Decline in Perinatal HIV Transmission in New York State (1997-2000)

Perinatal transmission of HIV has declined significantly in New York State (NYS) since the state implemented a 3-part regimen of zidovudine prophylaxis in the antenatal, intrapartum, and newborn periods. The current study describe the factors associated with perinatal transmission in the state from 1997-2000, the first 4 years of NYS's comprehensive program through which all HIV-exposed newborns were identified through universal HIV testing of infants.

The authors performed a population-based observational study including all HIV-exposed newborns whose infection status was known and their mothers identified in NYS through the universal Newborn HIV Screening Program (NSP) from February 1997 to December 2000. The researchers reviewed antepartum, intrapartum, newborn and pediatric medical records of HIV-positive mothers/infants for history of prenatal care, antiretroviral therapy (ART), and infant infection status; they also examined risks associated with perinatal HIV transmission.

The investigators found that the proportion of HIV-infected pregnant women who received 3 or more prenatal-care visits increased during the study period from 76.4 percent in 1997 to 85.4 percent in 2000. An increasing proportion of women received ART at during pregnancy, delivery, or during the newborn period, rising from 63.8 percent in 1997 to 96 percent in 2000. Intrapartum and newborn ART regimens increased from 48.5 percent in 1997 to 74.2 percent in 2000. Combination ART in the prenatal period increased from 16.2 percent in 1997 to 67.2 percent in 2000. Elective cesarean deliveries increased from 6.5 percent in 1997 to 35.2 percent in 2000. Perinatal HIV transmission decreased each year, from 11 percent in 1997 to 8.6 percent in 1998 to 7.1 percent in 1999 to 3.7 percent in 2000.

The authors performed bivariate analysis of HIV-positive women delivering and found that white women had a higher risk of transmission (10.4 percent) than black women (7 percent). Women over age 40 were 2.2 times more likely to transmit HIV than women 20-29 years old (13.9 percent and 6.3 percent, respectively). Residents of New York City had a higher risk of transmission than HIV-positive women living outside the city.

Women with no prenatal care, with infants of low birth weight, or who had vaginal delivery instead of elective cesarean delivery were more likely to transmit HIV.

A 3-part ART regimen administered in the prenatal, intrapartum, and newborn periods was associated with the lowest rate of transmission, compared with other drug regimens. Abbreviated ART regimens were also associated with reductions in transmission compared with no prenatal ART.

"Public health policies to improve access to care for pregnant women and advances in clinical care, including receipt of appropriate preventive therapies, have contributed to declines in perinatal transmission in NYS," the authors concluded.

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