of clarity regarding why preterm delivery was indicated (i.e. not necessarily due to COVID-19 complications).

In some reports, cesarean section was performed to improve the mother’s condition, the baby’s condition, or was triggered for other reasons that may not have been related to infection.

A 34 week premature baby in an isolette incubator with oxygen (not due to COVID-19).

According to a November 2020 CDC report, among 3,912 infants born to women with COVID-19, 12.9% were preterm, which is higher than the national estimate of 10.2%. Among 610 of those infants with testing results, 16 were positive for COVID-19, primarily those born to women with infection at delivery. Eight of those 16 infants were born preterm.

There is also informal and anecdotal reporting of a lack of preterm deliveries overall during the pandemic. This phenomenon could be due to women resting more, staying at home, having more familial support, or lack of infections in general, not just COVID-19 (infection is a primary cause of preterm birth). There may also be a decrease in preterm induction, usually indicated by HCPs for medical reasons.

Therefore, although pregnant women – overall – have a low risk of severe infection with COVID-19, pregnancy remains a risk factor for complications as study sizes are mostly small, not all maternal outcomes are indicated, and results remain inconsistent. Additionally, there is almost no data regarding COVID-19 and pregnancy-related outcomes when women are infected early in pregnancy.

COVID-19 viral shedding may last longer in pregnant women.

A case report published in July 2020 indicated that a pregnant woman who tested positive at 28 weeks of pregnancy still tested positive at 38 weeks, and did not test negative until almost 50 days after delivery. The newborn, as well as placenta, cord blood, meconium, and breast milk samples were all negative for the virus. The cord blood was positive for antibodies.

The authors of the study assessed that pregnancy may cause slower clearance of the virus. However, this does not mean the virus is contagious (or active) during this time frame (Molina, et al. 2020).

Additional Considerations

Up to 70% of pregnant women already experience pregnancy-related shortness of breath, especially in the third trimester. This symptom could be made significantly worse with COVID-19 infection.

Additionally, physiological changes in pregnant women’s immune, cardiovascular, and respiratory systems can render them more vulnerable to complications relating to a lack of oxygen (it is harder to compensate).

Stage of pregnancy may also play a role in COVID-19 disease severity, similar to influenza, although data is limited. COVID-19 is a pro-inflammatory virus that causes severe and excessive inflammation throughout the entire body. Early pregnancy and near term (third trimester) are considered pro-inflammatory, which could make COVID-19 infection more severe at these stages, but more research is necessary.

Infection Transmission to Fetus/Newborn

In general, vertical transmission of any virus from the mother to fetus is not well understood, but can occur through amniotic fluid, placenta, umbilical cord blood, or vaginal delivery.

Note: Maternal and fetal blood never directly mix during pregnancy; this exchange takes place in the placenta.

As of July 2021, it does not appear that COVID-19 readily crosses the placenta, enters amniotic fluid or umbilical cord blood, or transfers to the newborn via vaginal delivery (which does occur with other viruses). Further, neonates born to mothers who tested positive for COVID-19 appear to remain relatively healthy (and may receive their mother's COVID-19 antibodies).

However, neonates have tested positive for the virus within 30 minutes of delivery, and the virus has been identified in placental tissue and amniotic fluid in a small number of cases. But overall, this appears to be very rare and likely depends on severity of infection, stage of pregnancy, and how long the fetus is exposed to the virus (i.e. time of infection in the mother to time of delivery).

In a study of 86 neonates who were tested for the possibility of vertical transmission, only three were positive. Interestingly, one neonate was negative at the time of delivery but tested positive 24 hours later. This neonate also had amniotic fluid and cord blood tested; amniotic fluid was positive, but the cord blood was negative.

One study examined sixteen placentas from COVID-19 infected women. Third trimester placentas were more likely to reflect a systemic inflammatory or hypercoagulable state (tendency for blood to clot). Despite these changes, all neonates tested negative for the virus and were discharged within four days.

However, a separate study that examined twenty-one third trimester placentas of women who tested positive for COVID-19 did not find any major adverse effects on placental structure and pathology, and another study from December 2020 identified no placental or fetal transfer of the virus.

Additional evidence of vertical transmission has been found with several neonates testing positive for antibodies; these antibodies can be passed from mother to fetus (IgG), or the fetus can make its own antibodies (IgM) after being infected (more research is necessary).

