If you have a sexually transmitted disease (STD), or if you have symptoms that you are worried about, it is always a good idea to talk to a healthcare provider. Having an untreated STD during pregnancy can mean an increased risk of miscarriage or preterm delivery, although the exact risk varies by the type of STD.
It used to be that HIV meant pregnancy wasn't a good idea. But with today's available drugs, women with HIV have an excellent chance of having a healthy pregnancy with low odds of passing the virus to the baby -- if they seek treatment. Many experts recommend that all women be tested for HIV in early pregnancy regardless of whether they have risk factors.
Untreated syphilis definitely appears to increase risk of miscarriage, and it can cause life-threatening complications for the baby if the baby is born with congenital syphilis. Treatment is as simple as a course of antibiotics.
The risk of viral hepatitis during pregnancy varies by the type of hepatitis. Most viral strains do not increase risk of miscarriage, but viral hepatitis in the mother can pose risks for the newborn baby -- especially Hepatitis B.
Genital herpes is not proven to increase the risk of miscarriage. But it can cause problems for the baby if the mother contracts the virus during pregnancy or if active lesions are present at birth.
Some evidence suggests that untreated bacterial vaginosis is a risk factor for second-trimester miscarriage or preterm labor, although researchers aren't sure yet whether it actually causes miscarriages. Bacterial vaginosis is not strictly a STD.
Untreated gonorrhea might mean increased risk of preterm birth, plus complications for the baby immediately after birth. Gonorrhea can also lead to pelvic inflammatory disease.