Objective: To investigate the hypothesis that labour and delivery events, perinatal characteristics, and maternal factors are only associated with intrapartum HIV transmission, and not with intrauterine HIV transmission.
Methods: In the New York City Perinatal HIV Transmission Collaborative Study 276 infants of HIV-infected women were followed prospectively and had results of early polymerase chain reaction (PCR) tests available. Among infected children, intrauterine infection was presumed if HIV DNA was detected by PCR in samples collected from children aged ≤ 3 days, and intrapartum infection was presumed if HIV DNA was not detected in these early samples. The proportion of infants with presumed intrauterine and intrapartum infections were compared by selected intrapartum, perinatal and maternal characteristics.
Results: Presumed intrapartum infection was found in 7% of infants delivered by Cesarean section and, among infants delivered vaginally, those with longer duration of membrane rupture (> 4 h) were significantly more likely to have presumed intrapartum HIV infection (22%) than those with shorter duration (9%; P = 0.02). There were no differences in presumed intrauterine HIV infection by mode of delivery or longer duration of membrane rupture. Infants born preterm and small for gestational age had significantly higher risks of presumed intrapartum infection, but only those who were small for gestational age had higher risks of intrauterine infection.
Conclusion: Our results support the notion that selected intrapartum conditions, long duration of membrane rupture prior to delivery in particular, are independent risk factors for maternal–infant transmission, and suggest that preterm infants may be especially vulnerable to intrapartum HIV exposure.
1Gertrude H. Sergievsky Center, Columbia University
2Harlem Hospital Center, New York
3Medical and Health Research Association of New York City, New York
4New York City Department of Health, New York
5Bronx-Lebanon Hospital, New York
6Metropolitan Hospital, New York
7Montefiore Hospital, New York
8Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
10Requests for reprints to: Dr Louise Kuhn, Sergievsky Center, Columbia University, 630 W 168th Street, Unit 16, New York NY 10032, USA.
Sponsorship: Supported by Cooperative Agreement No. U64 CCU 200937 between the Centers for Disease Control and Prevention and Medical and Health Research Association of New York City, Inc.
Date of receipt: 25 July 1996; revised: 29 November 1996; accepted: 2 December 1996.