Is doxylamine + vitamin B6 safe during pregnancy?

What does the evidence say about doxylamine + vitamin B6 during pregnancy?

1. Studies covering hundreds of thousands of pregnancies exposed to doxylamine and B6 together have not found an increased risk of birth defects. 1
2. Doxylamine plus B6 is the first medication ACOG recommends trying once non-drug measures for nausea aren't enough on their own. 2
3. The over-the-counter version is Unisom SleepTabs (doxylamine succinate 25 mg) paired with 10 to 25 mg of vitamin B6, and Unisom SleepGels are a different product made with diphenhydramine, so they're not a substitute. 3
4. Drowsiness is the most common side effect, which is why many dosing plans put more of the dose in the evening, with a smaller morning dose added only if daytime nausea needs it too. 1

Is doxylamine + vitamin B6 safe in each trimester?

• First trimester. This is when most people start using it, since nausea and vomiting peak in the first trimester. A typical approach splits the 25 mg Unisom tablet with 10 to 25 mg of B6, adjusting the dose until it helps.
• Second trimester. If nausea continues into the second trimester, keep using the lowest dose that helps. Your provider can guide you on tapering down once symptoms ease.
• Third trimester. Some people still need it occasionally in the third trimester if nausea comes back. Keep in mind doxylamine can make you sleepy, which matters when your energy is already up and down late in pregnancy.