Metronidazole in Pregnancy — Is It Safe?
Last reviewed: · Source: US FDA drug label database
This page contains affiliate links. We may earn a commission if you purchase through them, at no extra cost to you.
Metronidazole is avoided in the first trimester by convention, but can be used later in pregnancy when needed — bacterial vaginosis must be treated.
Confirm parentage with confidence — order a DNA test at Paternity Lab →
Is it safe to take Metronidazole with Pregnancy?
Metronidazole is used to treat bacterial vaginosis (BV), C. difficile, dental infections, and protozoal infections. In the first trimester, it is generally avoided by convention — early studies suggested teratogenicity that has not been confirmed in large modern analyses, but caution remains. From the second trimester, it is considered acceptable when clinically needed. Untreated BV in pregnancy is associated with preterm labour, making treatment important. Remember: even in pregnancy, avoid all alcohol while taking metronidazole and for 48 hours after.
How do Metronidazole and Pregnancy interact?
Metronidazole's early teratogenicity signal was based on animal studies (mutagenicity at very high doses) not confirmed in human epidemiological data. Modern registry studies covering thousands of first-trimester exposures have not found a consistent pattern of birth defects. It remains off the 'preferred first trimester' list by caution rather than confirmed evidence of harm.
Data sourced from the US Food and Drug Administration (FDA) drug label database: OpenFDA metronidazole label; UKTIS metronidazole-in-pregnancy review.
As an Amazon Associate we earn from qualifying purchases. We also earn commission from other retail partners. Links below are affiliate links.
Supports bump, back and hips for a more comfortable night's sleep throughout pregnancy.
Check Price →Comprehensive pregnancy supplement with folic acid, iron and vitamin D — NHS recommended nutrients.
Check Price →Week-by-week guide to pregnancy, birth and the first weeks of parenthood.
Check Price →Who should be careful?
Women in the first trimester for whom an alternative antibiotic covers the indication; women with BV at any trimester (treat it — don't leave BV untreated in pregnancy).
What if I've already taken Metronidazole and Pregnancy?
If you took metronidazole in the first trimester — the modern evidence is largely reassuring. Document it with your midwife. No alcohol during the course and for 48 hours after.
Managing multiple medications day to day? AutomationHomeGuide covers smart medication reminders and other home tech that helps.
Confirming a pregnancy raises questions medication alone can't answer.
Paternity Lab offers fast, confidential DNA testing with results in as little as 24 hours.
Order a DNA test at Paternity Lab →Affiliate link — we may earn a commission at no extra cost to you.
This page contains affiliate links. We may earn a commission if you purchase through them, at no extra cost to you.
CJ — PATERNITY LABPaternity Lab — fast, confidential DNA testing. Results in as little as 24 hours. Discreet delivery to your door. Court-admissible results also available.
Order a DNA test at Paternity Lab →This page contains affiliate links. We may earn a commission if you purchase through them, at no extra cost to you.
CJ — LAWDEPOTLawDepot — legal documents made simple. Child travel consent forms, wills, power of attorney and more — fill in online, print immediately.
Create legal document at LawDepot →Curious what a DNA test can reveal beyond parentage? 247GeneticCheck covers health and ancestry testing alongside DNA verification.
Frequently Asked Questions
Can I take metronidazole while pregnant?
After the first trimester, yes — it's used for BV, which must be treated in pregnancy. First-trimester use is cautious but modern data are largely reassuring.
Can metronidazole cause miscarriage?
Early studies suggested concerns not confirmed in modern large analyses. Current evidence does not establish metronidazole as a cause of miscarriage.
I was given metronidazole for BV in pregnancy — is it safe?
Yes — treating BV in pregnancy is important to reduce preterm labour risk. Complete the course and remember no alcohol during treatment.
Why avoid alcohol with metronidazole in pregnancy?
Metronidazole causes a severe disulfiram-like reaction with alcohol (vomiting, racing heart). This applies in pregnancy exactly as it does normally. Avoid all alcohol during the course and for 48 hours after.