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

When you’re pregnant and struggling with severe anxiety or insomnia, the pressure to find relief is real. Many women turn to benzodiazepines-medications like lorazepam, alprazolam, or diazepam-because they work quickly and effectively. But what happens when you’re carrying a baby? The answer isn’t simple. While these drugs help manage symptoms, growing evidence suggests they might also raise the risk of serious birth defects. This isn’t scare tactics. It’s science. And if you’re pregnant or planning to be, you need to know what the data actually says.

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

Benzodiazepines are a class of drugs first developed in the 1950s. They calm the nervous system, reduce anxiety, help with sleep, and can prevent seizures. For some women, these effects are lifesaving. 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. Why? Because anxiety and insomnia affect roughly 1 in 6 women of childbearing age. When therapy or lifestyle changes don’t cut it, doctors sometimes reach for a benzodiazepine.

But here’s the catch: these drugs cross the placenta. That means whatever you take, your baby takes too. And because fetal organs are forming in the first trimester, that’s when exposure is most risky. The developing brain, heart, and facial structures are especially sensitive to chemical disruptions.

What Birth Defects Are Linked to Benzodiazepines?

Not all birth defects are equally likely. The biggest red flags come from large studies tracking hundreds of thousands of pregnancies.

• Dandy-Walker malformation: A rare but serious brain defect where part of the cerebellum doesn’t form properly. One study found a threefold increase in risk with benzodiazepine exposure.
• Anophthalmia or microphthalmia: Missing or underdeveloped eyes. This was strongly linked to alprazolam-the brand-name drug Xanax. The risk was four times higher in women who took it during early pregnancy.
• Esophageal atresia: A condition where the esophagus doesn’t connect properly to the stomach. Again, alprazolam was the main driver of this risk.
• Heart defects: Particularly structural problems like pulmonary valve stenosis. Lorazepam (Ativan) showed a clear association here.

These aren’t common. But they’re severe. For every 1,000 women taking benzodiazepines in the first trimester, about 8 more babies will have a major birth defect compared to those who don’t. For heart defects, that number jumps to 14 extra cases per 1,000 pregnancies.

It’s not all benzodiazepines, either. Alprazolam stands out in multiple studies as the highest-risk agent. Diazepam and lorazepam show more mixed results, but still carry risk. Clonazepam? Data is limited, but caution is still advised.

What About Other Pregnancy Risks?

Birth defects aren’t the only concern. Benzodiazepines are tied to a range of other complications:

• Miscarriage: Risk increases by about 85% when taken during pregnancy.
• Preterm birth: Babies born before 37 weeks are more common in exposed pregnancies.
• Low birth weight: Babies tend to weigh less, even when born at full term.
• Neonatal withdrawal: Babies born to mothers who took benzodiazepines late in pregnancy can have jitteriness, poor feeding, breathing problems, or seizures in the first days after birth.
• Ectopic pregnancy: Even taking these drugs in the 90 days before conception raises the risk.

These outcomes aren’t just statistics. They mean longer hospital stays, NICU admissions, and sometimes lifelong care needs.

Why Do Some Studies Say There’s No Risk?

You might have seen headlines claiming benzodiazepines are safe in pregnancy. That’s because not all studies agree. One 2023 study from the British Journal of Clinical Pharmacology found no link to birth defects. So which one do you believe?

The difference lies in study design. Many early studies didn’t account for confounding by indication. That means: women taking benzodiazepines often have severe anxiety, depression, or other mental health conditions-and those conditions themselves can increase pregnancy risks. So is it the drug, or the illness behind it?

The most reliable studies, like the 2022 PLOS Medicine analysis of 3.1 million pregnancies, used advanced methods to separate drug effects from underlying illness. They even ran negative control tests-looking at outcomes that shouldn’t be affected by the drug-and found no false signals. That strengthens the case that the risks are real.

Plus, the PLOS Medicine study had over 10 times more exposed pregnancies than all previous studies combined. That kind of power matters.

What Do Medical Guidelines Say?

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

• ACOG (American College of Obstetricians and Gynecologists): Says benzodiazepines “may be used cautiously for short-term treatment,” but should be avoided in the first trimester.
• American Psychiatric Association: Recommends case-by-case decisions, with special attention to the drug, dose, and timing.
• Canadian Clinical Practice Guidelines: States benzodiazepines “should generally be avoided during pregnancy,” especially in the first trimester.
• FDA: Classifies all benzodiazepines as Category D-meaning there’s proven risk to the fetus.
• European Medicines Agency: Recommends avoiding them in the first trimester unless absolutely necessary.

There’s no blanket “safe” option. But the consensus is strong: if you don’t need it, don’t take it.

What Are the Alternatives?

If you’re pregnant and anxious or struggling to sleep, you’re not out of options.

• Cognitive Behavioral Therapy (CBT): Proven to work as well as medication for anxiety and insomnia during pregnancy. No side effects. No risk to the baby.
• Mindfulness and meditation: Studies show these reduce cortisol levels and improve sleep quality.
• Exercise: Even 30 minutes of walking a day lowers anxiety and improves mood.
• Support groups: Talking to other pregnant women with similar struggles reduces isolation and stress.
• SSRIs (like sertraline): If you need medication, some antidepressants are better studied and carry lower risks than benzodiazepines. Sertraline is often the first choice.

And yes-these alternatives take time. They’re not a quick fix. But they’re safer. And they build skills you’ll use long after your baby is born.

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

If you’re pregnant and currently on a benzodiazepine, do not stop cold turkey. Sudden withdrawal can trigger seizures, extreme anxiety, or even harm your baby.

Instead:

1. Call your OB-GYN or psychiatrist right away.
2. Don’t change your dose without professional guidance.
3. Ask about tapering off slowly-over weeks or months, depending on your dose and how long you’ve been taking it.
4. Start non-drug therapies now. Even small steps help.
5. Keep track of your symptoms. Write down when you feel anxious or can’t sleep. That helps your provider adjust your plan.

Some women need to stay on medication. If your anxiety is so severe it stops you from eating, sleeping, or caring for yourself, the risks of untreated illness may outweigh the risks of the drug. That’s a decision you make with your doctor-not alone, not on the internet.

Bottom Line: Weighing Risk and Reality

Let’s be honest: no medication is 100% safe in pregnancy. But benzodiazepines are among the highest-risk classes. The data is clearer now than ever. For most women, the benefits don’t outweigh the potential harm.

That doesn’t mean you’re failing if you’ve taken them. It doesn’t mean you’re a bad mom. It just means you need better tools.

The goal isn’t perfection. It’s safety. And safety means choosing options with the least risk to your baby-while still taking care of your mental health.

If you’re pregnant and anxious, you’re not alone. And you don’t have to suffer-or risk your baby’s health-to find relief. There are safer paths. You just need the right support to find them.