During pregnancy, the body can become unusually sensitive to herbs, supplements, medicines and other compounds that might ordinarily be safe. Several medicinal herbs may increase the risk of miscarriage, birth defects, stillbirth and other serious pregnancy-related complications. Lavender, a flowering herb noted for its relaxing properties, may be used to brew medicinal tea. Because it has not been studied sufficiently for its effects on pregnancy, lavender tea should generally be avoided during pregnancy.
In general, small to moderate amounts of lavender are ultimately safe. The U.S. Food and Drug Administration includes lavender on the list of generally recognized as safe, or GRAS for short, list of food additives. Inclusion as a GRAS item means that a plant or compound is safe for the majority of individuals when used in the amounts commonly found in food. This means that the FDA recognizes lavender as safe when used as an herbal seasoning, for example, lavender-flavored desserts.
When used in medicinal quantities, such as in teas made predominantly or exclusively with the herb, lavender may be unsafe. The University of Maryland Medical Center advises against the use of lavender supplements and teas for pregnant and nursing women. According to the National Institutes of Health, studies have not investigated whether medicinal quantities of lavender have any negative effects on fetal development or gestation. As a precaution, pregnant women should generally avoid the herbal tea except under the guidance of an an informed practitioner.
Lavender tea has been associated with several side effects, which may affect either a pregnant woman or her developing fetus. The NIH notes that lavender oil can disrupt certain hormones, rarely leading to side effects such as breast development in boys. It is unclear if lavender tea could notably alter the hormones that govern pregnancy. Other common side effects include constipation, headache and increased appetite.
Lavender's GRAS status implies that it would be safe when used in small quantities to add flavor to other teas. For example, a black or white tea containing lavender flavor would generally be considered safe during pregnancy when used in reasonable quantities. However, in some special circumstances, lavender tea is particularly dangerous to expectant mothers. Women using sedative medications, which are generally not recommended during pregnancy, should be particularly cautious of lavender and herbs with sedative properties. Always consult an obstetrician or midwife before taking any medicinal herb in pregnancy.