Medications to Avoid While Pregnant: Safety Warnings and Safe Alternatives

When you're pregnant, every pill, drop, or spray feels like a decision that could change your baby’s life. You want to feel better-whether it’s a headache, stuffy nose, or back pain-but you’re terrified of doing something that might hurt your growing child. The truth is, medications to avoid during pregnancy aren’t just old wives’ tales. Some common drugs carry real, documented risks that can lead to birth defects, preterm birth, or long-term developmental issues. And the advice keeps changing. What was considered safe last year might now come with a warning.

What’s Really Dangerous in the First Trimester?

The first 12 weeks of pregnancy are when your baby’s organs are forming. This is the most sensitive time. Even small exposures can cause major problems. Some medications are absolute no-gos during this stage.

Isotretinoin (Accutane), used for severe acne, is one of the most dangerous. It doesn’t just increase the chance of birth defects-it causes them in more than 25% of cases. These include missing ears, heart problems, and brain abnormalities. If you’re on this drug and thinking about getting pregnant, stop it at least one month before trying-better yet, talk to your doctor about switching to a safer acne treatment like topical benzoyl peroxide or azelaic acid.

ACE inhibitors like lisinopril and ARBs like valsartan, often used for high blood pressure, are also dangerous early on. They can cause fetal kidney failure, low amniotic fluid, and even death. If you’re on one of these and find out you’re pregnant, don’t panic-but do call your doctor immediately. There are safer blood pressure medications like methyldopa or labetalol that won’t cross the placenta the same way.

Warfarin (Coumadin), a blood thinner, is another big risk. It can cause fetal warfarin syndrome, which includes underdeveloped noses, bone problems, and intellectual disabilities. If you need blood thinning during pregnancy, low molecular weight heparin (like Lovenox) is the standard replacement because it doesn’t cross the placenta.

NSAIDs: The Hidden Risk After Week 20

Ibuprofen (Advil, Motrin) and naproxen (Aleve) are so common, many people think they’re harmless. But the FDA issued a clear warning in 2020: don’t take them after 20 weeks of pregnancy. Why? They can shut down your baby’s kidney function, leading to dangerously low amniotic fluid (oligohydramnios). This can cause lung underdevelopment and limb contractures. Studies show the risk doubles after 20 weeks.

Even aspirin is risky unless it’s prescribed at a low dose (60-150 mg daily) for preventing preeclampsia. Regular-strength aspirin (325 mg or more) can increase bleeding risks during delivery and delay labor.

Acetaminophen: The New Controversy

For years, acetaminophen (Tylenol) was the gold standard for pain and fever relief in pregnancy. But in September 2025, the FDA issued a notice to physicians saying the evidence now supports caution. A 2021 study of 95,000 children found that long-term use-especially daily use throughout pregnancy-was linked to a 28.6% higher risk of ADHD and a 20.4% higher risk of autism spectrum disorder.

This doesn’t mean you can’t use it. If you have a high fever (102°F or above), not treating it is riskier than taking acetaminophen. Studies show fever itself can increase the chance of neural tube defects by over eight times. The key is to use the lowest dose possible for the shortest time. Stick to 325-650 mg every 4-6 hours, and never exceed 3,000 mg in a day. Avoid daily use for headaches or mild pain unless your doctor says it’s necessary.

Antibiotics and Other Prescription Risks

Not all antibiotics are safe. Tetracyclines like doxycycline can permanently stain your baby’s teeth and slow bone growth. Fluoroquinolones like ciprofloxacin have been linked to a 1.9 times higher risk of joint and muscle problems in children. Both should be avoided.

Instead, penicillins (like amoxicillin) and cephalosporins (like cephalexin) are considered safe and are often first choices for infections during pregnancy. Always tell your doctor you’re pregnant before taking any antibiotic-even if it’s for a urinary tract infection or sinus infection.