Infected pregnant women appear to pass COVID-19 antibodies to their newborns.

A study published in May 2021 determined that maternal COVID-19 infection results in efficient transfer of maternal antibodies across the placenta when infections occur more than two months before delivery. Further, these antibodies may protect the infant up to six months of life (Song et al. 2021).

A study published in June 2021 determined that a shorter interval between maternal symptoms and delivery is an influencing factor that may increase the likelihood of vertical transmission.

The timing in which fetuses may be infected in utero is not known or understood. While some reports indicate there is no evidence of vertical transmission of COVID-19 when the infection occurs during the third trimester, this may only be because delivery occurs so shortly thereafter.

Two stillbirths have been documented from severe infection, one in the second trimester and one in the third trimester, indicating possible transmission (no additional information was available). Further, at least one fetal demise has been identified in a woman who contracted COVID-19 in the first trimester.

Note: Overall, data regarding risk of stillbirth and COVID-19 are inconsistent, but it does appear to be rare. While some reports have indicated a slight increased risk, others have not found an association. Further, in at least one study that indicated an increased risk, this increase was thought to be due to factors other than COVID-19 infection (more in Prenatal Care/Appointments).

Therefore, it is likely (rare) vertical transmission could happen during any trimester but additional research and clarification between COVID-19 positive newborns and timing of infection in the mother is necessary.

There is currently a lack of evidence the virus can be transmitted through breastmilk.

It is very unlikely COVID-19 infection can be passed from mother to baby via breastmilk. Further, breastmilk from infected mothers was found to contain COVID-19 antibodies and neutralized COVID-19 activity.

However, for currently infected mothers who wish to breastfeed, it is still possible to transmit the infection when the neonate is in close contact. Therefore, it is advised women should consider wearing a face mask during feedings or using a breast pump until they test negative (Pace et al., 2021; Zhu et al., 2021; WHO, June 2020; Dong et al. 2020).

Regarding the postpartum period, recommendations vary. However, according to a U.K. study of 66 newborns who tested positive for COVID-19, two newborns were suspected of contracting the infection during pregnancy, while 17 were suspected of contracting the infection from their mother after delivery.

The authors indicated that despite these numbers, the newborns did not experience severe illness, and the benefits of remaining with the mother after delivery appear to outweigh the possibility of infection. Symptoms in these newborns included high temperature, poor feeding, vomiting, a runny nose, cough and lethargy.

Testing

The most used test for COVID-19 is the RT-PCR (real time reverse transcription-polymerase chain reaction). This type of test is used to identify the genetic material of a virus (see Resources). Specimens are collected from the patient’s nose or throat using nasopharyngeal or oropharyngeal swabs.

It is often recommended that if the first test is negative, but the disease is highly suspected, a second test should be performed. A negative result can be confirmed through two negative tests in a row, spaced at least 24 hours apart. Researchers do not yet know the most optimal timing to administer the test (especially in newborns).

HCPs may also use a chest CT scan for COVID-19 diagnosis, as this has been reported to be superior in early diagnosis compared with RT-PCR. The CT can show what is called “ground glass”, or white spots on the lungs that indicate the infection is present. For pregnant women, the diagnostic value of the CT may outweigh possible radiation risk to the fetus (read Radiation).

Women should have a risks and benefits conversation with their HCP regarding any imaging scans during pregnancy.

Some health care facilities may universally test all pregnant women prior to delivery, as pregnant women can also be asymptomatic, similar to non-pregnant individuals.

Management and Treatment

The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) have developed an algorithm to aid practitioners in assessing and managing pregnant women with suspected or confirmed COVID-19 (read more).

Overall treatment plan: There is no definitive treatment regimen for pregnant women with COVID-19; therefore, all management is currently individualized based on disease severity, stage of pregnancy, and risks and benefits of any medications.

It is also recommended that every pregnant woman with COVID-19 should be monitored carefully due to possible complications, even if a woman initially presents without symptoms.

Formally, and depending on severity, recommendations include isolation, infection control procedures, diagnostic testing, oxygen therapy if needed, antibiotics (secondary bacterial infection risk), fetal and uterine contraction monitoring, and an individualized delivery plan.

