Efficacy and safety of 1-month postpartum zidovudine-didanosine to prevent HIV-resistance mutations after intrapartum single-dose nevirapine.

BACKGROUND: Intrapartum single-dose nevirapine plus third trimester maternal and infant zidovudine are essential components of programs to prevent mother-to-child transmission of human immunodeficiency virus (HIV) in resource-limited settings. The persistence of nevirapine in the plasma for 3 weeks postpartum risks selection of resistance mutations to nonnucleoside reverse-transcriptase inhibitors (NNRTIs). We hypothesized that a 1-month zidovudine-didanosine course initiated at the same time as single-dose nevirapine (sdNVP) would prevent the selection of nevirapine-resistance mutations. METHODS: HIV-infected pregnant women in the PHPT-4 cohort with CD4 cell counts >250 cells/mm3 received antepartum zidovudine from the third trimester until delivery, sdNVP during labor, and a 1-month zidovudine-didanosine course after delivery. These women were matched on the basis of baseline HIV load, CD4 cell count, and duration of antepartum zidovudine to women who received sdNVP in the PHPT-2 trial (control subjects). Consensus sequencing and the more sensitive oligonucleotide ligation assay were performed on samples obtained on postpartum days 7-10, 37-45, and 120 (if the HIV load was >500 copies/mL) to detect K103N/Y181C/G190A mutations. RESULTS: The 222 PHPT-4 subjects did not differ from matched control subjects in baseline characteristics except for age. The combined group median CD4 cell count was 421 cells/mm3 (interquartile range [IQR], 322-549 cells/mm3), the median HIV load was 3.45 log10 copies/mL (IQR, 2.79-4.00 log10 copies/mL), and the median duration of zidovudine prophylaxis was 10.4 weeks (IQR, 9.1-11.4 weeks). Using consensus sequencing, major NNRTI resistance mutations were detected after delivery in 0% of PHPT-4 subjects and 10.4% of PHPT-2 controls. The oligonucleotide ligation assay detected resistance in 1.8% of PHPT-4 subjects and 18.9% of controls. Major NNRTI resistance mutations were detected by either method in 1.8% of PHPT-4 subjects and 20.7% of controls (P < .001). CONCLUSIONS: A 1-month postpartum course of zidovudine plus didanosine prevented the selection of the vast majority of NNRTI resistance mutations.

Association of low CD4 cell count and intrauterine growth retardation in Thailand.

OBJECTIVE: Each year, intrauterine growth retardation (IUGR) affects 20-30 million neonates worldwide, mostly in resource-limited settings. Increased perinatal and infant mortality has been associated with IUGR. Some studies have suggested that HIV infection could increase the risk of IUGR. To confirm this hypothesis, we examined the association between HIV-related factors and the risk of IUGR in Thailand. PATIENTS AND METHODS: Data from a cohort of 1436 HIV-infected pregnant women enrolled in the "Perinatal HIV Prevention Trial-1", a clinical trial conducted from 1997 to 1999 in Thailand, were analyzed using a logistic regression, adjusting for risk factors usually associated with IUGR. RESULTS: The rate of IUGR was 7.6%. Adjusting for a short maternal height, low body mass index, small weight gain during pregnancy, and infant female sex, a low maternal CD4 percentage was independently associated with IUGR (odds ratio 0.96, per 1% increment, 95% confidence interval 0.93 to 0.99, P = 0.03). CONCLUSIONS: The current World Health Organization recommendation to initiate combination antiretroviral therapy for immunocompromised women as early as possible during pregnancy for their own health and for the prevention of HIV mother-to-child transmission is likely to also decrease the incidence of IUGR. Encouraging immunocompromised HIV-infected women who plan to become pregnant to wait until immune restoration has been achieved may help to reduce the risk of IUGR.