Medications to Avoid While Pregnant: Safety Warnings and Safe Alternatives

When you're pregnant, every pill, drop, or supplement feels like a decision that could change your baby’s life. You want to relieve a headache, calm a stuffy nose, or manage chronic pain-but you also don’t want to risk harm. The truth is, medications to avoid during pregnancy aren’t always obvious. Some over-the-counter drugs you’ve used for years can pose real dangers, and even the ones doctors used to say were safe are now under new scrutiny.

What’s Really Dangerous in the First Trimester?

The first 12 weeks of pregnancy are when your baby’s organs form. This is the most sensitive time for medication exposure. Certain drugs can cause major birth defects, and some have been proven to do so in thousands of cases.

Isotretinoin (Accutane), used for severe acne, is one of the most dangerous. It doesn’t just increase risk-it guarantees it. More than 25% of babies exposed to isotretinoin in early pregnancy develop serious defects: cleft palates, heart problems, missing ears, and brain abnormalities. The FDA’s iPLEDGE program requires strict controls for this drug, but women still get pregnant while taking it. If you’re on isotretinoin and thinking about pregnancy, stop at least one month before trying to conceive-and use two forms of birth control while taking it.

ACE inhibitors and ARBs, common blood pressure meds like lisinopril and valsartan, are another major red flag. These drugs can cause kidney failure in the fetus, low amniotic fluid, and even stillbirth. If you’re on one of these and find out you’re pregnant, don’t panic-but don’t wait. Call your doctor immediately. There are safer alternatives like labetalol or methyldopa that are well-studied and approved for use during pregnancy.

Warfarin (Coumadin), a blood thinner, crosses the placenta and can cause fetal warfarin syndrome. This leads to underdeveloped bones, a flattened nose, and eye problems. If you’re on warfarin and planning a pregnancy, switch to enoxaparin (Lovenox) before conception. Enoxaparin doesn’t cross the placenta, making it the standard of care for women who need blood thinners during pregnancy.

Valproic acid, used for epilepsy and bipolar disorder, carries a 10.7% risk of major birth defects-more than three times the normal rate. Babies exposed to it have higher chances of neural tube defects, heart problems, and lifelong learning disabilities. If you have epilepsy and are planning pregnancy, talk to your neurologist about switching to lamotrigine or levetiracetam. Studies show these alternatives cut the risk of birth defects to around 2-3%.

NSAIDs: The Hidden Risk After Week 20

Many women think ibuprofen and naproxen are harmless. They’re in medicine cabinets everywhere. But starting at 20 weeks of pregnancy, these drugs can cause serious problems for your baby.

The FDA issued a warning in October 2020: NSAIDs can lead to fetal kidney failure, which causes low amniotic fluid (oligohydramnios). This fluid cushions and protects the baby. Too little can mean underdeveloped lungs, compressed limbs, and even death. Studies show the risk doubles after 20 weeks. That’s why doctors now say: no ibuprofen, no naproxen, no aspirin (except low-dose aspirin for preeclampsia prevention, which is a special case).

Even if you took ibuprofen at 18 weeks, don’t panic. But if you’re past 20 weeks and still using it regularly, stop now. Talk to your provider about acetaminophen instead-or non-drug options like warm compresses, massage, or gentle stretching.

The Acetaminophen Debate: Safer? Or Not?

For decades, acetaminophen (Tylenol) was the go-to for fever and pain in pregnancy. It was labeled “Category B” by the FDA-meaning no evidence of harm in humans. But that’s changed.

In September 2025, the FDA issued a new notice to physicians: prolonged use of acetaminophen during pregnancy may be linked to higher risks of ADHD and autism in children. A 2021 JAMA Pediatrics study of 95,000 mother-child pairs found a 28.6% increased risk of ADHD and a 20.4% increased risk of autism spectrum disorder when acetaminophen was used for more than a few days in a row, especially if taken throughout pregnancy.

But here’s the catch: untreated fever is even more dangerous. A 2020 meta-analysis found that a mother’s fever above 102°F increases the risk of neural tube defects by 8.2 times. So if you have a high fever, taking acetaminophen is still the right move.