Antiviral Medication: Currently, there is no specific drug for COVID-19; further, if a drug does appear to be safe and effective in the non-pregnant population, there is likely no scientific data to guide its use during pregnancy.

Medications such as Type I interferon, lopinavir, ritonavir, and tocilizumab are still being studied in the general population and are not (routinely) recommended for pregnant women; studies on safe and effective treatments for COVID-19 positive pregnant women are ongoing.

Pregnant women were routinely excluded from early COVID-19 clinical trials.

As of April 2020, only 1.7% of COVID-19 trials included pregnant women, and only three involved an intervention or medication (Smith et al., May 2020).

As of July 2021, numerous clinical trials are underway regarding COVID-19 infection and pregnancy, treatment methods, and newborn outcomes, as well as the safety and effectiveness of vaccination.

Remdesivir is also not routinely recommended for pregnant women due to a lack of safety data as well as effectiveness. However, it may be used in severe cases under compassionate use and has been linked with initial positive results (very small case studies). Side effects of remdesivir in pregnant woman may include possible liver complications.

Blood clotting: Both pregnancy and COVID-19 are associated with an increased risk for blood clotting – to include in asymptomatic women in isolation at home. However, this is also slightly debated as not all studies have found an increased risk. Further, although case reports exists, widespread reporting of blood clotting issues from COVID-19 infection in pregnancy has not been reported.

Some guidance indicates that suspected and confirmed COVID-19 pregnant women should receive preventative low-molecular-weight heparin (LMWH) before and after delivery (unfractionated heparin if delivery is close). Other reviews indicate there is not enough evidence to recommend heparin, and this medication could increase the risk of bleeding.

Delivery: Since there is currently no evidence that vaginal delivery can increase the risk of vertical transmission, mode of delivery should also be individualized and depends on stage of pregnancy, health of the fetus, and the mother’s overall health.

Fetus/Newborn: Prior to delivery, it is recommended that women undergo regular fetal heart monitoring and ultrasounds to monitor growth. Steroids may be considered for fetal lung maturation, depending on gestational age and severity of the mother’s disease.

After delivery, guidelines also conflict on whether the newborn should be separated from the (infected) mother to prevent infection transmission. However, most obstetric organizations agree the benefits of the mother and baby being together outweigh the possible risks of transmission. Women and their HCPs should have individualized discussions regarding infant separation for mothers suspected or confirmed to have COVID-19.

Photo by engin akyurt on Unsplash
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Antibody Transfer to Fetus/Newborn

Current data on COVID-19 antibody transfer to the fetus/newborn after maternal infection during pregnancy:

  • All types of infections – asymptomatic, mild, severe –initiate antibody transfer across the placenta.

  • Antibody levels from mild COVID-19 infection during pregnancy appear to decline more quickly than after severe infection (may be faster decline for asymptomatic, but this was not studied).

  • A longer interval between infection and delivery provides more time for effective transplacental transfer of antibodies (e.g. two months better than two weeks; also likely depends on severity of infection).

  • However, infection in early pregnancy may not provide lasting antibody protection to fetus/newborn (vs. infection in late pregnancy) as this interval could be too long.

  • Antibody levels passed to a newborn after COVID-19 infection during pregnancy have been shown to decline in infants approximately 6 to 11 weeks after birth.

  • Despite this decline, passive immunity may persist in infants up to six months of life.

  • Infection in early to mid-pregnancy + vaccination later in pregnancy appears to be safe and produces strong antibody transfer across the placenta (and is recommended).

  • COVID-19 infection during pregnancy also transfers antibodies to colostrum and breastmilk; these antibodies are effective at neutralizing the virus.

  • However, it is currently unclear how long this lasts; likely depends on stage of pregnancy during infection, severity of infection, whether infant is exclusively breastfed, and length of time the infant is breastfed.

Prenatal Care/Appointments

Women who attend their prenatal appointments should be assessed for fever each time and evaluated for signs and symptoms of a respiratory infection.

Women need to express any concerns they have with their HCP, to include their appointment schedule (virtual or in person), fetal monitoring, what they should do in-between appointments if they suspect infection, and what to do if they experience contractions, especially if nearby hospitals have changed their procedures.

Pregnant women should not be afraid to seek medical care, including emergency care, during the pandemic.

