Trichomoniasis during pregnancy

By trimester

Weeks 1–13

1st trimester

Symptoms such as discharge, irritation, burning, or painful urination overlap with other vaginal and urinary conditions. Laboratory confirmation matters, and available metronidazole pregnancy data do not show an increased overall birth-defect risk.

Weeks 14–27

2nd trimester

Symptomatic infection should be tested and managed rather than waiting for later pregnancy. Discuss the full metronidazole regimen, adherence, partner care, other STI testing, and the follow-up plan with the obstetric clinician.

Weeks 28–birth

3rd trimester

Complete clinician-directed care and partner management before birth when possible. Trichomoniasis is associated with preterm birth and membrane rupture in observational studies, but an association does not show that infection caused an individual outcome.

What does the evidence show for trichomoniasis?

• CDC recommends laboratory testing and metronidazole care for symptomatic pregnant patients regardless of gestational age. Routine screening of asymptomatic pregnant patients has not been shown to provide benefit, so symptoms and individual risk guide testing. 1
• Most people with trichomoniasis have no symptoms, while others develop genital irritation, painful urination, or vaginal discharge. Symptoms alone cannot confirm the infection; a laboratory test is required. 2
• MotherToBaby reports no increased birth-defect signal across more than 5,000 metronidazole-exposed pregnancies and no increased miscarriage signal in a larger early-pregnancy exposure dataset. These observational data cannot rule out every rare outcome or remove individual prescribing considerations. 3
• A systematic review and meta-analysis of 19 studies found trichomoniasis associated with preterm delivery, prelabor membrane rupture, and low birth weight. Study heterogeneity and observational designs mean these results do not establish causation or a certain outcome for one pregnancy. 4
• CDC recommends concurrent care for all current sex partners, abstinence until all partners complete their regimens and symptoms resolve, testing for HIV, syphilis, gonorrhea, and chlamydia, and repeat testing for women about three months later because reinfection is common. 1

When should I call my provider about trichomoniasis?

Seek urgent maternity care for fever with severe pelvic or abdominal pain, heavy bleeding, leaking fluid, regular painful contractions before term, fainting, or inability to keep fluids down. Contact the obstetric clinician promptly for a medication reaction, worsening symptoms, recurrent discharge after completing the regimen, or known re-exposure from a partner. Trust your read on your own body. If something feels off beyond the list above, please consult your healthcare provider rather than waiting it out.