The key is dose and duration. Use the lowest amount for the shortest time. Don’t take it daily for headaches or colds. Stick to 325-650 mg every 4-6 hours, and never exceed 3,000 mg per day. If you’re taking it for more than a week, talk to your provider. There’s no proof it causes autism or ADHD outright-but the signal is strong enough that caution is now the standard.

Antibiotics and Other Common Drugs to Skip

Not all antibiotics are safe. Tetracyclines like doxycycline can permanently stain your baby’s teeth and weaken their bones. Avoid them completely during pregnancy. Fluoroquinolones like ciprofloxacin are linked to a 1.9-fold higher risk of musculoskeletal problems in children. Stick to penicillin, amoxicillin, or cephalosporins-they’re well-studied and safe.

For allergies, second-generation antihistamines are your best bet. Loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra) have been studied in over 2,000 pregnancies with no increased risk of birth defects. Avoid first-generation ones like diphenhydramine (Benadryl) long-term-they can cause drowsiness in the baby and aren’t as safe for regular use.

For nasal congestion, start with saline sprays. If you need more, pseudoephedrine (Sudafed) is okay after the first trimester, but only at 30-60 mg every 4-6 hours, and never more than 120 mg a day. It can raise your blood pressure, so skip it if you have hypertension.

Managing Chronic Conditions During Pregnancy

If you have diabetes, asthma, depression, or epilepsy, stopping your meds isn’t the answer. Untreated conditions can be far more dangerous than the meds themselves.

For depression, paroxetine (Paxil) carries a small risk of heart defects (1.5-2% vs. 0.7% baseline). But if you stop your antidepressant, your chance of relapse jumps to 20-25%. That increases your risk of preterm birth by 64% and low birth weight by 73%. The best approach? Stay on a safe SSRI like sertraline or escitalopram, under close supervision.

For asthma, uncontrolled symptoms can starve your baby of oxygen. Inhaled corticosteroids like budesonide are safe and recommended. Don’t skip your inhaler.

For diabetes, insulin is safe. Oral meds like metformin are also used, but insulin remains the gold standard. Work with your endocrinologist to adjust your plan before conception.

Safe Alternatives for Common Ailments

You don’t need pills for everything. Here’s what works without drugs:

• Headaches: Cold compresses, rest, hydration, and gentle neck stretches.
• Heartburn: Eat smaller meals, avoid spicy or fatty foods, sleep propped up, and try ginger tea or calcium carbonate (Tums) if needed.
• Constipation: Aim for 25-30 grams of fiber daily (oats, beans, apples, chia seeds). Drink at least 8-10 glasses of water. If you need help, docusate sodium (Colace) or polyethylene glycol (Miralax) are safe, with no increased risk of birth defects in over 700 documented pregnancies.
• Back pain: Prenatal yoga, physical therapy, and supportive belly bands help more than painkillers.

What to Do Right Now

If you’re pregnant or planning to be, here’s your action list:

1. Make a full list of every medication, supplement, and OTC drug you take-including herbal teas and vitamins.
2. Bring it to your OB/GYN or midwife at your first appointment. Don’t assume they’ll ask.
3. Use the MotherToBaby service (1-866-626-6847 or mothertobaby.org). They provide free, expert advice on medication safety and have answered over 2.3 million questions annually.
4. Check the FDA’s Pregnancy and Lactation Labeling Rule (PLLR) for any drug you’re unsure about. It’s now written in plain language, not coded categories.
5. Never start or stop a prescription without talking to your provider-even if it’s something you’ve taken for years.

Many women worry they’ve already taken something harmful. That’s normal. The MotherToBaby service reports that 78% of their calls come from women who’ve already taken a risky medication. The good news? Most exposures don’t lead to problems. What matters now is what you do next.

Final Thoughts

There’s no perfect list of “safe” and “unsafe” drugs for pregnancy. Science changes. New data comes out. What was safe last year might be questioned today. That’s why personalized care matters more than ever.

Your body is doing something incredible. You don’t need to be perfect-you just need to be informed. Ask questions. Speak up. Use trusted resources. And remember: the goal isn’t to avoid all medication. It’s to use the right ones, at the right time, for the right reason.