Reporting indicates that some pregnant women may avoid certain HCP appointments or even possible emergency department visits out of fear of being infected with COVID-19.

However, this can be incredibly dangerous during pregnancy, especially if bleeding and/or abdominal pain is present (i.e. ectopic pregnancy, placental complications). Women with these symptoms, or any indication in which they believe they need medical care, should visit their HCP/emergency department immediately (Comeau, CMAJ 2 July).

Further, if women are nervous about in-person appointments, they can talk to their HCP about the possibility of virtual visits, in otherwise healthy, uncomplicated pregnancies.

Women should continue to see their HCP when recommended, or when they feel they may be experiencing a concern.

At least one study noted an increase in the stillbirth rate in one U.K. hospital during the pandemic. Of note, none of the stillbirths were indicated in women who tested positive for COVID-19. This indicates that a decrease in appointments, prenatal care, routine screenings, or ultrasounds may have occurred that led to this increase.

Women also need to tell their HCP how they are coping with the pandemic. Increasing isolation, preventative measures, anxiety about their health and the health of their baby, and a significant amount of uncertainty can increase women’s risk for depression and anxiety during pregnancy and the postpartum period.

Latest Organizational Recommendations

April 2021 (from CDC):  CDC and FDA have recommended that use of Johnson & Johnson’s Janssen (J&J/Janssen) COVID-19 Vaccine resume in the United States, effective April 23, 2021. However, women younger than 50 years old should be aware of the rare risk of blood clots with low platelets after vaccination, and that other COVID-19 vaccines are available where this risk has not been seen. Read the CDC/FDA statement.

Obstetric organizational guidance:

April 12, 2021: The U.K.'s Royal College of Obstetricians and Gynaecologists, "Trials testing the vaccine in pregnant and breastfeeding women have not yet taken place. Whether to get the vaccine in pregnancy is your choice...There is still very little evidence for pregnant women, but the information that we do have does not show any safety concerns or harm to pregnancy from the COVID-19 vaccine. More information may come from studies in the future."

Photo by CDC on Unsplash

April 1, 2021 (originally published on December 15, 2020): The Society for Maternal Fetal Medicine (SMFM) released a report stating: "Vaccination is available during pregnancy. Counseling should balance available data on vaccine safety with the lack of data related to fetal risk, the pregnant person’s risk for SAR-CoV-2 acquisition, and their individual risk for moderate or severe disease. The level of COVID-19 community transmission should also be considered in counseling for vaccination."

  • "Data from both v-safe and VAERS [more details in next section] have not shown any patterns to indicate safety problems with the Pfizer and Moderna COVID vaccines in pregnant people, and no unexpected pregnancy or infant outcomes have been reported. Safety monitoring in pregnant people is ongoing, and the Janssen Biotech vaccine will be included in future vaccine safety surveillance activities."

March 24, 2021 (originally published on December 13, 2020): ACOG released a statement indicating that for pregnant individuals, the decision to vaccinate must be left to each patient in consult with their trusted clinician, and that "vaccines should not be withheld from pregnant individuals who meet criteria for vaccination based on CDC's Advisory Committee on Immunization Practices-recommended priority groups". ACOG also added:

  • Pregnancy testing should not be a requirement prior to receiving any EUA-approved COVID-19 vaccine.

  • Unfounded claims linking COVID-19 vaccines to infertility have been scientifically disproven. ACOG recommends vaccination for all eligible people who may consider future pregnancy.

  • Pregnant patients who decline vaccination should be supported in their decision.

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Vaccine Safety & Effectiveness Data in Pregnancy (Breastfeeding Section Below)

May 25, 2021: Among fifteen women who received at least one dose of Pfizer (including five breast-feeding women and two women vaccinated in early pregnancy), none had placental anti-syncytin-1 binding antibodies at either time-point following vaccination. This means the vaccine did not cause antibodies toward a placental protein, adding further evidence to its safety in pregnancy. The study also determined that mRNA was not detected in breastmilk.

May 24, 2021: Additional information from CDC partner call:

  • As of May 17, 2021, over 114,000 pregnant women have received a COVID-19 vaccination and been entered into v-safe; current data indicates rates of adverse outcomes are similar to rates in the same number of pregnant women prior to the pandemic.

