A yeast infection during pregnancy is not dangerous to your baby. A large systematic review covering nearly 50,000 pregnancies found no strong evidence that vaginal yeast infections, whether symptomatic or not, increase the risk of preterm birth, miscarriage, stillbirth, low birth weight, or any other adverse outcome for the newborn. It’s uncomfortable and annoying, but it’s also one of the most common infections in pregnancy, and it’s safely treatable.
Why Yeast Infections Are So Common in Pregnancy
Outside of pregnancy, about 20% of women carry yeast in the vagina without symptoms. During pregnancy, that number climbs to roughly 30%, with some estimates ranging as high as 50%. The spike happens because pregnancy changes the vaginal environment in ways that favor yeast growth.
Rising estrogen levels are the main driver. Estrogen increases the production of glycogen, a sugar stored in vaginal tissue, which feeds yeast and helps it multiply. At the same time, estrogen helps yeast dodge the immune system by interfering with how immune cells recognize and destroy the fungus. On top of that, pregnancy naturally suppresses certain immune responses to protect the developing baby, which gives yeast another advantage. These shifts are most pronounced in the second and third trimesters, which is when infections tend to peak.
Risks to Your Baby Are Minimal
The most thorough analysis available, a meta-analysis published in BMC Women’s Health that pooled data from 57 studies, found essentially no increased risk of preterm birth in women with vaginal yeast infections. The odds ratio was 1.01, meaning the risk was statistically identical to women without yeast infections. The researchers also found no link between yeast infections and spontaneous abortion, premature rupture of membranes, stillbirth, low birth weight, small-for-gestational-age babies, placental inflammation, or neonatal death.
The one small concern is passing yeast to the baby during delivery. If you have an active infection when you give birth vaginally, the baby can develop oral thrush or a yeast-related diaper rash in the first weeks of life. Thrush shows up as white, velvety patches on the tongue and inside the mouth that may bleed slightly when wiped. Babies with thrush sometimes refuse to nurse because of soreness. Both thrush and yeast diaper rash are easily treatable and not serious, but treating your infection before delivery reduces the chance of passing it along.
Safe Treatment Options
Topical antifungal creams and vaginal suppositories are the standard treatment during pregnancy. The CDC recommends only topical treatments applied for seven days. The two most commonly used active ingredients are clotrimazole (1% cream) and miconazole (2% cream or 100 mg suppository), both applied vaginally once daily for seven days. These do not cause birth defects or pregnancy complications and can be used at any point during pregnancy.
A seven-day course works better than a shorter one during pregnancy. The hormonal environment that encouraged the infection in the first place makes yeast harder to eliminate, so the longer treatment gives the medication more time to work. One-day or three-day formulas marketed for non-pregnant women are less reliable here.
Why Oral Antifungals Are Avoided
The oral pill commonly used for yeast infections outside of pregnancy (fluconazole, sold as Diflucan) is not recommended during pregnancy. Some studies have suggested a possible link between oral fluconazole and miscarriage, particularly when taken between weeks 7 and 22. While the FDA stated in 2019 that available evidence does not definitively prove a single 150 mg dose raises miscarriage risk, the picture is murky enough that the CDC advises against using it.
At higher doses (above 150 mg or prolonged use over many weeks), the concern is more concrete. A pattern of birth defects involving the head, face, bones, and heart has been documented in children born to women who took 400 to 1,200 mg daily for extended periods to treat severe fungal infections. A single low dose is unlikely to cause birth defects, but since safe topical alternatives exist, there’s no reason to take the chance.
Make Sure It’s Actually a Yeast Infection
This matters more during pregnancy than at any other time, because bacterial vaginosis (BV) can mimic a yeast infection and does carry pregnancy risks including preterm birth. The two look and feel different if you know what to check.
A yeast infection produces thick, white, cottage cheese-like discharge. It typically causes intense itching and irritation but little to no odor. BV, on the other hand, causes thin, grayish discharge that’s often heavier in volume and comes with a noticeable fishy smell, especially after intercourse. If your symptoms lean more toward odor and thin discharge than itching and thick discharge, it’s worth getting tested rather than self-treating with an antifungal that won’t help BV.
If you’ve had yeast infections before and recognize the symptoms clearly, using an over-the-counter seven-day cream is reasonable. But if this is your first infection, or if the symptoms are ambiguous, or if treatment doesn’t resolve it within a week, getting a proper diagnosis ensures you’re treating the right thing.
Reducing Your Chances of Recurrence
Because the hormonal conditions that promote yeast persist throughout pregnancy, reinfection is common. You can lower the odds by wearing cotton underwear, avoiding tight-fitting pants, changing out of wet swimsuits or workout clothes promptly, and skipping scented soaps or douches in the vaginal area. None of these measures are guaranteed to prevent an infection in the face of pregnancy hormones, but they reduce the extra triggers you can control.
If you keep getting infections despite treatment, your provider may recommend a longer course of topical therapy or periodic maintenance treatment. Recurrent yeast infections during pregnancy are frustrating but still manageable with the same safe topical options.