Last updated: April 2026
Finding out you have a sexually transmitted infection during pregnancy is the kind of news that sends most people straight to Google at midnight. If that's where you are right now, the most important thing to know upfront is this: trichomoniasis during pregnancy is treatable, and catching it early makes a real difference. The risks are real: preterm birth, low birth weight, premature rupture of membranes, but so is the treatment. What follows is a complete, honest breakdown of what trich actually does during pregnancy, what the symptoms look like (and why most people don't have any), when to test, and how treatment works when you're pregnant.
Trichomoniasis during pregnancy is common enough to warrant serious attention. According to the CDC, an estimated 2.6 million people in the United States are currently infected with Trichomonas vaginalis at any given time, and because it's not a reportable disease, that number is almost certainly an undercount. Among pregnant women specifically, untreated trich is associated with a 1.4-times greater likelihood of preterm birth and premature rupture of membranes, and with infants who are small for gestational age. Those numbers aren't meant to alarm; they're meant to make clear why testing matters, and why doing nothing is not actually the safe option.
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What Is Trichomoniasis and Why Does It Matter More During Pregnancy?
Trichomoniasis is caused by Trichomonas vaginalis, a single-celled parasite that infects the genital tract. It's spread through sexual contact, vaginal, oral, or anal, and unlike many STIs, it doesn't need a cut or break in skin to establish an infection. The parasite thrives in the warm, moist environment of the vagina, urethra, and surrounding tissue, where it can quietly reproduce for weeks or months without triggering any obvious symptoms.
In the general population, trich is uncomfortable but manageable. During pregnancy, the stakes shift. Pregnancy changes the vaginal environment, pH, mucus composition, and immune modulation in ways that can make the body more vulnerable to the inflammatory effects of T. vaginalis. The parasite triggers an immune response in the cervicovaginal tissue that, in a pregnant woman, can reach the membranes surrounding the fetus. That inflammatory cascade is what researchers believe drives the connection between trich and adverse pregnancy outcomes. It's not that the parasite crosses into the womb directly; it's that the body's response to it creates conditions that put the pregnancy at risk.
This is also why trichomoniasis during pregnancy sits in a different category than, say, a mild yeast infection. The discomfort might feel similar. The discharge might look similar. But the underlying mechanism, and the potential consequences, are categorically different, which is why testing and treatment, not watchful waiting, is the right call.
A 2025 paper published in the American Journal of Obstetrics and Gynecology highlighted a growing concern among researchers: trichomoniasis remains unmonitored at the federal level because it's not a reportable disease, meaning there's no national tracking system capturing its true impact during pregnancy. The authors called for trichomoniasis to be made reportable, specifically because of its association with adverse pregnancy outcomes and the fact that most infected women are asymptomatic. Until that changes, the burden of detection falls squarely on individual awareness and on testing.
Even if you're not pregnant, regular testing and safe sex are a big part of your health, and knowing your status can make a huge difference in future pregnancies. For more on this topic, read this article: When to Get Tested for Trichomoniasis After a Risky Hookup
Trichomoniasis Symptoms During Pregnancy, and Why Most Women Won't Have Any
Here's the frustrating reality: somewhere between 70% and 85% of people infected with trichomoniasis have no symptoms at all. That number holds during pregnancy. Which means the most common experience of trich in pregnancy is not discharge, not itching, not odor, it's nothing. No signal, no warning, no reason to suspect anything is wrong.
When symptoms do appear, they typically include a thin or frothy vaginal discharge that ranges in color from clear to white, yellowish, or greenish, often with a distinctive fishy or musty odor. Vaginal itching, burning, or soreness is common, as is discomfort during urination or intercourse. Some women notice redness or swelling around the vaginal opening. These symptoms can come and go, present one week, absent the next, which makes it easy to attribute them to normal pregnancy changes and move on.