  • There is currently no data yet to determine if vaccinated pregnant women are experiencing breakthrough infections, but CDC is actively monitoring this possibility.

  • With vaccine rollout starting in December 2020, we are only 24 weeks into distribution and we are just starting to see outcomes of women vaccinated in their 1st trimester; getting additional data out as soon as they can is a priority.

  • Limited information on whether there is an "ideal" time to be vaccinated during pregnancy, but pregnant women should get vaccinated when they can. Recommendations will evolve overtime; women should talk to their health care provider with questions about their individual risks.

May 20, 2021: New study that assessed antibodies in babies after the mother was COVID-19 vaccinated during pregnancy shows evidence the vaccine itself does not cross the placenta, only the mother's antibodies (IgG). If the vaccine had crossed the placenta, researchers should have seen IgM antibodies, but none of the infants from vaccinated mothers had this type of antibody.

May 18, 2021: According to a Mayo Clinic report, vaccinated pregnant women in this birth cohort (2,002 patients; 140 received vaccination during pregnancy and 212 experienced a COVID-19 infection) were less likely to experience COVID-19 infection compared to unvaccinated pregnant patients, and COVID-19 vaccination during pregnancy was not associated with increased pregnancy or delivery complications.

May 13, 2021: In this cohort study involving 103 women who received a COVID-19 mRNA vaccine, 30 of whom were pregnant and 16 of whom were lactating, immunogenicity was demonstrated in all, and vaccine-elicited antibodies were found in infant cord blood and breast milk. Further, pregnant and nonpregnant vaccinated women developed cross-reactive immune responses against SARS-CoV-2 variants of concern.

May 11, 2021: Study found no evidence that mRNA COVID-19 vaccination during pregnancy harms the placenta (84 vaccinated individuals, 116 controls). "Placental examination in women with vaccination showed no increased incidence of decidual arteriopathy, fetal vascular malperfusion, low-grade chronic villitis, or chronic histiocytic intervillositis compared with women in the control group. Incidence of high-grade chronic villitis was higher in the control group than in the vaccinated group."

April 21, 2021: From December 14, 2020, to February 28, 2021, researchers used data from the “v-safe after vaccination health checker” surveillance system, the v-safe pregnancy registry, and the Vaccine Adverse Event Reporting System (VAERS) to characterize the initial safety of mRNA Covid-19 vaccines in pregnant persons:

A total of 35,691 pregnant women were passively followed in the v-safe registry. Injection pain was noted to be higher among pregnant women, while headache, muscle pain, chills, and fever were reported less frequently in pregnant women compared to nonpregnant women.

Rates of adverse events such as miscarriage, preterm birth, stillbirth, birth defects, and neonatal deaths were less than or within expected background rates for the same events in non-vaccinated pregnant women.

"Preliminary findings did not show obvious safety signals among pregnant persons who received mRNA Covid-19 vaccines. However, more longitudinal follow-up, including follow-up of large numbers of women vaccinated earlier in pregnancy, is necessary to inform maternal, pregnancy, and infant outcomes."

Fertility and COVID-19 Vaccination

Fertility: As of May 2021, there is currently no evidence or theoretical mechanism of action in which the currently approved COVID-19 vaccines could adversely affect fertility; there are no data that indicates delay in pregnancy is necessary after COVID-19 vaccination (Rasmussen et al. 2021; RCOG, 2021).

As of May 2021: Vaccination during pregnancy vs. vaccination while breastfeeding (and antibody transfer to fetus/newborn):

Note: There are no comparative studies regarding COVID-19 vaccination antibody transfer during pregnancy vs. breastfeeding, but separate/individual studies have been completed (detailed below). Researchers can also make educated conclusions based on other vaccine data (influenza, pertussis).

BOTH are great options for offering the mother protection against COVID-19 (which is the first goal of vaccination).

Placental transfer (during pregnancy) likely offers more protection (IgG; antibodies “more durable”) than vaccination while breastfeeding (IgA, some IgG; see box) but each method protects differently.

Placental transfer offers systemic protection (gets into blood; antibodies may last as long as 6 to 12 months); breastmilk transfer offers mucosal protection, but is not long lasting; however, being breastfed every few hours would offer some level of sustained [IgA, IgG] protection.

There are three main types of immunoglobins (antibodies; IgA, IgG, IgM). Placental transfer and breast milk transfer offer different types to a fetus/newborn.

