Trichomoniasis infection is possible during pregnancy. It can cause premature birth, but an antibiotic prescription from a doctor can clear the infection.

Trichomoniasis (also called “trich”) is a sexually transmitted infection (STI) caused by a parasite. It affects an estimated 3.7 million people Trusted Source in the United States, making it the most common STI.

Trichomoniasis can be treated with antibiotics, with infections typically clearing up in a week. If left untreated, however, trichomoniasis can last for several months or years. Its symptoms can make sex unpleasant. But for pregnant people, it can also cause serious childbirth complications.

Read on to learn more about the symptoms, causes, risk factors, and what you should do if you think you have trichomoniasis. (Spoiler: Call your doctor ASAP.)

What you should know if you’re pregnant

Pregnant people with trichomoniasis are at higher risk of their water breaking — membranes rupturing — too early. Pregnant people are also at higher risk of delivering their babies prematurely, or before 37 weeks.

Babies of mothers with trichomoniasis are more likely to have a birth weight of less than 5 1/2 pounds. In extremely rare cases, female babies can contract the infection as they move through the birth canal.

Premature birth and low birth weight are two of the top three causes of death for babies. However, trichomoniasis can be treated with antibiotics during pregnancy, with infections clearing before you give birth.

What are the symptoms?

According to the Centers for Disease Control and Prevention (CDC), 70 to 85 percent Trusted Source of people with trichomoniasis don’t experience any symptoms.

In women, trichomoniasis can cause:

  • a fishy genital odor
  • large amounts of white, gray, or green vaginal discharge
  • genital itching
  • pain while urinating or having sex

Symptoms in men are rare, but they may experience:

  • irritation inside the penis
  • a burning sensation while urinating or after ejaculating
  • discharge from the penis

What causes trichomoniasis?

Trichomoniasis is caused by a microscopic parasite called Trichomonas vaginalis. It passes from person to person during sexual intercourse. The incubation period between exposure and infection is about 5 to 28 days.

Who is at risk?

Some people are more at risk of contracting trichomoniasis than others. Those with the greatest risk include people:

  • with multiple sexual partners
  • who have had other STIs in the past
  • who have had trichomoniasis in the past
  • who have sex without barrier methods, such as condoms

How is trichomoniasis diagnosed?

To test for trichomoniasis, a doctor will use a microscope to look for the parasite in a sample. For women, the sample source is vaginal discharge. For men, the sample source is urine.

A doctor may then run further tests on the sample to confirm the presence of the parasite. These include a culture test, nucleic acid amplification test, or rapid antigen test.

Pregnant people displaying any symptoms of a trichomoniasis infection should see their doctors right away. Since you’re not usually tested for trichomoniasis at regular OB-GYN appointments, the infection may go unnoticed and could harm your baby.

What are the complications?

Pregnant people with trichomoniasis are at greater risk of:

  • premature labor and delivery
  • having a baby with a low birth weight
  • transmitting trichomoniasis to a female baby during delivery (extremely rare)

All people with trichomoniasis may be more likely to contract HIV.

How is trichomoniasis treated?

Doctors usually treat trichomoniasis with antibiotics. One of two antibiotics is typically used: metronidazole (Flagyl) or tinidazole (Tindamax). You and your partner will both need treatment. Also, you both must avoid sexual intercourse until the trichomoniasis infection clears up.

You should not consume alcohol for 24 hours after taking metronidazole or 72 hours after taking tinidazole. It can lead to severe nausea and vomiting.

What is the outlook for trichomoniasis

After treatment, it usually takes about a week for a trichomoniasis infection to clear up. Most people make a full recovery.

How can you prevent trichomoniasis?

Like all STIs, the only way to fully prevent trichomoniasis is to abstain from sex.

People who are sexually active can decrease their risks of transmission by making sure barrier methods — particularly condoms — are used correctly every time during sex.

You’ll also want to wash any sex toys thoroughly after use.

You may also consider getting tested for STIs before exchanging bodily fluids with any partner.