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

If you’re pregnant or planning to be, and you’ve been taking benzodiazepines for anxiety or insomnia, you’re not alone. But you’re also facing a question that keeps many women awake at night: Is it safe? The answer isn’t simple. It’s not a simple yes or no. It’s about weighing real, documented risks against the very real dangers of untreated anxiety or severe sleep loss during pregnancy.

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

Benzodiazepines are a class of drugs that calm the nervous system. Common ones include lorazepam (Ativan), alprazolam (Xanax), diazepam (Valium), and clonazepam (Klonopin). They work fast - often within an hour - to reduce anxiety, stop panic attacks, and help with sleep. For some women, these medications are the only thing that brings relief from debilitating panic or chronic insomnia during pregnancy.

But here’s the catch: benzodiazepines cross the placenta. That means what you take, your baby takes too. The drug doesn’t just sit in your bloodstream - it builds up in fetal tissue. And because the developing brain and organs are so sensitive, even small amounts can have lasting effects.

The Evidence: What Do Large Studies Actually Show?

Two major studies from 2022 and 2024 changed how doctors think about benzodiazepines in pregnancy. The first, published in PLOS Medicine, looked at over 3 million pregnancies in South Korea. It found a small but real increase in overall birth defects - about 8 extra cases per 1,000 pregnancies exposed in the first trimester. The risk for heart defects was even higher: about 14 extra cases per 1,000.

That might sound small. But when you’re expecting, even one extra case matters. And it’s not just about heart defects. The same study found a dose-response pattern: the more you take each day, the higher the risk. Taking more than 2.5 mg of lorazepam-equivalent daily raised the risk noticeably.

Another study, from the CDC’s National Birth Defects Prevention Study, looked at over 11,000 pregnancies in the U.S. and found something more specific - and more alarming. Women who took alprazolam during the first trimester had nearly four times the risk of anophthalmia or microphthalmia (missing or underdeveloped eyes). They also had nearly three times the risk of esophageal atresia, a serious condition where the tube connecting the mouth to the stomach doesn’t form properly.

Lorazepam was linked to pulmonary valve stenosis - a narrowing of the heart’s main artery. And Dandy-Walker malformation, a rare brain defect, was more than three times more common in babies exposed to benzodiazepines.

Not every study agrees. One 2023 study in the British Journal of Clinical Pharmacology found no clear link. But that study had far fewer women taking these drugs. The larger, more rigorous studies - especially the 2024 JAMA Psychiatry analysis - suggest the risk isn’t just noise. It’s real.

It’s Not Just Birth Defects

Even if your baby is born without a physical defect, benzodiazepines can still affect them. Studies show a higher risk of:

• Miscarriage - up to 85% higher risk after adjusting for other factors
• Preterm birth
• Low birth weight
• Small for gestational age
• Low Apgar scores at 5 minutes
• Neonatal intensive care unit (NICU) admission

And it’s not just during pregnancy. If you’re taking benzodiazepines near delivery, your newborn might be born with withdrawal symptoms: jitteriness, poor feeding, breathing problems, or seizures. These aren’t rare. They happen often enough that hospitals now watch newborns closely if the mother took these drugs late in pregnancy.

What About Alprazolam? Is It Worse?

Yes. Alprazolam stands out. Multiple studies point to it as the most concerning benzodiazepine in pregnancy. It’s linked to the highest risks for eye defects and esophageal problems. That doesn’t mean other benzodiazepines are safe - but if you’re on alprazolam and pregnant, your doctor should be especially cautious.

Some women are switched to diazepam or lorazepam because they’re thought to be slightly less risky. But even those carry risks. No benzodiazepine is proven safe in pregnancy. The idea that one is "safer" is based on limited data, not proof.

What Do Experts Say?

The American College of Obstetricians and Gynecologists (ACOG) says benzodiazepines "may be used cautiously for short-term treatment" - but only if benefits clearly outweigh risks. And they strongly recommend avoiding them in the first trimester, when organs are forming.

The FDA classifies benzodiazepines as Pregnancy Category D - meaning there’s clear evidence of fetal risk. The European Medicines Agency and Canadian guidelines are even stricter: avoid them in pregnancy unless absolutely necessary.

The bottom line? These drugs aren’t first-line treatment anymore. They’re a last resort - and only if nothing else works.

What Are the Alternatives?

If you’re struggling with anxiety or sleep during pregnancy, you have options - and many are safer.

• Cognitive Behavioral Therapy (CBT): Proven to work as well as medication for anxiety and insomnia in pregnancy. No side effects. No risk to the baby.
• Support groups: Talking with other pregnant women who understand can reduce isolation and stress.
• Mindfulness and meditation: Studies show even 10 minutes a day can lower cortisol and improve sleep.
• Exercise: Walking, prenatal yoga, swimming - all help regulate mood and sleep cycles.
• SSRIs: For severe anxiety, some antidepressants like sertraline are considered safer than benzodiazepines in pregnancy. They’re not risk-free, but their risk profile is better understood.

Many women stop benzodiazepines cold turkey. That’s dangerous. Withdrawal can cause seizures, extreme anxiety, or rebound insomnia - which can harm both you and your baby. If you want to stop, work with your doctor to taper slowly, over weeks or months.

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

Don’t panic. Don’t stop suddenly. Do this:

1. Call your OB-GYN or midwife. Tell them exactly what you’re taking, how much, and for how long.
2. Ask for a referral to a perinatal psychiatrist - they specialize in mental health during pregnancy.
3. Discuss your options: Can you switch to a safer medication? Can you start therapy? Can you reduce your dose gradually?
4. If you’re in the first trimester, focus on minimizing exposure. Avoid new prescriptions if possible.
5. If you’re in the third trimester, prepare for possible neonatal withdrawal. Talk to your pediatrician and delivery team.

Many women successfully stop benzodiazepines during pregnancy - with support. You don’t have to do it alone.

The Bigger Picture: Your Mental Health Matters Too

It’s easy to focus only on birth defects. But untreated anxiety and insomnia during pregnancy carry their own risks - including preeclampsia, preterm birth, and postpartum depression. Sometimes, the risk of not treating your mental health is higher than the risk of medication.

The goal isn’t to scare you. It’s to help you make an informed choice. If you’re in crisis - if you’re having panic attacks every day, or can’t sleep for weeks - you deserve help. The right help. Not just any pill. The right treatment plan.

That might mean therapy. It might mean a different medication. It might mean a combination of both. But it doesn’t have to mean continuing a drug with known risks when safer options exist.

Final Thoughts

Benzodiazepines aren’t banned in pregnancy. But they’re no longer the go-to solution. The evidence is clear: they carry real risks - especially in the first trimester, especially at higher doses, especially alprazolam.

But your mental health matters too. You’re not weak for needing help. You’re not selfish for wanting to feel better. The best thing you can do is talk to your doctor - honestly, without shame - and work together to find the safest path forward.

There’s no perfect choice. But there is a thoughtful one. And you deserve that.