Hesperian Health Guides

Pregnancy and STIs

NWTND sti Page 20-1.png

When a pregnant woman has a STI, her baby can be exposed to the infection through the mother’s blood during pregnancy, during birth when they pass through the vagina, or in breastmilk.

An untreated or uncontrolled STI can harm both the woman and her baby. Babies can be born too early or too small, and they can be born sick or get sick later on. Tests for STI either let you know that you have nothing to worry about or will help you get the right treatment during pregnancy or at birth. Treatment can cure mother and child, and treat the woman’s partner too.

Gonorrhea and chlamydia

Gonorrhea or chlamydia can pass to the baby during birth and can cause eye infections, blindness, or serious lung problems. To prevent eye infections and blindness, put erythromycin ointment in the baby’s eyes right after birth (see Newborns Babies and Breastfeeding).


Syphilis can pass to the baby in the womb, causing it to be born too early, deformed, or dead. Get tested and treatment during pregnancy.


Herpes can pass to a baby during birth if the mother has sores on the genitals. If you are newly diagnosed with herpes or have sores, it is best to give birth in a hospital. They might deliver the baby through an operation (C-section) and treat the baby after birth.

a woman entering a health clinic


Warts will not usually pass to a baby, but they can bother you during pregnancy. Treat warts or wait until after birth to treat them. Because warts may bleed during birth, consult a health worker about your options for giving birth in a hospital.

Hepatitis B

A pregnant woman can pass her hepatitis B to her baby. The baby will need the HepB vaccine right after birth and other treatment to prevent hepatitis B infection.


Testing for HIV when pregnant means you can get medicines to prevent passing it to the baby. HIV medicines will protect the mother and the baby.

This page was updated:16 Oct 2019