Prevention of perinatal transmission 

Zidovudine alone, started at 14-34 weeks of gestation and continued in the infant for the first 6 weeks of life, reduced HIV transmission from 26% to 8%. Zidovudine alone taken orally for just 3-4 weeks before delivery and during labor has been reported to decrease the risk of HIV transmission by 50%. Most clinicians now would give combination therapy with zidovudine plus another NRTI and either a protease inhibitor or nevirapine throughout pregnancy to prevent transmission of HIV to the offspring. Women not already on therapy should consider waiting until after 10-12 weeks of gestation to begin.