That's the trap. Pregnancy produces its own version of most of these symptoms. Increased vaginal discharge is entirely normal during pregnancy. So is some mild discomfort. The overlap between normal pregnancy changes and trichomoniasis symptoms is significant enough that symptoms alone are genuinely unreliable as a diagnostic tool. The CDC is unambiguous on this point: trichomoniasis cannot be diagnosed from symptoms alone. A test is always required for a confirmed diagnosis.
The practical takeaway from that table is simple: if your discharge changes character, new odor, new color, bubbling texture, accompanied by itching or burning, that's worth investigating, not dismissing. But even if you feel completely fine, if you have reason to believe you may have been exposed to a sexually transmitted infection during pregnancy, testing is the only way to know for certain.
For a more detailed breakdown of what trichomoniasis symptoms during pregnancy look and feel like, and how they progress across trimesters, see our companion article: Trichomoniasis Symptoms During Pregnancy, or Why You Probably Won't Have Any.
The Real Risks: What Untreated Trichomoniasis Does During Pregnancy
The risks of untreated trichomoniasis during pregnancy are specific, documented, and serious enough to take seriously, but they're also not inevitable, and understanding exactly what they are makes it easier to put them in context rather than spiral.
The three most well-documented adverse outcomes associated with trichomoniasis in pregnancy are preterm delivery, premature rupture of membranes (PROM), and low birth weight. A systematic review and meta-analysis published in PMC, one of the most comprehensive analyses of the available evidence, confirmed that trichomoniasis in pregnant women is associated with all three outcomes. According to CDC STI treatment guidelines, T. vaginalis has been reported to be associated with a 1.4-times greater likelihood of preterm birth and premature rupture of membranes, and with infants who are small for gestational age.
Premature rupture of membranes, the early breaking of the amniotic sac before labor begins, is worth understanding mechanistically. The leading theory is that T. vaginalis triggers an inflammatory response in the cervicovaginal tissue that produces cytokines and prostaglandins, compounds that are also involved in the normal onset of labor. When this inflammatory signaling happens prematurely, it can weaken the membranes of the amniotic sac and initiate contractions before the pregnancy has reached term. This is why researchers now classify trich alongside other infections that are capable of crossing the biological threshold between an STI and a pregnancy complication.
The risk to the newborn is real but rare. Perinatal transmission, the baby acquiring the infection during birth, is uncommon, but it does happen. When it does, it most often causes respiratory infection or, in female newborns, vaginal colonization. These cases are typically mild and resolve once the infant's exposure to maternal hormones diminishes. More serious neonatal cases, including respiratory distress and disseminated infection, have been documented but are rare.
There is one additional layer of risk that often goes undiscussed: trichomoniasis increases susceptibility to HIV. The inflammation it causes in the genital tract creates what immunologists call a portal of entry, the tissue is more permeable, the local immune environment is disrupted, and both acquisition and transmission of HIV become significantly more likely. For pregnant women, this matters beyond their own health: HIV during pregnancy carries its own set of severe risks for the developing fetus.
For a deep dive into the preterm birth and miscarriage risk specifically, see: Can Trichomoniasis Cause a Miscarriage or Preterm Birth?
How Trichomoniasis Is Transmitted During Pregnancy, and Who Is Most at Risk
Trichomoniasis is a sexually transmitted infection, which means it spreads through sexual contact with a partner who is infected. Vaginal sex is the most common route of transmission. The parasite can also spread through oral sex and anal sex, though these routes are less efficient. Importantly, T. vaginalis does not survive long outside the body; it cannot spread through shared toilets, towels, or casual contact in the way that some other pathogens can.
Being pregnant does not make you immune to trichomoniasis; in fact, some evidence suggests that the hormonal and immune changes of pregnancy may slightly increase susceptibility. If you were not tested before conception and have a sexual partner who has not been tested recently, it's possible to be carrying trich without knowing it from before the pregnancy began. It's equally possible to acquire it during pregnancy if your partner is infected and untreated.
