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Background:  Since 1998 U.K. guidelines have recommended short-course zidovudine monotherapy (ZDVm) for HIV⁺ women with CD4 > 200 cells/mL and HIV viral load < 10,000 RNA copies/mL who intend to deliver by pre-labor caesarian section, and a combination of 3 or more antiretroviral drugs for all other women. We describe 33 months mean follow-up of these women treated in pregnancy for their own health or to prevent mother-to-child HIV transmission (MTCT). One transmission to a mother on combined ART was documented.

Methods:  All women delivering at the 6 participating London Hospitals since January 1, 1998 are included in the analysis if they presented before labor, delivered after 24 weeks’ gestation, received ART befpre delivery and attended at least once after delivery. CD4⁺, viral load, therapy, and clinical data are collected prospectively. Interim data are presented on women delivering before December 31, 2002. Presentation and outcomes were compared by treatment—ZDVm vs combined ART—and analyzed by c² and t-test.

Results:  The 310 women were mostly of black of African origin (86%), para 1, with a median age of 31 years at delivery. The median gestation at first antenatal clinic attendance was 16 weeks (3.1 to 38) and 38 weeks (25 to 43) at delivery. During pregnancy, 85 women received ZDVm, and 225 women received combined ART; 245 (72%) women delivered by pre-labor caesarian section, 53 (16%) by emergency caesarian section and 38 (11%) vaginally. The cohort gave birth to 342 babies. Cumulative follow-up was 848 person-years with 1 death (combined ART-related lactic acidosis). Comparing ZDVm with combined ART:  At first antenatal screening, median CD4 were 462 vs 280 cells/mL (p = 0.001); median viral load 2067 vs 8236 copies/mL (p = 0.001). At last follow-up, median follow-up was 30 vs 34 months (p = 0.06); median CD4 510 vs 416 cells/mL (p = 0.02); CD4 < 200 cells/mL 6 of 85 (7%) vs 19 of 225 (8%) (p = 0.77); median viral 1886 vs 49 copies/mL (p = 0.23); 61% were on combined ART:  21 of 85 (25%) vs 168 of 225 (75%) (p < 0.0001). Of these 19 of 21 (90%) vs 141 of 168 (84%) had a viral load of < 50 copies/mL (p = 0.4); 8 patients had progressed to CDC C:  3 (3.5%) ZDVm vs 5 (2.2%) combined ART (mostly TB) (p = 0.5).

Conclusions:  With access to combined ART, 97% of mothers have AIDS progression-free survival after a mean of 33 months; 76% of pregnant women treated with ZDVm according to U.K. Guidelines have not yet needed combined ART and those who have were no less likely to suppress HIV replication. These data suggest that ZDVm initiated at 24 to 30 weeks for mothers with good CD4 counts and low viral load does not jeopardise their future therapy.

Keywords: maternal health; monotherapy; combination therapy