Labetalol During Pregnancy: Safety for Blood Pressure

What does the evidence say about labetalol during pregnancy?

1. Available information does not suggest that using labetalol in pregnancy raises the chance of birth defects above the general population's baseline rate of about 3%. 1
2. Research reviewed in this fact sheet indicates labetalol does not significantly increase the risk of preterm delivery, low birth weight, or stillbirth. 2
3. Babies exposed to labetalol late in pregnancy can have a temporary slowed heart rate, low blood pressure, or low blood sugar after birth; these effects typically resolve within days, though preterm infants exposed for longer may need closer monitoring. 1
4. In a real-world cohort of pregnant patients managed for a hypertensive disorder, labetalol was the most frequently prescribed antihypertensive, used in about 75% of cases overall and in nearly 82% of cases involving severe preeclampsia. 3
5. In a trial of intravenous medications for severe gestational hypertension, labetalol was dosed in escalating amounts, starting at 25 mg and increasing up to a 300 mg maximum, given every 20 minutes until blood pressure reached target, though it took longer and needed more doses on average than intravenous hydralazine in that comparison. 4

Is labetalol safe in each trimester?

• First trimester. If chronic high blood pressure is identified early, labetalol is often started as a first-choice oral medication, with your dose adjusted based on your readings.
• Second trimester. Blood pressure needs can shift as pregnancy progresses, so expect dose adjustments and more frequent checks, especially if signs of preeclampsia develop.
• Third trimester. Because babies exposed late in pregnancy can have a temporary low heart rate or blood sugar after birth, your care team will likely watch your newborn closely for the first day or two, especially with a preterm delivery.