Obstetric factors and mother-to-child transmission of human immunodeficiency virus type 1: the French perinatal cohorts. SEROGEST French Pediatric HIV Infection Study Group.

Objective: We attempted to determine whether the risk of mother-to-child transmission of human immunodeficiency virus type 1 is related to events in pregnancy, labor, and delivery.

Study Design: In a prospective multicenter cohort study of human immunodeficiency virus type 1-infected mothers and their children, we studied pregnancy histories, labor (including gestational age, induction, membrane rupture, length of labor, intrapartum procedures, bleeding, infection, antiseptic technique, and antiretroviral therapy), and conditions of delivery.

Results: Among 1632 singleton infants, 310 were confirmed infected with human immunodeficiency virus type 1 at age 18 months (19.