Certain groups face higher baseline rates of trichomoniasis regardless of pregnancy status. According to CDC surveillance data, Black women face a prevalence rate of 9.6%, roughly twelve times the rate in non-Hispanic white women (0.8%), a disparity driven by structural factors including inequitable access to sexual health care, higher partner network prevalence, and reduced access to preventive resources. Other groups at elevated risk include people with multiple sexual partners, a history of prior STIs, or who are receiving care in high-prevalence settings such as correctional facilities. Trichomoniasis also becomes more common with age in women; unlike chlamydia and gonorrhea, women over 40 are at comparable or higher risk than women in their twenties.
One factor that catches many people off guard: a partner who carries T. vaginalis may have no symptoms whatsoever. Men in particular are frequently asymptomatic carriers. The infection can persist in the male urethra indefinitely without producing any obvious signs, which means a partner can sincerely believe they're uninfected while transmitting the parasite. This is why partner testing and treatment are not optional; they're a clinical requirement for breaking the reinfection cycle.
Another factor to consider is that trichomoniasis shares many symptoms with yeast infections. Read more about that topic in our Trichomoniasis or Yeast Infection? How to Tell and When to Test guide.
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When and How to Test for Trichomoniasis During Pregnancy
It is easy and safe to test for trichomoniasis during pregnancy, and if you do have the infection, it is one of the best things you can do for your pregnancy outcomes. A vaginal swab is part of the test. A healthcare provider can do it at a prenatal appointment, or you can do it at home with a rapid test kit. Collecting the sample is safe for the pregnancy and doesn't hurt it.
If you have symptoms like new discharge, a strange smell, itching, or burning, you should get tested at any point during your pregnancy, even if you're in the first trimester. The CDC says that pregnant women who have symptoms should be tested and treated no matter how far along they are. For women who don't have any symptoms, the decision to test is more complicated. The CDC doesn't recommend routine universal screening of asymptomatic pregnant women right now, but many doctors and researchers do because infections are often missed.
You can get tested for trichomoniasis three weeks after being exposed. Some STIs take a long time to show up, but T. vaginalis can be found fairly quickly after infection. If you know you were recently exposed to someone who tested positive, had unprotected sex, or got a new partner, wait at least three weeks before getting tested to make sure you get the most accurate result.
A Nucleic Acid Amplification Test (NAAT) is the best way to test for trichomoniasis because it finds the parasite's genetic material with high sensitivity and specificity. You can get quick tests for trichomoniasis at home, like the one from STD Test Kits. They use lateral flow technology on a vaginal swab sample and give you results in minutes. These tests are a good choice for pregnant women who want to check their status in private, away from a doctor's office, and without having to wait for a prenatal appointment.
One important thing to remember is that a negative result at 3 weeks is a good sign, but if you're still worried about a specific exposure, testing again at 6–8 weeks will give you even more peace of mind. If you test positive, get medical help right away. Your provider will tell you what to do next after you get treatment while you're pregnant.
For a full guide to using an at-home trich test during pregnancy, including what to do with the result, see: Is It Safe to Test for Trichomoniasis at Home During Pregnancy?
Treatment for Trichomoniasis During Pregnancy: What's Safe and What to Expect
This is the first question that most pregnant women want answered, and the answer is clearer than many people think: treating trichomoniasis while pregnant is safe. Metronidazole, the antibiotic used to treat it, has been studied a lot in pregnant women, and many clinical trials and meta-analyses have shown that it does not cause birth defects. It gets through the placenta, but the data consistently show that it is not very dangerous for the developing fetus. The Office on Women's Health says that metronidazole is safe to use at any point during pregnancy.
The CDC now says that pregnant women with trichomoniasis should take one 2-gram dose of metronidazole by mouth. Some providers, especially those who treat women with HIV, who have a higher risk of getting the infection again, may choose a seven-day course of 500mg twice a day. Research has shown that this is more effective at getting rid of the infection. It will depend on your situation what your provider decides. Tinidazole is another antibiotic that is sometimes used to treat trich, but it is not safe to use during pregnancy. Because of this, metronidazole is the only treatment for pregnant women.
