Safety information for pregnant and breastfeeding patients
Always consult your doctor: Medication safety in pregnancy is complex and depends on the benefit-risk balance for your specific situation. Never stop or start medications during pregnancy without medical guidance.
FDA Pregnancy Category Contraindicated
Consult your healthcare provider for the most current pregnancy safety information.
The first trimester is the period of organogenesis — when major organ systems develop. Medicine exposure during this period carries the highest risk of structural birth defects. The risk is greatest between weeks 5–10 when the heart, limbs, and neural tube form.
Major structural development is complete by the second trimester, but organ maturation continues. Medicine exposure during this period may affect fetal growth and functional development. Some medicines can cause fetal growth restriction.
Medicines taken near delivery can affect the newborn. Some medicines (NSAIDs, SSRIs, benzodiazepines) should be discontinued or tapered before delivery. Neonatal withdrawal syndromes can occur with opioids, benzodiazepines, and SSRIs if taken throughout pregnancy.
Most medicines pass into breast milk to some degree. The amount an infant receives depends on: maternal medicine concentration in plasma, the medicine's molecular weight, protein binding, lipid solubility, oral bioavailability in the infant, and timing of feeding relative to maternal dose.
For medicine-specific breastfeeding information, the LactMed database(National Library of Medicine) is the most comprehensive and regularly updated resource. The relative infant dose (RID) — the percentage of the maternal weight-adjusted dose that the infant receives — is the standard metric for assessing breastfeeding safety. An RID of <10% is generally considered acceptable for most medicines.