Taking medications to treat new or existing health conditions during pregnancy is common—about 90% of pregnant people take over-the-counter (OTC) medications, and 70% take prescription medications. Many medicines are safe during pregnancy, but some can pose serious risks for you or the fetus, such as pregnancy loss, preterm birth, and congenital disorders (previously known as birth defects). Knowing which medications to avoid while pregnant is essential for protecting your and your baby’s health and well-being. Always consult a healthcare provider before taking any medications, including prescription and OTC. They can discuss the safest and most effective medication options for managing your health conditions or concerns during pregnancy.
13 Medications You Should Avoid While Pregnant
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)
NSAIDs—such as Advil (ibuprofen), Aleve (naproxen), and Ecotrin (aspirin)—help reduce pain, inflammation, and fever. NSAIDs can cause serious kidney problems in a fetus, especially after 20 weeks (5 months) gestation. After 20 weeks, the fetus’s kidneys produce most of the protective amniotic fluid surrounding the fetus, which is essential for developing the lungs, muscles, and digestive system.
While NSAID use is most dangerous after 20 weeks of pregnancy, you may want to avoid the drugs throughout your entire pregnancy. Some evidence suggests NSAIDs increase the risk of miscarriage and birth defects when taken in early pregnancy.
Statins
Statins are prescription medications that lower blood cholesterol levels in people with high cholesterol. They work by reducing cholesterol production in the liver and helping the liver remove low-density lipoprotein (LDL)—bad cholesterol—from the blood.
In 2021, the U.S. Food and Drug Administration (FDA) removed the strongest warning against statin use during pregnancy after acknowledging research evidence that shows statins do not cause birth defects. However, statins are associated with other risks during pregnancy, including a higher risk of low birth weight and preterm birth.
Retinoids
Retinoids, such as Zenatane (isotretinoin), are prescription acne medications associated with a high risk of severe birth defects. These medications affect how cells grow and divide, disrupting the normal development of an embryo or fetus. Retinoid use during pregnancy is associated with malformations (e.g., cleft lip or palate; abnormal head shape), heart defects, intellectual disabilities, and developmental delays.
Although oral retinoids are particularly dangerous for a fetus, there is not enough research to determine whether topical retinoids (creams and lotions) are safe. Some experts recommend avoiding them entirely during pregnancy.
Warfarin (Blood Thinner)
Blood thinners, or anticoagulants, are prescription medications that help prevent blood clots. Coumadin (warfarin) is a blood thinner that passes through the placenta to the fetus and increases the risk of miscarriage, stillbirth, and congenital disorders.
Warfarin use in the first trimester is associated with fetal warfarin syndrome (FWS), which causes skeletal problems such as shortened limbs, skull and facial differences, intellectual disability, and heart defects. In the second and third trimesters, warfarin use increases the risk of hemorrhage (excessive bleeding) and stillbirth. Fortunately, there are blood thinners that are safe to take during pregnancy, such as heparin, that do not pose health risks to a developing fetus.
Anti-Seizure Medications
Anti-seizure medications (ACMs) help reduce the frequency of seizures in people with seizure disorders, such as epilepsy. Some ACMs, particularly Valproic (valproic acid), increase the risk of congenital disorders. Valproic acid exposure in the first trimester is associated with a high risk of babies born with neural tube defects, such as spina bifida, cleft lip, and heart defects. Exposure in the first trimester is also associated with an increased risk of intellectual disabilities, autism spectrum disorder, facial differences, and limb defects.
The decision of whether or not to take ACMs during pregnancy involves weighing the risks of uncontrolled seizures for both the pregnant parent and fetus against the potential birth risks. Your healthcare provider can advise you based on your specific health needs.
Tetracycline Antibiotics
Tetracyclines, such as Monodox (doxycycline), are antibiotics that treat many bacterial infections, including respiratory tract infections and skin, eye, intestinal, and urinary tract infections. During pregnancy, these medications can affect bone growth and cause permanent staining of a baby’s teeth. While less common, tetracycline may slow bone growth in the developing fetus. However, this effect appears to be reversible once the pregnant parent stops taking the medication. High-dose tetracyclines also pose a health risk for pregnant people, increasing the risk of acute fatty liver in pregnancy (AFLP), a rare but possibly life-threatening disorder. Healthcare providers can prescribe safer antibiotics to treat bacterial infections during pregnancy.
Benzodiazepines
Benzodiazepines (like Valium) are sedative medications that treat anxiety and insomnia. Some studies suggest a possible link between first-trimester exposure to benzodiazepines and an increased risk of heart problems. The risk may be dose-dependent, meaning a higher dose could lead to a greater risk. Long-term use of benzodiazepines throughout pregnancy may affect the developing fetus’s central nervous system and increase the risk of preterm birth and low birth weight. Newborns exposed to benzodiazepines may experience respiratory distress, low muscle tone, and poor feeding and require admission to the neonatal intensive care unit (NICU).
Decongestants
Decongestant medications containing Sudafed (pseudoephedrine) can help relieve nasal congestion from allergic rhinitis (hay fever). Some evidence suggests there is a link between pseudoephedrine use in the first trimester and an increased risk of congenital disorders, including gastroschisis (an opening in the abdominal wall), small intestinal atresia (underdeveloped small intestine), and hemifacial microsomia (smaller than usual facial features). Pseudoephedrine acts as a vasoconstrictor, meaning it narrows blood vessels. This may reduce blood flow to the uterus and fetus, especially during the first trimester when organ formation occurs.