One important detail to know is that the evidence for treating pregnant women with trichomoniasis who don't show any symptoms is more complicated. An earlier study suggested that administering metronidazole to asymptomatic pregnant women could marginally elevate the risk of preterm birth; however, this study employed an unconventional dosing regimen and has been challenged by more recent research. The current clinical guidelines stipulate that symptomatic pregnant women must invariably receive treatment, while the decision for asymptomatic women should entail a consultation with a healthcare provider regarding the specific risks and benefits pertinent to their situation.
You can't change how you treat your partner. If your partner isn't treated at the same time as you, you will almost certainly get sick again. About one in five people get trichomoniasis again within three months of finishing treatment. Most of these people get it again because their partner didn't get treated. Both partners must finish their treatment, and neither should have sex until the treatment is over and any symptoms have gone away.
It is also a good idea to test again after treatment. The CDC says that you should get tested again about three months after finishing treatment to make sure the infection is gone and you don't get it again. Because of the high rate of reinfection and the risks of pregnancy, this follow-up step is very important.
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Can a Baby Get Trichomoniasis During Birth?
Yes, but the risk is low, and it's one of the reasons treating trichomoniasis before delivery matters. Neonatal trichomoniasis occurs when the baby passes through the birth canal of an infected mother and is exposed to T. vaginalis in vaginal secretions. The parasite can then colonize the baby's respiratory tract or genitalia. In female newborns, maternal estrogens create a temporarily more hospitable vaginal environment for the parasite, which is why female infants are slightly more susceptible to colonization than male newborns.
When neonatal trichomoniasis does occur, the most common presentation is respiratory distress, as the baby inhales infected secretions during delivery, leading to tracheal or pulmonary colonization. Fever, irritability, cloudy-white vaginal discharge in female newborns, and urinary tract infection symptoms have also been reported. In rare cases, disseminated infection affecting multiple organ systems has been documented. These severe cases are genuinely uncommon, but they are the clearest argument for why maternal trich should be identified and treated before delivery rather than left to chance.
Treatment of the infection before delivery is the most effective prevention strategy. Successful antibiotic treatment clears the parasite from the genital tract, eliminating the transmission route during birth. If a mother is treated and clears the infection, the neonatal transmission risk is effectively eliminated. This is another reason why testing and treating trichomoniasis during pregnancy, not just at delivery, is clinically meaningful.
For the full clinical picture of what happens when a baby is exposed to trichomoniasis during birth, see: Can a Baby Get Trichomoniasis During Birth?
The Screening Gap: Why Trichomoniasis During Pregnancy Is Routinely Missed
Here's something that doesn't get enough airtime: most pregnant women in the United States are never screened for trichomoniasis. The CDC does not currently recommend routine screening for asymptomatic pregnant women, only symptomatic women or women who are HIV-positive, are covered by existing guidelines. Given that 70% to 85% of women with trichomoniasis have no symptoms, the practical implication is that the vast majority of cases during pregnancy go undetected unless the woman or her provider specifically asks for a test.
This is not a settled issue in the clinical world. Researchers published in the American Journal of Obstetrics and Gynecology in 2025 made the case that trichomoniasis should be made a reportable disease and that routine pregnancy screening guidelines should be reconsidered, specifically because of its association with preterm birth and low birth weight. The screening gap is particularly acute given that trich disproportionately affects populations already at elevated risk for poor pregnancy outcomes, including Black women, who face prevalence rates nearly twelve times higher than those in the general white female population.
What this means practically for pregnant women is simple: don't wait for your provider to bring it up. If you're sexually active, haven't been tested for trich in the past year, or have any reason to think you may have been exposed, ask for a test at your next prenatal appointment, or use an at-home rapid test between visits. The standard prenatal STI panel in the US includes testing for HIV, syphilis, hepatitis B, chlamydia, and gonorrhea. Trichomoniasis is not automatically included. You have to ask for it, or test for it yourself.