Valproic acid (Depakote), used for epilepsy and bipolar disorder, carries a 10.7% risk of major birth defects-far higher than the 2.8% baseline. If you have epilepsy and are planning pregnancy, talk to your neurologist about switching to lamotrigine or levetiracetam, which have much safer profiles.

Safe Alternatives for Common Pregnancy Complaints

You don’t have to suffer. There are safe, effective ways to manage everyday discomforts.

• Pain and fever: Acetaminophen (Tylenol), used carefully, is still the best option. Avoid NSAIDs after 20 weeks.
• Allergies: Loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra) are all Category B and have been studied in thousands of pregnancies with no increased risk of birth defects.
• Nasal congestion: Start with saline sprays and a humidifier. If you need more, pseudoephedrine (Sudafed) is okay after the first trimester-just don’t exceed 120 mg per day. Avoid it if you have high blood pressure.
• Constipation: Eat more fiber (25-30 grams daily), drink water, and move around. If that doesn’t help, docusate sodium (Colace) or polyethylene glycol (Miralax) are both safe and effective.
• Heartburn: Try eating smaller meals, staying upright after eating, and avoiding spicy or fatty foods. Calcium-based antacids like Tums are safe. Avoid those with sodium bicarbonate or magnesium trisilicate.

Antidepressants: Weighing the Risks

Untreated depression during pregnancy can be just as harmful as medication. It increases the risk of preterm birth by 64% and low birth weight by 73%. So stopping your antidepressant cold turkey isn’t always the answer.

Paroxetine (Paxil) is linked to a slightly higher risk of heart defects-about 1.5-2% compared to 0.7% in the general population. But other SSRIs like sertraline (Zoloft) and citalopram (Celexa) have much better safety data. If you’re on an antidepressant and pregnant, don’t stop without talking to your doctor. A 2016 study of 3,000 women found that stopping SSRIs raised the chance of depression relapse to 68%. The risk of PPHN (persistent pulmonary hypertension in newborns) goes from 1-2 per 1,000 to 5-6 per 1,000 with SSRI use-but the risk of untreated depression is higher.

What to Do Before and During Pregnancy

The best way to protect your baby is to plan ahead.

• Before conception: Review every medication you take-prescription, over-the-counter, and supplements-with your doctor. Switch out risky drugs like isotretinoin or valproate before you get pregnant.
• During pregnancy: Keep a written list of everything you take, including herbal teas and vitamins. Many women don’t realize that some supplements can be harmful. For example, high-dose vitamin A (over 10,000 IU daily) can cause birth defects.
• Ask questions: If you’re unsure about a medication, call MotherToBaby (1-866-626-6847). They’re a free, confidential service staffed by specialists who answer over 100,000 questions a year. They’ve helped 2.3 million families since 2022.

What’s Changing in 2025 and Beyond

The science is evolving fast. The FDA’s 2025 notice on acetaminophen is just the beginning. A major global study-the Acetaminophen Birth Cohort Study-is tracking 50,000 pregnant women across 15 countries, following their children until age 10. Results are expected by the end of 2025.

Meanwhile, the NIH is investing $15 million into non-opioid pain options for pregnant women, including acupuncture, physical therapy, and mindfulness techniques. ACOG plans to update its guidelines in 2026 to reflect the new data.

The message is clear: don’t assume anything is safe just because it’s available over the counter. And don’t assume everything is dangerous just because you’re pregnant. The right answer is often somewhere in between.

Next Steps: What to Do Today

If you’re pregnant or planning to be:

• Make a list of every medication, supplement, and herbal product you take.
• Call your doctor or midwife to review it-don’t wait for your next appointment.
• Download the MotherToBaby app or call 1-866-626-6847 for free, expert advice.
• If you’re on a medication for a chronic condition, ask about switching to a safer alternative before conception.
• When in doubt, don’t take it. But also don’t stop a necessary medication without talking to your provider.

The goal isn’t to live in fear. It’s to make informed choices. Pregnancy is already full of changes. You don’t need to guess about what’s safe. Help is available-and you’re not alone.