Longer maternal administration of zidovudine most effectively reduces mother-to-child HIV1 transmission and may allow for shorter administration in infants
- Newell, Marie-Louise MB MSc PhD
BACKGROUND
Long term zidovudine administration reduces mother-to-child HIV1 transmission. It is unknown whether shorter-term regimens have the same efficacy.
OBJECTIVE
To investigate the optimal duration for zidovudine administration in preventing mother-to-child HIV1 perinatal transmission.
SETTING
Twenty-seven clinics in Thailand; December 1998-May 2000.
METHOD
Randomised double-blind trial.
LITERATURE REVIEW
No explicit strategy; 16 references.
PARTICIPANTS
1437 HIV-positive pregnant women.
INTERVENTION
One 300 mg tablet of zidovudine was administered twice daily to mothers and 2 mg per kg body weight orally to infants every 6 hours in four different regimens: long maternal and baby; long maternal, short baby; short maternal, long baby; short maternal and baby. Short and long maternal regimens were from 35 and 28 weeks gestation, respectively. Short and long baby regimens were for 3 days or 6 weeks after birth, respectively. One 300 mg tablet was taken at the start of labour and repeated every 3 hours. