Benzodiazepines and Birth Defect Risks: What Pregnant Women Need to Know

When you're pregnant and struggling with anxiety or insomnia, the pressure to feel better can be overwhelming. Many women turn to benzodiazepines-medications like lorazepam, diazepam, or alprazolam-because they work quickly and effectively. But what happens when you’re carrying a baby? The truth is, these drugs cross the placenta. They don’t just affect you-they reach your developing fetus. And while not every woman who takes them will have a baby with problems, the risks are real, measurable, and often misunderstood.

What Are Benzodiazepines, and Why Are They Used in Pregnancy?

Benzodiazepines are a class of drugs developed in the 1950s to calm the nervous system. They’re prescribed for anxiety, panic attacks, muscle spasms, and sleep disorders. About 1.7% of pregnant women in the U.S. get a prescription for one during the first trimester, and that number has been rising over the last decade. For some, it’s the only thing that brings relief when therapy and lifestyle changes aren’t enough.

But here’s the catch: these drugs don’t stay in your bloodstream. They travel straight to the baby. Studies show they accumulate in fetal tissue, where they can interfere with brain development, organ formation, and even the timing of labor. That’s why doctors now warn against using them unless absolutely necessary-especially during the first 12 weeks, when the baby’s organs are forming.

What Birth Defects Are Linked to Benzodiazepines?

The data isn’t simple. Some studies say there’s no major risk. Others say the opposite. But the most comprehensive research-like the 2022 study of 3.1 million pregnancies in South Korea-points to a small but real increase in certain birth defects when benzodiazepines are taken in early pregnancy.

Specifically, the risk goes up for:

• Heart defects-about 14 extra cases per 1,000 exposed pregnancies
• Abdominal wall defects-like omphalocele or gastroschisis
• Dandy-Walker malformation-a rare brain structure abnormality
• Anophthalmia or microphthalmia-missing or underdeveloped eyes
• Esophageal atresia-a blockage in the tube connecting the mouth to the stomach

These defects are rare overall. But when they happen, they’re serious. What’s more concerning is that alprazolam (Xanax) appears to carry the highest risk for eye and esophageal defects. One study found women who took alprazolam were four times more likely to have a baby with missing or tiny eyes. That’s not a common outcome-but it’s not a fluke either.

And while the overall risk of any major birth defect only increases from about 2.9% to 3.8% with benzodiazepine use, that’s still an extra 9 out of every 1,000 babies. For some families, that’s too high a price to pay.

It’s Not Just Birth Defects-Other Risks Are Real Too

Benzodiazepines don’t just affect development. They’re also linked to:

• Higher miscarriage risk-up to 85% higher in some studies
• Preterm birth-babies born before 37 weeks
• Low birth weight-babies weighing less than 5.5 pounds
• Low Apgar scores-a sign the baby isn’t adapting well after birth
• Neonatal withdrawal-irritability, tremors, feeding problems in newborns

Even taking these drugs in the 90 days before conception might raise the risk of ectopic pregnancy. That’s a life-threatening condition where the embryo implants outside the uterus. It’s not clear if the drug itself causes this-or if it’s tied to the underlying anxiety or insomnia. But either way, it’s another reason to pause before starting or continuing these medications.

Not All Benzodiazepines Are the Same

Some studies suggest alprazolam is riskier than others. Diazepam and lorazepam show lower or no increased risk for certain defects. But that doesn’t mean they’re safe. The problem is, we still don’t have enough data to say which one is the “least bad.”

What we do know is this: higher doses mean higher risks. The South Korean study found that women taking more than 2.5 mg per day of lorazepam-equivalent had significantly higher chances of heart defects. That’s about one 1 mg tablet of alprazolam daily. So even low doses aren’t risk-free.

What Do Experts Recommend?

Major medical groups agree: avoid benzodiazepines in pregnancy if you can.

• The American College of Obstetricians and Gynecologists (ACOG) says they should be avoided in the first trimester unless no other option exists.
• The American Psychiatric Association urges doctors to weigh risks case by case-considering the drug, the dose, and how long it’s been taken.
• Canada’s guidelines say these drugs should generally be avoided, but may be used in rare, severe cases with close monitoring.
• The U.S. FDA classifies them as Category D-meaning there’s clear evidence of fetal harm.

And here’s the most important part: stopping suddenly can be dangerous. Withdrawal from benzodiazepines during pregnancy can trigger seizures, severe anxiety, or even preterm labor. If you’re on one and pregnant-or planning to be-don’t quit cold turkey. Talk to your doctor.

What Are the Alternatives?

There are safer ways to manage anxiety and sleep problems during pregnancy.

• Cognitive Behavioral Therapy (CBT) is proven to work as well as medication for anxiety and insomnia-with no risk to the baby.
• Mindfulness and meditation reduce stress hormones and improve sleep quality.
• Regular exercise like walking or prenatal yoga helps regulate mood and sleep cycles.
• Light therapy can reset circadian rhythms for women with severe insomnia.
• Pregnancy-safe antidepressants like sertraline (Zoloft) are often preferred over benzodiazepines when medication is needed.

Some women find relief with magnesium supplements, chamomile tea, or warm baths before bed. These aren’t magic fixes, but they’re low-risk and often effective when combined with therapy.

What Should You Do If You’re Already Taking Benzodiazepines?

If you’re pregnant and currently taking a benzodiazepine, here’s what to do:

1. Don’t stop abruptly. Sudden withdrawal can harm you and your baby.
2. Call your OB-GYN and psychiatrist. Schedule a joint appointment to review your meds.
3. Ask about tapering. A slow, controlled reduction over weeks or months is safest.
4. Start non-drug therapies now. CBT, sleep hygiene, and relaxation techniques can fill the gap.
5. Track your symptoms. Keep a journal of anxiety, sleep, and mood changes so your team can adjust your plan.

Many women successfully switch to safer treatments. It takes time, support, and patience-but it’s possible.

The Bottom Line

Benzodiazepines aren’t the enemy. For some women, they’re the only thing keeping them functional. But they’re not a first-line option in pregnancy-and they shouldn’t be treated like a quick fix.

The risks are small in absolute terms, but they’re real. And when you’re carrying a life, even a 1% increase in risk matters. The goal isn’t perfection-it’s making informed choices. If you need help managing anxiety or sleep, there are safer paths. Talk to your doctor. Explore alternatives. Give yourself grace.

You’re not alone. And you don’t have to choose between your mental health and your baby’s. There’s a better way-and it starts with asking the right questions.