IgM: body's first response to a new infection; short-lasting

IgG: produced during an initial infection; remains in the body long-term to prevent re-infection (basis of how vaccinations work)

IgG is the only immunoglobulin that can pass through the placenta and directly into the fetal bloodstream; provides protection to the fetus during pregnancy and to the infant for several months after delivery.

IgA: less common in number than IgG; found in saliva, tears, respiratory and gastric secretions, and breast milk

IgA provides protection against infection in mucosal areas of the body such as the respiratory and the gastrointestinal tracts. IgA transfers through breastmilk and helps protect the infant's respiratory/ gastrointestinal tracts from infection.

Sources: 1. Merck Manuals, "Immunoglobins", 2018. Accessed April 2, 2021. 2. Janeway et al. 2001.

More data is necessary, but breast milk IgA could prevent infection and transmission of infection at the mucosal surface (mouth, throat) for as long as breastfeeding continues.

Therefore, vaccination during pregnancy plus initiation of breastfeeding (prenatal antibodies + breastfeeding antibodies) is likely the most effective strategy, but both methods alone offer an infant protection. The exact strength and length of that protection requires more research.

UPDATED April 15 (data as of April 4): According to the U.S. Vaccine Adverse Effect Reporting System (VAERS), 78,000 pregnant women have received either the Pfizer, Moderna or the Janssen vaccine. There have been 261 reports of adverse events most of which have been mild side-effects already known to occur in the general population.

Regarding pregnancy-specific events, 60 miscarriages, 15 preterm births, 4 cases of preeclampsia, and 3 stillbirths have been reported (among 78,000 people; note: a reported adverse event does NOT necessarily mean the vaccine caused the event). The rates of these reported events are in line with the rates at which these events normally occur (in the same number of unvaccinated pregnant women; known as the background rate).

April 6, 2021: 122 pregnant women and their neonates were assessed for antibody response after maternal vaccination (in pregnancy):

55 women received only one dose of the vaccine and 67 women received both doses of the vaccine by time of giving birth. 85 women received the Pfizer-BioNTech vaccine, while 37 women received the Moderna vaccine. All women tested negative for prior or current COVID-19 infection.

mRNA-based COVID-19 vaccines in pregnant women lead to maternal antibody production as early as 5 days after the first vaccination dose, and passive immunity to the neonate as early as 16 days after the first vaccination dose. The increasing levels of maternal IgG over time, and the increasing placental IgG transfer ratio over time suggest that timing between vaccination and birth may be an important factor to consider (such as vaccination in late second trimester/early third trimester, but more data is necessary).

March 31, 2021: Study of 27 women that received a COVID-19 vaccine during their third trimester of pregnancy; vaccine type was 18 Pfizer, 6 Moderna, and 4 were unknown. Twenty-two women received both vaccine doses prior to delivery with a mean latency of 6 ± 3 weeks.

Most pregnant women who received the COVID-19 mRNA vaccine in the 3rd trimester had transplacental transfer of IgG to the infant, at greater levels than would occur after a COVID-19 infection during pregnancy. The study also found that earlier vaccination may produce greater infant immunity.

March 11, 2021: Compared to COVID-19 infection during pregnancy, COVID-19 vaccination may offer protection against maternal ICU admission, mechanical ventilation or ECMO, maternal death, and vertical transmission; vaccination may also help reduce preterm birth, cesarean section, stillbirth, mother-infant separation at birth, and possible interruption of breastfeeding (due to infection).

March 8, 2021 [Note: pre-print]:  Cohort of 131 reproductive-age vaccine recipients (84 pregnant, 31 lactating, and 16 non-pregnant); vaccine-induced immune responses were equivalent in pregnant and lactating vs non-pregnant women.

  • All titers were higher than those induced by COVID-19 infection during pregnancy.

  • Vaccine-generated antibodies were present in all umbilical cord blood and breastmilk samples.

  • No differences were noted in reactogenicity across the groups.

  • Immune transfer to neonates occurred via placental and breastmilk.

March 5, 2021: Of 30,494 women who have registered in VAERS, there were 122 total adverse events reported, most of which were mild side effects comparable to the general vaccinated population.

