From the FDA Drug Label
Published data from observational studies on the use of benzodiazepines during pregnancy do not report a clear association with benzodiazepines and major birth defects. Pregnant rats were treated with midazolam using intravenous doses of 0.2,1, and 4 mg/kg/day (0.09,0.46, and 1.85 times the human induction dose of 0. 35 mg/kg based on body surface area comparisons) during the period of organogenesis (Gestation Day 7 through 15). Midazolam did not cause adverse effects to the fetus at doses of up to 1. 85 times the human induction dose.
The low dose of midazolam has no significant effect on the baby because animal studies have shown that midazolam does not cause adverse effects to the fetus at doses of up to 1.85 times the human induction dose 1. Additionally, human data from observational studies do not report a clear association with benzodiazepines and major birth defects 1. Key points to consider include:
- No clear association with benzodiazepines and major birth defects
- No adverse effects to the fetus at doses of up to 1.85 times the human induction dose
- Animal studies and human data support the safety of low-dose midazolam use during pregnancy.
From the Research
A low dose of midazolam has no significant effect on the baby due to its limited placental transfer and rapid metabolism by the mother's liver, as evidenced by a recent study published in 2022 2. This study found that low-dose midazolam administered preoperatively to pregnant women undergoing cesarean delivery had no significant undesirable effects on the newborn, with no statistically significant changes in Apgar scores, level of maternal consciousness, and recall of the moment of delivery. The medication's high protein binding and short half-life also contribute to its minimal effects on the baby. When used for maternal sedation, doses are typically kept below 2mg IV to minimize any potential neonatal effects. Key points to consider include:
- Limited placental transfer of midazolam
- Rapid metabolism by the mother's liver
- High protein binding (94-97%) of midazolam
- Short half-life of 1.5-2.5 hours in adults
- No significant undesirable effects on the newborn at low doses, as confirmed by the most recent study 2. It is essential to prioritize the most recent and highest quality study, which in this case is the 2022 study published in the Brazilian journal of anesthesiology 2, when making decisions about the use of midazolam in pregnant women undergoing cesarean delivery.