Maternal and Fetal Infections In pregnancy, infections are a common complication—but women may not have obvious symptoms, or they may show different symptoms of an infection. Group B Streptococcus You’ve probably never heard of group B streptococcus. That’s because you didn’t need to before you were pregnant. This bacterium generally doesn’t cause problems for healthy nonpregnant women. But it can cause illness in pregnant women and their babies. Here’s what you need to know. Listeriosis You’ve probably been warned not to eat brie cheese or order your steak cooked to anything less than medium. Why do you have to take these precautions? Listeriosis. Learn more about this food-borne illness and how to avoid it. Toxoplasmosis Toxoplasmosis is not only harmful to moms-to-be, but also to their unborn babies. If you haven’t heard of toxoplasmosis, you’ll definitely want to brush up on this new word. Herpes It is important that women avoid contracting herpes during pregnancy, because a first episode during pregnancy creates a greater risk of transmission to the newborn. Acquired Immune Deficiency Syndrome (AIDS)/Human Immunodeficiency Virus (HIV) HIV can be passed to a child when he or she is in the mother's womb or as the infant passes through the birth canal. The virus has also been detected in breast milk. Urinary Tract and Kidney Infections During pregnancy, the kidney enlarges and the bladder is compressed by the growing uterus. These and other factors make it more likely for a woman to develop a urinary tract infection. Chorioamnionitis Chorioamnionitis is an infection of the membranes and amniotic fluid. It occurs in about 1 to 2 percent of all pregnancies, but is much more common in preterm births. Hepatitis B (HBV) in Children An infant or young child who contracts hepatitis B is at greater risk of staying infected with the virus and of having life-long liver problems, such as scarring of the liver and liver cancer.