Is Klonopin (Clonazepam) Safe During Pregnancy?

What does the evidence say about klonopin during pregnancy?

1. Limited studies looking at clonazepam used alone during pregnancy have not found an increased chance of major birth defects, though the same research noted a possible link to preterm birth and lower birth weight. 1
2. Clonazepam use close to delivery can cause temporary symptoms in newborns, including trouble breathing, bluish skin tone from low oxygen, poor circulation, and low muscle tone known as floppy baby syndrome, and some babies need extra monitoring after birth. 2
3. Clonazepam passes into breastmilk in small amounts and can occasionally cause sedation in a breastfed infant, especially when combined with other sedating medications, so clinicians recommend watching the baby for drowsiness and steady weight gain and sometimes favor a shorter-acting benzodiazepine instead. 3
4. Research on benzodiazepine-class medications found that the odds of complications such as preterm birth and stillbirth were higher with exposure in the second half of pregnancy than with exposure earlier on, a pattern researchers link to increased placental transfer later in pregnancy. 4
5. Benzodiazepines were formerly grouped under FDA pregnancy category D, meaning some evidence of fetal risk exists but the benefit may still support use in certain pregnancies, and guidance calls for tapering under medical supervision rather than stopping suddenly, since the same class has been linked to neonatal low muscle tone and withdrawal. 5

Is klonopin safe in each trimester?

• First trimester. Limited human data on clonazepam used alone in pregnancy has not shown a higher rate of major birth defects. That reassurance is specific to clonazepam, not the whole benzodiazepine class: two other benzodiazepines, diazepam and chlordiazepoxide, have been linked to a small increase in malformations such as cleft palate in some studies, part of why clinicians approach first-trimester benzodiazepine use with added caution generally. One study also noted a higher chance of pregnancy loss at doses above 4 mg a day, though that link is unconfirmed. Bring your exact dose to this conversation with your prescriber.
• Second trimester. Anxiety or seizure symptoms can shift in intensity as pregnancy progresses, so the second trimester is a reasonable point to check in with your prescriber about whether your current dose still fits. Research on benzodiazepines as a class has found that the odds of complications like preterm birth appear to climb further in pregnancy, which is useful context for planning ahead rather than a reason to stop on your own. If a taper ever makes sense for you, it should be gradual and supervised.
• Third trimester. Exposure close to delivery is the best-documented risk window: newborns can show temporary breathing trouble, bluish skin tone, poor circulation, and low muscle tone, sometimes called floppy baby syndrome, and some need extra monitoring after birth. Tell your delivery team and your baby's care team exactly what you take and your current dose so they know what to watch for. This is a reason for coordinated planning, not a reason to stop clonazepam abruptly on your own.