Side effects of doses 1 and 2 of either the Pfizer or Moderna vaccines are similar to the non-pregnant population and can include pain at the injection site, fatigue, headache, chills, nausea, muscle pain, and/or fever.

Note: According to CDC, most systemic post-vaccination symptoms are mild to moderate in severity, occur within the first three days of vaccination, and resolve within 1–2 days of onset. These symptoms are more frequent and severe following the second dose.

Of pregnancy-specific adverse events reported (not necessarily due to the vaccine), there were 27 miscarriages, 6 preterm deliveries, and 4 stillbirths. However, these events are in line with the rate at which these events would normally occur (in the non-vaccinated pregnant population).

March 1, 2021: CDC presented vaccine data for pregnant women registered in its V-safe registry who received either the Pfizer or Moderna vaccines:

Of 1,815 pregnant women registered, rates of miscarriage, stillbirth, gestational diabetes, preeclampsia/gestational hypertension, eclampsia, intrauterine growth restriction, preterm birth, congenital anomalies, small for gestational age, and neonatal death were similar to the rates in non-vaccinated pregnant women.

Breastfeeding Specific Data (with COVID-19 Vaccination)

June 18, 2021: Do the antibodies produced in breastmilk after maternal vaccination survive infant digestion? IgA antibodies produced in breastmilk after vaccination appear to resist an infant’s gastric phase of digestion but are degraded during the intestinal phase; IgG antibodies may be prone to degradation in both phases of digestion. More research is necessary to determine if the antibodies produced in breastmilk after vaccination are effective at preventing infant infection, and if they are, for how long.

April 12: Study assessed whether maternal COVID-19 vaccination results in secretion of COVID-19 antibodies into breast milk and evaluated any potential adverse events among women and their infants.

Eighty-four women completed the study, providing 504 breast milk samples. No mother or infant experienced any serious adverse event during the study period. This study found robust secretion of SARS-CoV-2 specific IgA and IgG antibodies in breast milk for 6 weeks after vaccination. IgA secretion was evident as early as 2 weeks after vaccination followed by a spike in IgG after 4 weeks (a week after the second vaccine). Antibodies found in breast milk of these women showed strong neutralizing effects, suggesting a potential protective effect against infection in the infant.

March 30, 2021: Study assessed antibody levels in breastmilk after COVID-19 vaccination with Pfizer-BioNTech; five subjects and 29 human milk samples at the following timepoints of vaccination: prior to, within the first 24 hours of, and weekly following. The study found robust and sustained elevation of antibodies (IgG/IgA) in breastmilk up to 80 days after vaccination (although levels declined gradually as time went on).

March 8, 2021 [Note: pre-print]: "mRNA from anti-COVID vaccines is not detected in human breast milk samples collected 4-48 hours post-vaccine. These results strengthen the recommendation...that lactating individuals who receive the anti-COVID-19 mRNA-based vaccine should continue to breastfeed their infants uninterrupted."

Registries

V-safe is a smartphone-based tool that uses text messaging and web surveys to provide personalized health check-ins after you receive a COVID-19 vaccine. Through v-safe, you can quickly tell CDC if you have any side effects after getting a COVID-19 vaccine. Depending on your answers to the web surveys, someone from CDC may call to check on you and get more information. V-safe will also remind you to get your second COVID-19 vaccine dose if you need one.

V-safe COVID-19 Vaccine Pregnancy Registry: The registry is collecting health information from people who received COVID-19 vaccination in the periconception period (within 30 days before last menstrual period) or during pregnancy. The information is critical to helping people and their healthcare providers make informed decisions about COVID-19 vaccination. Participation is voluntary, and participants may opt out at any time.

Vaccine Adverse Event Reporting System (VAERS): VAERS is a U.S. early warning system to detect possible safety problems in U.S.-licensed vaccines. VAERS is co-managed by the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA). VAERS accepts and analyzes reports of adverse events (possible side effects) after a person has received a vaccination. Anyone can report an adverse event to VAERS.

COVID-19 Vaccines International Pregnancy Exposure Registry: The C-VIPER is open to any woman who is 18 years of age or older, pregnant, and vaccinated against COVID-19 during pregnancy.

Action

The best way to prevent the virus is to avoid being exposed.