Lying awake at 2 a.m., running through symptoms that might be nothing or might be trich is exactly the kind of situation that at-home testing was designed to solve. A test takes minutes and gives you a clear answer, which is almost always better than weeks of uncertainty while you wait for the next prenatal appointment.
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What to Do If You Test Positive for Trichomoniasis During Pregnancy
A positive result during pregnancy is not a crisis; it's information, and information is what makes it possible to act. The steps are clear, and the timeline is manageable if you move quickly.
Contact your OB or midwife promptly to discuss treatment. They will confirm the diagnosis and prescribe metronidazole. Take the full course as directed. Tell your partner that they need to be tested and treated at the same time, using the same medication. Both of you should avoid sexual contact until treatment is complete and any symptoms have resolved. Arrange a follow-up test approximately three months after completing treatment to confirm clearance and rule out reinfection.
If your partner is reluctant to test or treat, that's a conversation worth having directly and early. Reinfection during pregnancy is a preventable outcome, and the only thing preventing it is both partners completing treatment. Many states allow expedited partner therapy (EPT), which lets a provider prescribe medication for a sexual partner without them needing their own clinic visit. Ask your provider whether EPT is available for trichomoniasis in your state.
Don't panic about what a positive result means for your baby. Most pregnancies with trichomoniasis, especially those where treatment happens before the third trimester, proceed normally. The risks associated with untreated trich are statistical associations across populations, not guarantees for any individual pregnancy. Early treatment dramatically reduces those risks. Your prenatal care team will monitor your pregnancy accordingly, and if you have concerns about preterm birth risk or other complications, those conversations are exactly what your appointments are for.
FAQs
1. Is it possible for trichomoniasis to lead to a miscarriage?
There is not a strong link between trichomoniasis and miscarriage in the first trimester. The more convincing evidence points to preterm birth, premature rupture of membranes, and low birth weight. These are all outcomes that are linked to the infection mainly in the second and third trimesters. If you're pregnant and worried about getting trich, the most important thing to do is get tested, not worry about the worst that could happen.
2. Is it safe to take metronidazole during the first trimester?
The data regarding metronidazole in early pregnancy is comforting. A lot of clinical trials and a big meta-analysis have shown that it doesn't cause birth defects, which means it doesn't seem to be teratogenic. Both the CDC and the Office on Women's Health say that symptomatic women can use it at any point during their pregnancy. Your doctor will look at each case separately, but the general fear that metronidazole is dangerous in the first trimester is not supported by the current evidence.
3. Can my partner still have trichomoniasis if they don't have any symptoms?
Of course. Men are the hidden causes of trichomoniasis transmission because they don't show symptoms very often. The parasite can stay in the male urethra for weeks or even months without causing any pain. A partner who really feels fine can still be infected and spread the disease. This is why you have to treat your partner at the same time as you treat yourself. It's the only way to stop the infection from coming back.
4. How soon after being exposed can trichomoniasis be found in a pregnant woman?
Three weeks after exposure is the best time to test for trichomoniasis. If you test too soon, you might get a false negative because the parasite might not be present in large enough amounts to be found. If you test negative before three weeks, test again after that. The standard at-home rapid test or clinical NAAT will be accurate starting three weeks after exposure.
5. Does trichomoniasis have a direct effect on the baby in the womb?
The parasite usually does not cross the placental barrier to infect the fetus while it is still in the womb. The primary risk to the fetus during pregnancy arises from the inflammatory effects of the infection on the cervicovaginal tissue, which activate cytokines that may compromise membranes and induce premature labor, rather than from direct fetal infection. When it does happen, the baby gets it through the birth canal during birth.
6. If I'm pregnant, can I use a trichomoniasis test at home?
Yes. A vaginal swab is part of an at-home trich test, which is safe to do while pregnant. The process of collecting the sample is not invasive and does not put the pregnancy at risk. If the result is positive, call your doctor right away to confirm it and start treatment. An at-home test is a good way to check your status between prenatal visits, especially if you have symptoms or have been around someone who has them.
