Lorazepam is not considered safe during pregnancy, though the risks vary depending on when and how long it’s used. The FDA labeling advises that use during pregnancy “should be avoided,” and the American College of Obstetricians and Gynecologists (ACOG) recommends benzodiazepines be avoided or prescribed only sparingly during the perinatal period. That said, the absolute risk increases are relatively small, and some situations call for short-term use when safer alternatives haven’t worked.
How Lorazepam Reaches the Baby
Lorazepam crosses the placenta. Blood samples taken from umbilical cords confirm that both the drug and its breakdown products reach the fetus. This means any dose a pregnant person takes will also expose the developing baby, which is why timing, duration, and dosage all matter when weighing the risks.
First Trimester: Malformation Risk
The biggest concern with early pregnancy exposure is a modest increase in birth defects. A large population-based study in South Korea found that pregnancies exposed to benzodiazepines in the first trimester had an overall malformation rate of about 65 per 1,000, compared to 51 per 1,000 in unexposed pregnancies. That’s an absolute increase of roughly 14 extra cases per 1,000 pregnancies.
Heart defects drove much of the difference: 39 per 1,000 in exposed pregnancies versus 27 per 1,000 in unexposed ones. To put this in perspective, the vast majority of exposed pregnancies (about 93.5%) still resulted in no detected malformation. The risk is real but small in absolute terms.
Miscarriage Risk
Benzodiazepine use in early pregnancy is also linked to a higher rate of miscarriage. A 2024 meta-analysis pooling multiple studies found that benzodiazepine exposure was associated with a 68% increased risk of miscarriage overall. When researchers looked at lorazepam specifically, the pooled odds ratio was 1.48, meaning roughly a 48% higher risk compared to non-use. Every individual study included in the analysis found a statistically significant increase. These numbers come from observational data, so they can’t fully separate the effect of the drug from the effect of the underlying anxiety or other factors that led to the prescription, but the signal is consistent across studies.
Third Trimester: Effects on the Newborn
Using lorazepam late in pregnancy carries its own set of risks, centered on how the baby transitions after birth. Two overlapping conditions can occur.
Floppy infant syndrome appears immediately after delivery. Babies may have noticeably low muscle tone, weak reflexes, and difficulty feeding. Symptoms typically resolve within hours to days.
Neonatal withdrawal tends to show up 8 to 48 hours after birth and can last much longer, sometimes persisting for weeks to months. Symptoms include tremors, irritability, high-pitched crying, feeding difficulties, sleep disturbances, and occasionally respiratory distress. In most infants these symptoms are mild (sleep problems being the most common). Severe symptoms like seizures are rare. ACOG notes that benzodiazepine exposure during pregnancy has been associated with neonatal sedation, decreased muscle tone, respiratory compromise, and NICU admission.
Long-Term Effects on Child Development
One of the most reassuring findings comes from a large cohort study of over 1.5 million children published in JAMA Network Open. Initial analyses suggested a link between prenatal benzodiazepine exposure and neurodevelopmental conditions like autism and ADHD. But when researchers compared siblings (where one was exposed in utero and one was not), the association disappeared entirely. This sibling comparison controlled for shared genetics and family environment, and it held true regardless of which trimester the exposure occurred in.
The researchers concluded that the previously reported links between benzodiazepines and neurodevelopmental disorders were likely explained by the mother’s own genetic and mental health profile, not by the drug itself. While this doesn’t rule out subtler effects that studies haven’t captured, it’s meaningful evidence that prenatal exposure probably doesn’t raise the risk of ADHD or autism.
When Doctors Still Prescribe It
ACOG’s position is nuanced. The strong recommendation is to avoid benzodiazepines or use them sparingly, but the guidelines acknowledge situations where short-term use makes sense. The most common scenario: a person with moderate to severe anxiety starts an antidepressant (like an SSRI), and lorazepam is prescribed as a bridge for 2 to 4 weeks until the antidepressant takes effect. Once it does, the lorazepam is tapered gradually, typically reducing the dose by 25 to 50% per week. Stopping abruptly is not recommended because of withdrawal risk for the mother.
Lorazepam also has a specific role in emergencies. For postpartum psychosis, it’s considered part of the first-line treatment alongside antipsychotic medication while waiting for psychiatric evaluation. And for pregnant patients with liver disease or preeclampsia, lorazepam is actually preferred over other benzodiazepines because of the way it’s processed in the body.
Alternatives that doctors typically try first include SSRIs, SNRIs, psychotherapy (particularly cognitive behavioral therapy, which has a strong evidence base for anxiety), and for acute insomnia, hydroxyzine. Alprazolam is specifically flagged by ACOG as a worse choice than lorazepam due to its higher addiction potential and more severe withdrawal profile.
Lorazepam and Breastfeeding
The picture is more favorable for nursing mothers. Lorazepam passes into breast milk at low levels, and its relatively short duration of action means it doesn’t accumulate the way longer-acting benzodiazepines can. At a maternal dose of 2.5 mg twice daily, the estimated infant exposure through breast milk is about 8.5% of the weight-adjusted maternal dose, which is considered low.
In a follow-up study of 64 mothers who took lorazepam while breastfeeding, none reported sedation in their infants. One isolated case of infant sedation was reported in a mother taking lorazepam alongside an antipsychotic, and it resolved when lorazepam was stopped. The Drugs and Lactation Database rates lorazepam as possible to use during breastfeeding, with the recommendation to monitor the baby for sedation, poor feeding, and slow weight gain.
Putting the Risks in Context
If you took lorazepam before realizing you were pregnant, the absolute risk increases are small. The overall malformation rate goes from about 5.1% to about 6.5%, and most exposed pregnancies result in healthy babies. The miscarriage risk is more concerning but also difficult to fully separate from the anxiety or insomnia that prompted the prescription in the first place.
If you’re currently pregnant and taking lorazepam, the key variables are how far along you are, how much you’re taking, and whether alternatives could work for your situation. Stopping abruptly on your own carries risks too, both from withdrawal and from untreated anxiety or panic, which themselves can affect pregnancy outcomes. The decision is one to make with a provider who can weigh your specific mental health needs against the known risks of continued use.