A Crash Course in Having Sex During Your Third Trimester

Pregnancy changes your body and your lifestyle, but it doesn't have to change your sex life. In fact, having sex while expecting comes with a host of benefits, ranging from lowered blood pressure to improved sleep. Getting intimate can also improve your relationship with your partner before Baby arrives, says Jimmy Belotte, an Ob-Gyn in the Department of Obstetrics & Gynecology and Women's Health at Montefiore Health System, and an associate professor in the Department of Obstetrics & Gynecology and Women's Health and the Albert Einstein College of Medicine.

Despite the advantages of pregnancy sex, though, many couples are wary to hop in the sheets during the last few months of gestation. For starters, swollen limbs and an ever-growing belly may make your favorite positions uncomfortable. Many people are also anxious about harming the baby or introducing bacteria to the birth canal. But pregnancy sex shouldn't be feared! Here, two experts share their tips for having safe, enjoyable pregnancy sex during your third trimester.

Is Sex in the Third Trimester Safe?

"In general, sex is quite safe during pregnancy," says Mary Jane Minkin, M.D., a clinical professor in the Department of Obstetrics, Gynecology, and Reproductive Sciences at the Yale University School of Medicine. You won't hurt the baby since he's protected with amniotic fluid and blocked by your cervix. However, you shouldn't have sex with certain conditions like placenta previa (when the placenta partially or fully covers the cervix) or a high risk of premature labor. "Also, if you have ruptured membranes (your water breaks) do not have sex," or else you might introduce infection-causing bacteria to the birth canal, says Dr. Minkin.

If you're concerned about the safety of pregnancy sex during the third trimester, you should have an open discussion with your partner and healthcare provider. "It helps erase misconceptions, minimize barriers, and address potential and unresolved issues preventing the couple from enjoying their sexual experience during pregnancy," says Dr. Belotte.

What Does Sex Feel Like in the Third Trimester?

During pregnancy, your blood volume increases by about 40 percent. This enlargement of the blood vessels causes hyper-sensitivity in the breasts and the pelvic region, including your erogenous zones. Some women experience their best-ever orgasms while expecting. Others feel pain as dilated blood vessels in the cervix become irritated. The pain might be accompanied by bleeding, but it's nothing to be concerned about.

What’s the Best Position for Third Trimester Sex?

If a man's penis hits your enlarged cervix, you might experience pain and bleeding that turns you off from pregnancy sex. But changing positions can help alleviate discomfort, says Dr. Belotte. "Couples prefer certain sexual positions, like the woman on top or the couple laying down sideways with the pregnant woman in front," he says. Note that you should avoid having sex with the woman on her back, which could decrease blood flow to the fetus.

How Will Late Pregnancy Affect My Libido?

Every woman's sex drive is unique throughout pregnancy. But typically, "the rate of libido decreases the first trimester, increases in the second trimester, and decreases again in the third trimester for first-time pregnant mothers," says Dr. Belotte. Blame your bulging belly, uncomfortable aching body, and the fatigue associated with carrying a child for that third trimester decrease. If your sex life has come to a halt, just know this stage is temporary, and your desire to get frisky will probably return after Baby is born!

Will Sex Cause Early Labor?

Have you heard the old wive's tale that sex causes labor? It turns out there's no scientific evidence that intercourse triggers labor before the baby is ready, says Dr. Belotte. However, some people claim that orgasms get things moving if the baby is overdue – partly because sex releases oxytocin (a hormone associated with labor induction) and partly because orgasms mimic uterine contractions. Dr. Belotte adds that sperm contains a hormone-like substance called prostaglandins that's sometimes known to initiate labor when introduced into the birth canal.

What About Anal Sex and Oral Sex?

If you decide to have oral sex during the third trimester, it's important to take some precautions. Blowing air into the vagina could block your dilated blood vessels and cause an air embolism. Though it's a rare occurrence, an air embolism might harm your cardiovascular system and even cause death. What's more, having unprotected oral sex could give you the herpes simplex virus. Mothers with herpes can pass it to their infant during birth, possibly causing neurological damage, brain inflammation, and death.

Couples can also continue having anal sex during the third trimester. Keep in mind that anal sex can irritate hemorrhoids and anal fissures, and doing it unsafely may harm your baby. Moving the penis (or a sex toy) from the vagina to the anus without "washing it off" first introduces bacteria into the birth canal. The bacteria might cause infections—such as bacterial vaginosis and urinary tract infections—that could impact your pregnancy. Anal sex also comes with an increased risk of STI transmission. Many STIs have negative implications for a fetus, so it's vital to use a condom. Only have unprotected anal sex with partners who test negative for STIs.