7. What happens if I get trichomoniasis again while I'm pregnant?
If a partner doesn't get treated, it's possible and common for a woman to get reinfected while she's pregnant. The same treatment plan still stands: metronidazole, treating the partner at the same time, and retesting three months after the treatment is over. If you get a second infection while you're pregnant, let your doctor know. They may want to keep a closer eye on you for signs of preterm labor or other problems because the infection will last longer.
8. Is trichomoniasis checked for as part of regular prenatal tests?
No, not in the US. HIV, syphilis, hepatitis B, chlamydia, and gonorrhea are all common STIs that are tested for during pregnancy. Trichomoniasis is not always included. You must ask your provider for a trich test during pregnancy or use an at-home test if you want one. This is one of the most important things that is missing from regular prenatal care, and you should fight for it.
9. Does having trichomoniasis while pregnant make me more likely to get HIV?
Yes. T. vaginalis causes inflammation in the genital tract that breaks down the mucosal barrier, making it much more likely that someone will get or pass on HIV. The CDC says that people with trichomoniasis have a 2.1-fold higher risk of getting certain other infections. If you have HIV, the treatment for trichomoniasis is a little different. Your doctor will usually suggest a seven-day course of metronidazole instead of just one dose. This is because studies have shown that this longer regimen works better for this group of people.
10. Is it safe for mothers who are breastfeeding to take metronidazole?
There are small amounts of metronidazole in breast milk. The Office on Women's Health says that you should wait 12 to 24 hours after taking metronidazole before breastfeeding so that the milk's peak concentration can drop. For non-pregnant women with trich, tinidazole is an alternative that is not safe for breastfeeding mothers. If you're breastfeeding and need treatment, talk to your doctor about how to time your doses so that your baby doesn't get too much of the medicine.
Test Now, Answers Matter More When You're Pregnant
If there's one takeaway from everything above, it's this: trichomoniasis during pregnancy is common, frequently silent, and entirely treatable, but only if you know it's there. Waiting for symptoms that may never appear, or assuming that your routine prenatal panel covered it, are both ways of leaving something important to chance. During pregnancy, certainty beats guessing every time.
The Trichomoniasis At-Home STD Test Kit from STD Test Kits delivers results in minutes from a simple vaginal swab collected in complete privacy. If you want broader coverage, including the infections that frequently travel alongside trich, the 7-in-1 Complete At-Home STD Test Kit tests for trichomoniasis, chlamydia, gonorrhea, syphilis, herpes HSV-2, hepatitis B, and hepatitis C in a single collection. For your partner, the same kits apply; simultaneous testing and treatment is the only approach that actually works.
Visit STD Test Kits to see all available options. A test that takes minutes can answer the question that's been sitting in the back of your mind, and during pregnancy, that kind of clarity is worth having.
How We Sourced This: Our article was constructed based on current advice from the most prominent public health and medical organizations, and then molded into simple language based on the situations that people actually experience, such as treatment, reinfection by a partner, no-symptom exposure, and the uncomfortable question of whether it "came back." In the background, our pool of research included more diverse public health advice, clinical advice, and medical references, but the following are the most pertinent and useful for readers who want to verify our claims for themselves.
Sources
1. CDC STI Treatment Guidelines: Trichomoniasis
2. Trichomoniasis and Adverse Birth Outcomes: A Systematic Review and Meta-Analysis, PMC
4. Trichomoniasis, StatPearls, NCBI Bookshelf
6. Trichomoniasis, Office on Women's Health, U.S. Department of Health and Human Services
About the Author
Dr. F. David, MD is a board-certified infectious disease specialist focused on STI prevention, diagnosis, and treatment. He writes with a direct, sex-positive, stigma-free approach designed to help readers get clear answers without the panic spiral.
Reviewed by: Rapid STD Test Kits Medical Review Team | Last medically reviewed: April 2026
This article is for informational purposes and does not replace medical advice.