STDs and Pregnancy

Finding out that you’ve contracted an STD—a sexually transmitted disease—is a horrifying, traumatic experience for anyone. If you’re pregnant, however, it’s not just your health that’s at stake, but that of your baby as well. Depending on the type of infection you have, an STD during pregnancy can cause any number of complications, including premature birth, miscarriage, birth defects, or even stillbirth. In this article we will discuss various STDs and how they can affect pregnancy.


Each year over 700,000 people contract this bacterial infection, which can cause vaginal discharge and pelvic pain in women, and painful urination for both women and men … or it may present with no symptoms at all.

If you are not pregnant, gonorrhea is an unpleasant but not life-altering experience, and it can be cured with antibiotics. For pregnant women, however, a history of having had gonorrhea increases the risk of ectopic pregnancy, a condition in which the fertilized egg attaches itself in the fallopian tubes or in some other location rather than in the uterus. This is because gonorrhea can lead to PID (pelvic inflammatory disease), an infection of the fallopian tubes that even with proper treatment can lead to some scarring inside the tubes).

Gonorrhea can also affect the baby, to whom it can be transferred through the birth canal during delivery. Potential risks for the baby range from eye infections (which can cause blindness) to stillbirth. Gonorrhea has also been linked to miscarriage, premature rupture of the membranes (PROM), and low birth weight. Fortunately, these grim outcomes are avoidable—gonorrhea is easily treatable with antibiotics.

Newly pregnant women are routinely tested for gonorrhea at the first opportunity. It can be asymptomatic, but possible symptoms include vaginal bleeding between periods, extra heavy bleeding during your period, or pain during sexual intercourse. If you do have gonorrhea, you should also be tested for chlamydia, which often accompanies it.


As with gonorrhea, the risks of chlamydia include an increased chance of ectopic pregnancy and pelvic inflammatory disease. The symptoms are also similar to those of gonorrhea—vaginal discharge, burning during urination, and bleeding after sex—and as with gonorrhea, the infection can be passed on to the baby via the birth canal during delivery, and it can cause severe eye and lung infections in the baby. This is also tested for routinely early in pregnancy and is also curable with antibiotics.


Trichomoniasis is a sexually transmitted infection caused by a single-celled parasitic organism known as trichomonas vaginalis. The symptoms in women include pain in the vagina and urethra leading to painful urination and pain during sexual intercourse. There may also be a foul-smelling, yellow-green vaginal discharge (the smell is often described as “fishy”). Consequences for the baby can include premature birth and low birth weight. Premature rupture of the membranes is also a possibility, and in rare cases a female infant can acquire the infection during birth, which will cause the newborn to exhibit vaginal discharge similar to the mother’s.


The consequences of syphilis during pregnancy can be quite severe. Worldwide, it is estimated that as many as 1.4 million pregnant women are infected with syphilis, and the disease causes an estimated 215,000 stillbirths annually. Early diagnosis and treatment for syphilis is important because this disease can be transmitted from mother to baby not just via the birth canal, but also through the placenta during pregnancy. As with gonorrhea and chlamydia, syphilis can be treated with antibiotics. If you are diagnosed with syphilis after your 20th week of pregnancy, it is recommended that an ultrasound be performed in order to determine whether fetal syphilis is present.

If syphilis is left untreated during pregnancy, the chance of stillbirth may be as high as 40 percent, and there is a 50 percent chance of passing the infection on to the baby. Fortunately, syphilis during pregnancy is rare in the US and Europe today, and by the late 1990s congenital syphilis averaged only 30 cases per 100,000 live births in the US. Treatment before the fourth month of pregnancy usually saves the baby from any damage. Symptoms of congenital syphilis may include a small head, jaundice, skin sores, seizures, and mental disability. Stillbirth is also not uncommon, and babies who survive may develop problems with their hearts, eyes, ears, brains, teeth, bones, or skin.

Testing for this is in early pregnancy is required by law.

Human Papilloma Virus (HPV)

HPV can occur in two forms. One is genital warts. The other is an infection of the cervix, often associated with an abnormal pap smear as well.

Genital warts can be diagnosed with a visual inspection, although your doctor may wish to conduct a biopsy if the appearance of the warts is unusual or if they do not respond to standard methods of treatment.

HPV of the cervix can sometimes be undetected. If present, it will show up on a pap smear test if an HPV test is done, but HPV testing on pap smears is not always routine. Many labs test paps for HPV based on a protocol called reflex testing. This means a normal pap might not get an HPV test unless the doctor specifically orders one, but an abnormal pap smear will automatically get tested for HPV.

