Will an STD Affect My Pregnancy or Breastfeeding?

Chlamydia | Gonorrhea | Syphilis | Herpes | Hep B | Hep C | HIV | HPV

Most STDs or STIs can affect pregnancies or newborns in some way; from increasing the likelihood of having a premature delivery and/or influencing birth weight, to causing serious infections in the newborn that can become fatal.

Different STDs and Pregnancy


In women, untreated chlamydia can lead to pelvic inflammatory disease (PID) and cause permanent damage leading to infertility or potentially fatal ectopic pregnancy. Chlamydia can increase the risk of miscarriage and premature birth. It can also cause eye infections or even pneumonia in newborns. Chlamydia is a bacterial infection that can be treated with antibiotics during pregnancy. The medication newborns are given at birth to prevent gonorrhea infections of the eye also prevents chlamydia eye infections.

Mothers cannot pass chlamydia to their babies through breastfeeding.


In women, untreated gonorrhea can lead to scarring of the Fallopian tubes causing permanent damage leading to infertility or potentially fatal ectopic pregnancy or miscarriage. Pregnant women with gonorrhea can pass the infection to their babies during childbirth. Gonorrhea can cause premature birth. Babies born while the mother is infected can get eye infections that may lead to blindness. They may also develop joint infections and potentially deadly blood infections. All newborns are given medication at birth to prevent eye infection. Gonorrhea can be cured with antibiotics, so pregnant women can be treated for gonorrhea during pregnancy. However an uptick in “super gonorrhea” has doctors concerned. A new strain of antibiotic resistant gonorrhea has doctors concerned and makes it even more important that you test often and test early especially when considering a pregnancy.

Mothers cannot pass gonorrhea to their babies through breastfeeding.


Syphilis is a bacterial infection that is very harmful to infants and unborn babies. It can cause a mother to miscarry or the baby to be stillborn. Syphilis can easily be transmitted to a fetus from the placenta or transfer to the baby in the birth canal during delivery. It can cause serious or even fatal infections. Infants with congenital syphilis are often born prematurely and if left untreated, syphilitic babies will likely develop serious issues with internal organs like the heart, brain, skin, eyes, ears, bones and teeth. Syphilis can be treated during pregnancy with antibiotics to both decrease the risk of spreading it to the baby and stop the infection’s progression in the mother. Even if symptoms are not obvious early on, infants with congenital syphilis can develop serious health problems years later like blindness, hearing loss, deformities of the teeth and bones, and other dangerous neurological issues.

Primary syphilis chancres (sores) most frequently appear on the genitals, but can also occur on the fingers, mouth, lips, tongue, tonsils, anus and breasts and nipples. If a chancre is present on the breast or nipple, mothers should not breastfeed.

Herpes 1 and Herpes 2 (HSV-1 & HSV-2)

Typically, oral herpes does not affect pregnancies. Although published reports on oral herpes disease in pregnancy remain scarce and no clear management guidelines exist, rare cases of gingivostomatitis (an infection of the mouth and gums that leads to swelling and sores) have been reported during the first trimester and are thought to be linked to oral herpes.

Genital herpes, on the other hand, can be very dangerous to an infant during childbirth. If the mother has an active infection (whether or not symptoms are present), the baby can contract the virus. If the baby contracts the virus during birth, it can affect the skin, eyes, mouth, central nervous system, and/or even spread to internal organs via disseminated disease which can cause organ failure and lead to death. Disseminated diseases that occur as a result can include hepatitis, pneumonitis, disseminated intravascular coagulation, or a combination, with or without encephalitis or skin disease. To prevent transmission to the infant, doctors will perform a C-section (cesarean section) delivery. Treatment of lesions during pregnancy involves antiviral medication.

