Maternal and fetal infection.

Although their incidence varies among populations, maternal-fetal infections are increasingly recognized to be among the most common causes of maternal and perinatal morbidity. The use of new techniques, including nucleic acid hybridization and direct fetal or trophoblastic cell sampling, continues to accelerate our knowledge of the epidemiology, microbiology, and immunology, as well as means to diagnose, treat, and prevent individual congenitally transmitted infections. Given the number and complexity of these infections, only selected aspects of recent advances are presented.