It is possible for HPV to be transferred to the baby via the birth canal during delivery, causing warts to appear in the baby’s throat, but this is quite rare. Thus, HPV is NOT considered a basis for C-section birth. Treatment for genital warts will usually be postponed until after delivery, unless the condition is especially severe.

Hepatitis B

Hepatitis B in pregnancy can transfer to the baby during delivery. Most cases occur in women who are not actually sick, but they carry the virus in their bloodstream (they are “silent carriers,” and this type of infection is called chronic Hep B). The test for this is called Hep B surface antigen, and it is a routine test for ALL pregnant women. There are more than one million women in the US with chronic Hep B.

Babies born to these mothers must receive treatment within 12 hours after birth —or they stand a 90% chance of becoming lifetime carriers of the disease. The degree of danger depends largely on the time of infection; if the mother is infected early in her pregnancy, the risk that the baby will be infected is less than 10%, but it can rise as high as 90% if the infection occurs late in the pregnancy.

Due to the prevalence of this condition, all newborns are supposed to receive a Hep B vaccination after birth (and two more doses during infancy). Additionally, if the mother is surface antigen positive, the newborn also receives a dose of Hep B gamma globulin (called HBiG) within 12 hours. This almost always prevents the newborn from developing Hepatitis B.

According to expert opinion, women who carry Hep B are still advised to breastfeed, as the benefits of breastfeeding outweigh the remote risk of transmitting the virus to the newborn via breastmilk.

Genital Herpes

As with hepatitis, the risk of infecting the baby is higher (30–60%) if the infection in the mother occurs late in the pregnancy, near the time of delivery. For newborns, herpes infection is a potentially life-threatening condition that can cause blindness or brain damage in survivors. Although it is possible in rare cases for herpes to cross the placenta during pregnancy, more than 90 percent of all infections in newborns occur during passage through the birth canal, and almost all cases are due to the FIRST episode of genital herpes just prior to giving birth.

If you have a known diagnosis of herpes, then by definition you cannot have your first episode at the time of delivery. There is still a risk of transmission during vaginal birth if there is a recurrence of the virus, so for this reason, if you have active genital herpes sores at the time you go into labor, your doctor will almost certainly want to deliver the baby by cesarean section.

Furthermore, it is now a common practice to start anti-herpes medication (Zovirax or Valtrex) about one month prior to the due date to try to prevent a herpes breakout at the time of delivery.


HIV, the virus associated with AIDS, can easily be passed from mother to baby in a number of ways. It can cross the placenta during pregnancy or it can be transferred through the birth canal during delivery, and it is even possible for a baby to become infected while breastfeeding. A mother’s HIV infection is not necessarily a death sentence for her newborn, however—antiviral medications administered during pregnancy can greatly reduce the chances that the infection will be passed to the baby, possibly bringing them down to as low as 2%.

The US Public Health Service recommends that al pregnant women be tested for HIV as early as possible, and that women considered to be at high risk (e.g., those who have multiple sex partners while they are pregnant, who engage in prostitution, use certain drugs, or who have a partner who is HIV-positive) be retested at the beginning of their third trimester.

Talking to Your Doctor and Getting Tested for STDs

Many doctors test pregnant patients for sexually transmitted diseases as a matter of routine, but some do not. If you are pregnant and believe it is possible that you may have an STD, be sure to let your doctor know so that you can be tested and you and your doctor can be prepared for what is to come. Many STDs do not present any symptoms at all, so ask your doctor about STD testing, and do not assume that you are not infected just because you “feel fine.” If you have an STD that is not curable, or that cannot be treated in time for delivery of your baby, your doctor may also consider a C-section delivery.

The American Academy of Family Physicians recommends that all women be screened as early as possible in their pregnancies for hepatitis, gonorrhea, and HPV, among others, and further recommends that women who are under the age of 25 or who are at risk for chlamydia or gonorrhea (if, for example, they have multiple sex partners) should be rescreened at some point during their third trimesters.

Here are some questions to ask your doctor about pregnancy and STDs:

  • What STDs do you recommend I should be tested for?
  • If I test positive for a sexually transmitted infection, what are the chances that I will pass this infection on to my baby?
  • What changes in my lifestyle do you recommend in order to keep my baby safe?
  • Why should we wait until after the baby is born to treat my genital warts?
  • Can an ultrasound tell us whether my baby has contracted syphilis from me?

This page was last updated on 06/2017

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