Pregnant woman should:

  • Seek care immediately if experiencing a medical emergency. Emergency symptoms can include trouble breathing, persistent pain or pressure in the chest, new confusion, inability to wake or stay awake, or bluish lips or face. This is not an inclusive list, and women should always call their HCP or visit an emergency room when necessary.

  • Report any and all symptoms of a respiratory infection to their HCP, to include cough, fever, shortness of breath, and diarrhea

  • Avoid unnecessary traveling, use of public transportation, and contact with sick people

  • Wear a mask (to protect others) in public settings

  • Quit smoking (risk factor for infection)

  • Follow personal and social distancing rules

  • Regularly wash hands for at least 20 seconds (if soap and water are not readily available, use a hand sanitizer that contains at least 60% alcohol)

  • Avoid touching their eyes, nose, and mouth with unwashed hands.

  • Do not skip prenatal care appointments or other health appointments that may be necessary

  • Tell their HCP if they get tested in a location other than their HCP's office

  • Make sure to have at least a 30-day supply of prescription medications

  • Learn about stress and coping

  • Get adequate sleep and physical exercise

  • Go outside in open areas for walks, fresh air, and a change of scenery

Any pregnant woman who has traveled in a state or country with a high rate of COVID-19 infection or who has had close contact with an individual with confirmed infection should be tested and quarantined.

Women should refer to the CDC and ACOG COVID-19 web pages below for additional information (see Resources).

Note: Stay-at-home orders have increased the risk some women may experience domestic violence. 

Women can:

The National Domestic Violence Hotline can help women create a safety plan and locate resources in their area, if available. Women can call them 24/7 at 1-800-799-7233 or chat live via their website.

Partners/Support

Partners, family members, and other adult family members who live with a pregnant woman need to practice the same hygiene and social distancing habits and procedures as they do.

This includes maintaining a distance of at least 6 feet from other individuals, wearing a mask in public settings, washing hands for at least 20 seconds, and regularly disinfecting commonly touched surfaces in the office or at home.

Household transmission of COVID-19 is common and occurs early after illness onset.

CDC advises that persons should self-isolate immediately at the onset of COVID-like symptoms, at the time of testing as a result of a high risk exposure, or at time of a positive test result, whichever comes first.

All household members, including the infected person case, should wear masks within shared spaces in the household.

Symptoms can include:

  • Fever or chills

  • Cough

  • Shortness of breath or difficulty breathing

  • Fatigue

  • Muscle or body aches

  • Headache

  • New loss of taste or smell

  • Sore throat

  • Congestion or runny nose

  • Nausea or vomiting

  • Diarrhea

Emergency symptoms can include trouble breathing, persistent pain or pressure in the chest, new confusion, inability to wake or stay awake, or bluish lips or face. This is not an inclusive list, and individuals should always call their HCP or visit an emergency room when necessary.

Infected persons should also:

  • Stay home. Most people with COVID-19 have mild illness and can recover at home without medical care. Individuals should remain at home unless they need to seek medical care.

  • Get rest and stay hydrated.

  • Stay in touch with an HCP and seek emergency medical care for difficulty breathing.

  • Avoid public transportation, ride-sharing, or taxis.

Individuals should refer to the CDC COVID-19 page for additional detailed information and resources.

Resources

Total cases in the United States/COVID tracker (U.S. Centers for Disease Control and Prevention

COVID-19 Home Page (U.S. Centers for Disease Control and Prevention)

Management Considerations for Pregnant Patients With COVID-19 (Society for Maternal-Fetal Medicine)

COVID-19 Vaccination of Pregnant or Lactating People (U.S. Centers for Disease Control and Prevention)

Provider Considerations for Engaging in COVID-19 Vaccine Counseling With Pregnant and Lactating Patients (Society for Maternal-Fetal Medicine)

How Do We Know the COVID-19 Vaccines Are Safe and Effective? One Expert Explains. (American College of Obstetricians and Gynecologists; December 2020)

How does the RT-PCR test work? (International Atomic Energy Agency)

Novel Coronavirus 2019 (COVID-19): Practice Advisory (American College of Obstetricians and Gynecologists; December 2020)

Management Algorithm (American College of Obstetricians and Gynecologists and Society for Maternal-Fetal Medicine)

COVID-19 FAQs for Obstetrician-Gynecologists, Obstetrics (American College of Obstetricians and Gynecologists)

References

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