RISK-FACTORS FOR MOTHER-TO-CHILD TRANSMISSION OF HUMAN IMMUNODEFICIENCY VIRUS-1 INFECTION

OBJECTIVE: Our aim was to examine maternal, obstetric, and infant char acteristics of mother-to-child transmission of human immunodeficiency virus-1 in Nairobi, Kenya. STUDY DESIGN: Proviral human immunodeficien cy virus-1 was detected by polymerase chain reaction in peripheral blo od samples taken between 6 weeks and 3 months of age from 107 children born to human immunodeficiency virus-1 seropositive women. The associ ation of maternal, infant, and obstetric variables with human immunode ficiency virus-1 transmission was examined. RESULTS: The mother-to-chi ld transmission rate was 31% (95% confidence interval 21.6 to 40.2) as defined by the presence of proviral human immunodeficiency virus-1 in the infant. Variables associated with transmission in a univariate an alysis included placental inflammation (7/12 in the transmitting group as compared with 2/22 in nontransmitters, p = 0.006), low maternal CD 4 and high CD8 percentages (21% and 52%, respectively, in transmitting mothers and 32% and 40% in nontransmitting mothers; p = 0.001), and t he gender of the neonate (20/29 infected neonates were female as compa red with 26/65 noninfected children, p = 0.02). Sexually transmitted d iseases were found more often in transmitting mothers but the differen ces were not significant. Birth weight and gestational age were not re lated to vertical transmission of human immunodeficiency virus-1. CONC LUSION: Risk factors for mother-to-child transmission of human immunod eficiency virus-1 included chorioamnionitis, an impaired maternal immu ne status, and female gender.