Sexually transmitted infections are usually discussed as an adult health issue, so the question surprises people: can you be born with an STD? The answer is yes. Several infections can pass from mother to child during pregnancy, during delivery, or afterward through breastfeeding. Clinicians call these congenital or perinatal infections, and they range from treatable nuisances to genuinely dangerous conditions. The encouraging flip side: nearly all of this risk can be found and managed with routine testing and treatment during pregnancy. Here is what expecting parents, and anyone planning a pregnancy, should know.
Which infections can pass to a baby
Different infections reach the baby by different routes:
- Syphilis crosses the placenta during pregnancy. Untreated, it can cause miscarriage, stillbirth, prematurity, or congenital syphilis, which can damage a newborn's bones, brain, and organs. This is the infection driving the most public health concern in the United States right now.
- HIV can pass during pregnancy, delivery, or breastfeeding.
- Hepatitis B commonly passes at birth, which is why newborns receive the hepatitis B vaccine, and additional protective antibodies when the mother is known to carry the virus, within hours of delivery.
- Genital herpes (HSV) is most dangerous when a mother acquires it late in pregnancy or has active sores at delivery. Neonatal herpes is rare but serious, affecting the skin, brain, or multiple organs.
- Gonorrhea and chlamydia pass through the birth canal during delivery and classically cause newborn eye infections, and chlamydia can also cause pneumonia in the first months of life.
- Trichomoniasis and hepatitis C pass to the baby less commonly, and HPV transmission at birth is rare.
Why this is getting attention: congenital syphilis is rising
After decades of decline, congenital syphilis has surged nationally, rising more than tenfold over the past decade, and maternal syphilis continued climbing between 2022 and 2024. California has fortunately been bending its curve downward in recent years, but the burden remains substantial, which is why California now emphasizes syphilis testing not just at the first prenatal visit but again in the third trimester. Nearly every case of congenital syphilis is preventable when the mother is tested and treated in time. We covered the national and California numbers in more detail in our 2026 STD update.
How prenatal testing works
Standard prenatal care includes screening at the first prenatal visit for HIV, syphilis, and hepatitis B, and testing for chlamydia and gonorrhea for pregnant patients under 25 and anyone with risk factors. Patients with ongoing risk, and everyone in high prevalence areas, are retested later in pregnancy. If you are pregnant and have not had this testing, or you may have had an exposure since your last tests, ask for it. It is a routine, expected part of care, not an accusation.
Even better is knowing your status before pregnancy. A full panel STD test before trying to conceive lets any infection be treated on your own schedule rather than under the time pressure of a pregnancy.
How transmission is prevented
This is where modern medicine shines:
- Syphilis found in pregnancy is treated with penicillin, which treats the mother and protects the baby.
- HIV managed with antiretroviral therapy, combined with precautions at delivery and preventive medication for the newborn, reduces mother to child transmission to less than 1 percent.
- Chlamydia, gonorrhea, and trichomoniasis are cured with antibiotics that are safe in pregnancy. Newborns also routinely receive protective antibiotic eye ointment at birth.
- Herpes is managed with suppressive antiviral medication in the final weeks of pregnancy, and a cesarean delivery is recommended when active sores are present at labor.
- Hepatitis B transmission is largely prevented by the birth dose vaccine plus immune globulin for at risk newborns.
Signs of infection in a newborn
When transmission does occur, signs may appear at birth or in the first weeks: eye discharge or redness, a persistent cough or pneumonia like illness, skin blisters or an unusual rash, jaundice, poor feeding, fever, or irritability. Any of these in a newborn deserves prompt pediatric evaluation, and parents should mention any known or possible infection during pregnancy, because that history changes what doctors look for. Many congenital infections can be treated in the newborn, and earlier is always better.
If you are pregnant, or planning to be
The single most useful action is simple: get tested, and get your partner tested. At Advanced Urgent Care of Pasadena we provide pregnancy testing and confidential STD testing and treatment with an on-site laboratory, seven days a week, no appointment needed. We treat what urgent care should treat, refer HIV positive patients promptly to specialist care, and help you connect with an obstetrician for prenatal care. Walk in Monday through Friday 8 AM to 8 PM or weekends 9 AM to 5 PM. We take our last patient 30 minutes prior to close. Questions? Call (626) 304-0404.