There is currently no evidence women or their babies receive any benefit from fluoride supplementation during pregnancy.
Researchers have theorized that additional supplementation of fluoride during pregnancy – as a baby’s teeth develop prior to delivery – could be an additional preventative step to help the baby avoid cavities during childhood.
However, some researchers indicate that fluoride supplementation during pregnancy is not necessary (and could be dangerous) as fluoride products in childhood are enough for the prevention of childhood cavities.
It is currently assessed that excess fluoride during pregnancy could have toxic effects, but exactly how much fluoride crosses the placenta (and when) is still debated.
Women should talk to their health care provider (HCP) if they have any questions regarding fluoride during pregnancy. Women can also read more information regarding dental appointments and procedures here.
Background
Fluoride, found in various forms in nature, is the most effective way to prevent cavities (caries) and is an ingredient in toothpastes, mouthwashes, tooth varnishes, and fluoride pills.
Once fluoride is absorbed in the stomach and small intestine, it enters the bones and teeth where it can strengthen both. This is the only known human benefit of fluoride; fluoride is not an essential nutrient.
Pregnancy
Fluoride crosses the placenta, but how it does this and how much fluoride gets through to the fetus is not known with certainty.
Some researchers believe fluoride passes freely through the placenta, while others believe the placenta acts as a barrier, with fluoride passing through in low concentrations.
It does appear, however, that on average, the concentration of fluoride in the placenta is about 60% of the concentration in the mother`s bloodstream.
It has been theorized that fluoride supplementation should be considered during pregnancy so the fetus’ developing teeth can benefit from fluoride, thereby beginning the cavity prevention process at the very start. However, this is not widely accepted and continues to be debated (a child's baby and permanent teeth are both formed during pregnancy).
Some studies show fluoride supplementation during pregnancy provides no extra advantage if that child has access to fluorinated drinking water and dental hygiene products during childhood.
Further, too much fluoride during pregnancy may be harmful (see Excess). At least one study (2019) suggested the maximum allowable amount during pregnancy may need to be lowered, based on a link between normal fluoride consumption in pregnant women and lower IQ scores in their children (Note: this study is controversial regarding significance).
Excess Fluoride
An adequate intake of fluoride is determined to be 1.5 to 4.0 milligrams (mg)/day for adults, with an upper limit of 10 mg/day. It is recommended pregnant women obtain 3.0 mg/day.
An excess of fluoride can cause health problems, most commonly a condition called fluorosis, which changes the appearance of tooth enamel from white spots to pits/decay.
Excess fluoride can also be toxic. Poisoning mainly occurs today due to unsupervised ingestion of toothpaste and mouthwash (toddlers and school-aged children) and over-fluoridated water.
Fluoride accumulates in bones, and when it exceeds 5 to 20 mg/day for an extended period of time (chronic toxicity) it weakens bones, increases the risk of bone fractures, and potentially causes subtle neurological symptoms.
The probable toxic dose (the minimal dose that could trigger serious and life-threatening signs and symptoms requiring immediate treatment) is defined at 5 mg per kilogram (kg) of body mass (equating to approximately 340 mg for a 150 pound/68 kg woman).
Symptoms of possible poisoning include nausea, abdominal pain, bloody vomiting, and diarrhea, followed by paleness, weakness, shallow breathing, weak heart sounds, wet, cold skin, cyanosis, dilated pupils, and even death, which can sometimes occur within hours (if a high amount was taken in a short amount of time).
Supplementation
There is currently no evidence pregnant women or their babies receive any benefit from fluoride supplementation during pregnancy; therefore, supplementation is not recommended.
Dentists may recommend prescription toothpastes or fluoride rinses during pregnancy; these are considered safe when used properly (see Teeth and Gums).
Food Sources
Humans consume fluoride every day, but in small amounts; it can be found in meat, fish, cereals, canned anchovies, canned fruits, ground chicken meat products, chocolate milk, and fluorinated water. Some countries have fluorinated milk, salt, and water (see Resources).
Action
Women who may be concerned about their fluoride exposure during pregnancy should talk with their HCP.
Resources
Community Water Fluoridation (Centers for Disease Control and Prevention)
Water System Information by State (Centers for Disease Control and Prevention)