Sexually transmitted diseases (STDs) have reached epidemic proportions in the United States and have captured the attention of both laypersons and health professionals. Of special concern is that most STDs can be transmitted vertically to the offspring of infected mothers. Since the advent of acquired immunodeficiency syndrome, other STDs have been at risk of being relatively disregarded. This paper, the first of two parts, reviews issues of prevalence, morbidity, mortality, prevention and treatment of syphilis and gonorrhea as they affect the maternal-fetal dyad.