According to the American College of Obstetricians and Gynecologists, “women who have their first genital herpes infection in late pregnancy (whether symptomatic or asymptomatic) and who give birth vaginally have a high risk (30–50%) of transmitting the virus to their infants. Similarly, nonprimary first-episode HSV infection occurring late in pregnancy also has a high risk of vertical transmission. The risk of transmission during a vaginal delivery is much lower with recurrent infection (less than 2–5%). Currently, most newborns infected with HSV are delivered to women who have asymptomatic or unrecognized infections. Genital herpes infection is classified as primary when it occurs in a woman with no evidence of prior HSV infection (ie, seronegative for both HSV-1 and HSV-2), as a nonprimary first episode when it occurs in a woman with a history of heterologous infection (eg, first HSV-2 infection in a woman with prior HSV-1 infection or vice versa), and as recurrent when it occurs in a woman with clinical or serologic evidence of prior genital herpes (of the same serotype).”

After delivery, breastfeeding is considered safe unless there is a herpes lesion or sore on the breast.

Hepatitis B (HBV)

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A baby can contract hepatitis B during childbirth if the mother carries the virus. Infected newborns can develop liver disease from hepatitis B, which is sometimes fatal. Doctors will vaccinate newborns born to hepatitis B-positive mothers with antibodies to protect them from infection. While there is no cure for hepatitis B, there is a vaccine to prevent it.

Hepatitis B is not spread through breastfeeding. 

Hepatitis C (HCV)

Hepatitis C can be transmitted from an infected mother to her baby during delivery. The rate of hepatitis C transmission from mother to child is 1 in 20. Currently, there is no vaccine or another way to help prevent the baby from contracting hepatitis C at birth. If a child gets hepatitis C at birth, their health (especially liver health) will need to be monitored. One in four children will clear the virus on their own; the remaining will become carriers of the virus.

Whether or not hepatitis C can be transmitted via breast milk is not 100 percent certain. Doctors recommend women with hepatitis C breastfeed.


With treatment throughout the pregnancy, the likelihood of transmitting HIV to a newborn during childbirth drops to 2 percent; when left untreated the virus has a 25 percent chance of being spread to the baby. For both the mother or the newborn, HIV can develop into AIDS, which is deadly. HIV can cross the placenta and infect a fetus, or infect a newborn during delivery. Antiviral therapy (ART) is given to mothers to help treat HIV as well as prevent its transmission to the baby. Sometimes a cesarean section (C-section) delivery is scheduled.

Mothers with HIV should not breastfeed, as HIV can be given to the baby via breast milk.

HPV (Human Papillomavirus)

When developed during pregnancy, HPV treatment of the mother is often delayed until after delivery of the baby. HPV can cause genital warts to grow and sometimes genital warts can grow even larger due to pregnancy hormones. If they grow big enough to obstruct the birth canal, the baby may have to be delivered via cesarean section (C-section). In very rare cases, a mother can pass HPV to her baby during childbirth. An extremely small number of these infants develop a condition that causes tumors to grow in the throat called recurrent respiratory papillomatosis (RRP). These tumors are surgically removed, but often come back.

Mothers with HPV can breastfeed their babies.


In women, untreated trichomoniasis can lead to scarring of the Fallopian tubes causing permanent damage leading to infertility or potentially fatal ectopic pregnancy or miscarriage. Trichomoniasis can also cause low birth weight and premature babies. Pregnant women with trichomoniasis can pass the infection to their babies during childbirth.

Mothers cannot pass trichomoniasis to their babies through breastfeeding. During treatment for trichomoniasis, the CDC recommends that breastfeeding women, stop breastfeeding during the course of metronidazole treatment and for 12-24 hours after the last day of the prescription. For treatment with tinidazole, the CDC recommends stopping breastfeeding for the course of treatment and until three days after the last dose has passed.

If you are being treated for an STD, ask your doctor about the possible effects the medication can have on your breastfeeding baby.

Medically Reviewed by on October 3, 2023

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Author: Nick Corlis

Nick Corlis is a writer, marketer, and designer. He graduated from Texas State University in San Marcos, Texas, with a degree in Digital Communications. Nick is proud to be able to help eliminate the stigma of STD testing through his writing and is always trying to advocate the importance of your sexual health. Before STDcheck, his favorite way to develop his writing skills was by accepting various writing jobs in college and maintaining multiple blogs. Nick wears many hats here at STDcheck, but specifically enjoys writing accurate, well-researched content that is not only informative and relatable but sometimes also contains memes. When not writing, Nick likes to race cars and go-karts, eat Japanese food, and play games on his computer.