ACE Inhibitors
Angiotensin-converting enzyme (ACE) inhibitors, such as Lotensin (benazepril) and Zestril (lisinopril), are prescription medications that treat hypertension (high blood pressure), heart disease, and kidney problems. These medications pose potentially serious risks for a fetus, particularly in the second and third trimesters. ACE inhibitors can cause low levels of amniotic fluid in the womb, increasing the risk of congenital disorders, including lung and kidney problems, skull deformities, and, in severe cases, fetal death.
Methotrexate
Trexall (methotrexate) is a medication that blocks the growth of cells and decreases immune system activity to treat autoimmune conditions like rheumatoid arthritis and certain types of cancer. Methotrexate poses serious risks during pregnancy. Exposure in the first trimester is associated with congenital anomalies such as craniofacial (face and skull), finger and toe, and spinal defects. Exposure to methotrexate in the first trimester also increases the risk of lung, heart, and kidney problems. Studies suggest that low-dose methotrexate may increase the risk of miscarriage, preterm birth, or intrauterine growth restriction (IUGR) that may stunt growth through infancy and childhood.
Cannabis
Cannabis (marijuana) is a plant that some people use to treat anxiety, insomnia, nausea, and pain. Cannabis contains tetrahydrocannabinol (THC), a psychoactive compound that crosses the placenta and affects fetal development. Smoking, vaping, or ingesting cannabis edibles during pregnancy can lead to adverse outcomes such as low birth weight, preterm birth, and developmental delays. Some studies suggest the effects may continue throughout childhood—some children whose gestational parents used cannabis while pregnant have behavioral and learning problems.
Lithium
Lithium, a mood-stabilizing prescription medication for treating bipolar disorder, poses potential risks during pregnancy. First-trimester lithium exposure increases the risk of heart defects in developing fetuses, such as Ebstein anomaly, which affects the positioning and function of a heart valve. Some studies suggest lithium use during pregnancy may increase the risk of preterm birth and low birth weight, though the risk appears to be small. However, lithium use is associated with neonatal complications, such as respiratory distress, poor feeding, and low muscle tone, requiring longer hospital stays after birth. Many people with bipolar disorder who take lithium during pregnancy deliver healthy babies. However, your healthcare provider may recommend lowering your lithium dose to prevent adverse outcomes. Talk to your provider before stopping or reducing your medication.
Opioids
Opioids, such as buprenorphine, codeine, and oxycodone, are powerful pain medications that help manage moderate to severe pain. Opioid use during pregnancy is associated with an increased risk of miscarriage, stillbirth, and congenital disorders, including heart defects, neural tube defects (e.g., spina bifida), and eye problems like glaucoma and blindness. Opioid exposure can lead to neonatal abstinence syndrome (NAS) when a baby goes through withdrawal from the drug after birth. Babies with NAS may cry excessively, have body shakes or seizures, breathing problems, diarrhea, fever, or have trouble eating and gaining weight.
Other Therapies To Avoid
While many natural remedies and supplements are generally safe, some can pose significant risks during pregnancy.
Herbs
Herbs to avoid during pregnancy include:
Black and blue cohosh: These herbs can cause uterine contractions and induce preterm labor. High doses of blue cohosh herb are associated with stroke, heart attack, and respiratory distress in infants.
Dong quai: This increases the risk of miscarriage or preterm birth due to its blood-thinning properties and ability to stimulate uterine contractions.
Goldenseal: This contains a chemical called berberine, which can cross through the placenta and may cause brain damage called kernicterus in infants exposed to goldenseal during pregnancy.
Essential Oils
Essential oils are popular for aromatherapy and topical use, but some can be unsafe during pregnancy. Essential oils to avoid include:
- Anise
- Sage
- Fennel
- Pennyroyal
- Wintergreen
- Myrrh
- Oregano
- Yarrow
- Wormwood
- Mugwort
- High Doses of Vitamins
Prenatal vitamins are important for a healthy pregnancy, but excessive intake of certain vitamins may be unsafe during pregnancy, especially in high doses. For example, excessive intake of vitamin A during pregnancy increases the risk of birth defects and miscarriage. Also, high doses of vitamin E during pregnancy are associated with an increased risk of intrauterine growth restriction, premature rupture of membranes (water breaking early), placental abruption, preterm birth, and stillbirth.
How To Know If a Medication Is Safe To Take
Navigating medications and their safety during pregnancy can be confusing. In the United States, prescription and over-the-counter (OTC) medications have information on the packaging or medication insert regarding the medicine’s safety during pregnancy. This information includes:
Risk summary: A summary of research findings about the potential risks of exposure to the medication during pregnancy, including known birth defects and the risk of miscarriage
Clinical considerations: Additional information on the risk-to-benefit ratio and dose adjustments during pregnancy
Data: A brief summary of the evidence supporting the information included in the risk summary section
Always consult your healthcare provider before taking any medications, including OTC drugs and supplements, while pregnant. Your provider will consider your medical history, the medication’s purpose, and the stage of your pregnancy to determine if a medication is safe.
A Quick Review
Pregnancy requires extra attention and consideration before taking medications and supplements. In the first trimester, certain medications can cause congenital disorders or lead to miscarriage. Other medications may be harmful in the second and third trimesters, increasing the risk of preterm birth, low birth weight, or developmental delays in infants and children.
When it comes to your pregnancy and the health of your developing baby, prioritize erring on the side of caution and avoid taking any medications without your healthcare provider’s approval.
