Written by Crystal Lai, PharmD Candidate 2025 & Regina Ginzburg, Pharm.D., CDCES, BC-ADM

Benzodiazepines are a class of medications indicated for generalized anxiety disorder, seizures, and insomnia. These drugs end in “lam or pam,” such as alprazolam, lorazepam, diazepam, or clonazepam.¹ Despite their potential to cause serious adverse effects and potential for abuse, 5% of people aged 18-65 years old are prescribed a benzodiazepine.² A significant percentage of benzodiazepine users obtain their pills without a prescription, usually getting them from a friend or relative.³

Most benzodiazepines were classified in the former FDA pregnancy category as class D, meaning that there has been some evidence of human fetal risk, but in some cases, the benefits may outweigh the risks. Some were classified as class X (i.e., flurazepam, estazolam, temazepam, quazepam, and triazolam), which are contraindicated in pregnancy.¹ Benzodiazepines can cross the placenta and enter breast/chest milk.⁴ 

An increased risk of miscarriage has been associated with benzodiazepine use during pregnancy.^5,6 Recent meta-analyses and systematic reviews suggest little to no association between benzodiazepine use and congenital malformations.^7,8 Chronic use of benzodiazepines around the time of delivery, however, can cause neonatal withdrawal syndrome and possibly negatively impact neurobehavioral development.⁹ These symptoms typically resolve a few weeks to months after birth, and studies following neonates exposed to benzodiazepines in utero over several years did not show a significantly increased risk of neurological problems that could be attributed to benzodiazepine use.⁴

Although benzodiazepines can cross into breast/chest milk during lactation, some studies have determined the amount to be very little. One study found alprazolam, clonazepam, and lorazepam to have milk to plasma ratios of less than 1 and relative infant doses of less than 10%, which is considered compatible with nursing.^4,10,11 In a cohort of mothers who used benzodiazepines during lactation, only 1.6% reported adverse effects, specifically sedation, in infants.¹² Long-acting benzodiazepines should still be avoided in this case to decrease the risk of accumulation in milk, and the lowest effective dose should be used.¹¹ If the medication is to be used while the patient is nursing, they must carefully monitor the baby for adverse effects, like sedation, respiratory depression, or inability to suckle. Of note, lorazepam has been safely administered to infants.¹³

The American College of Obstetricians and Gynecologists strongly recommend against the use of benzodiazepines or to use them sparingly for treatment of moderate to severe anxiety.¹¹ They recommend benzodiazepines to be reserved if needed to manage acute symptoms while bridging with SSRIs or other appropriate medication therapy for anxiety. If they must be used, especially for a longer period of time, providers must have a discussion with the patient of risks vs benefits, and benzodiazepines should be tapered off or avoided in the third trimester, if possible. The Academy of Breastfeeding Medicine advises that individuals may safely breastfeed while taking a benzodiazepine for anxiety.¹⁴ A short-acting benzodiazepine, like lorazepam, is recommended as it is less likely to cross the placenta and into breast/chest milk, and there is less risk of addiction and withdrawal symptoms.¹¹ 

Benzodiazepines may also be used as part of general anesthesia. Midazolam is most commonly used due to its quick onset and short duration of action.15 Small amounts of midazolam can travel through the placenta, but it has not been associated with sedation in neonates.^4,16 While considered acceptable for use in pregnancy or breast/chestfeeding, caution is still advised as respiratory depression has occurred in neonates when midazolam was used prior to caesarean section procedure.⁴ Small amounts can also cross into milk, but if only given as a single dose, midazolam is unlikely to accumulate and will be undetectable in milk 4 to 7 hours after the dose. Therefore, it is reasonable to advise patients to wait at least 4 hours before resuming breast/chestfeeding.¹⁶

Benzodiazepines can have significant consequences in pregnancy, but there may be a role for those with moderate to severe anxiety if used short-term while bridging to suitable medication therapy or if needed to be used during a procedure/surgery. Preconception counseling for patients taking benzodiazepines should include a plan to taper/discontinue benzodiazepines if possible. If a benzodiazepine must be used for anxiety, choose lorazepam at the lowest possible dose; for surgery, choose midazolam.