Clobazam in Pregnancy
Clobazam should only be used during pregnancy if the potential benefit to the mother clearly justifies the potential risk to the fetus, as there are no adequate controlled studies in pregnant women and animal data show developmental toxicity at clinically relevant doses. 1
Safety Profile and Risk Assessment
The FDA drug label explicitly states that clobazam, as a benzodiazepine antiepileptic drug, carries important pregnancy-related risks 1:
Teratogenic Concerns
- No marked increase in congenital anomalies has been consistently documented with benzodiazepines as a class, though early studies suggested possible associations with cleft lip/palate 1
- More recent meta-analyses show conflicting results: cohort studies found no increased risk (OR 0.90 for major malformations), while case-control studies suggested elevated risk (OR 3.01) 1
- A 2019 network meta-analysis specifically identified a signal for increased major congenital malformations with clobazam, though statistical significance was not established and exposure numbers were small 2
- Animal studies demonstrated fetal malformations and mortality at plasma exposures below therapeutic human doses 1
Fetal and Neonatal Complications
Second and third trimester exposure carries specific risks 1:
- Decreased fetal movement and heart rate variability
- "Floppy infant syndrome" when administered near delivery: lethargy, hypothermia, hypotonia, respiratory depression, difficulty feeding (lasts up to 14 days)
- Neonatal withdrawal syndrome: hypertonia, hyperreflexia, hypoventilation, irritability, tremors, diarrhea, vomiting (can appear shortly after birth to 3 weeks postpartum and persist for months)
- Insufficient evidence exists regarding neurodevelopmental effects 1
Clinical Management Recommendations
If Clobazam Must Be Continued
Enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry by calling 1-888-233-2334 or visiting www.aedpregnancyregistry.org 1
Use the lowest effective dose for the shortest duration necessary to control seizures
Provide comprehensive counseling about fetal risks including malformations, withdrawal, and floppy infant syndrome 1
Monitor newborns closely for withdrawal symptoms and floppy infant syndrome, particularly if exposure occurred in late pregnancy 1
Important Caveats
Contraceptive efficacy may be reduced: Clobazam is a weak CYP3A4 inducer and can diminish effectiveness of hormonal contraceptives. Additional non-hormonal contraception is mandatory 1
Avoid concomitant CNS depressants and alcohol as these increase sedation risk and clobazam exposure by approximately 50% 1
Dose adjustments may be needed with CYP2C19 inhibitors (fluconazole, fluvoxamine, omeprazole) as these increase exposure to the active metabolite N-desmethylclobazam 1
Risk-Benefit Context
The decision to use clobazam in pregnancy must weigh the maternal risk of uncontrolled seizures (which can cause maternal and fetal harm) against the fetal risks outlined above. For women with epilepsy requiring treatment, pregnancy-compatible alternatives should be strongly considered first. The 2025 EULAR guidelines, while focused on rheumatologic conditions, do not list benzodiazepines among pregnancy-compatible medications 3, and the 2020 ACR guidelines make no specific recommendations for benzodiazepines in pregnancy 4.
The signal for increased malformation risk with clobazam specifically 2, combined with well-documented neonatal complications 1, makes this a high-risk medication that should be avoided when safer alternatives exist for seizure control.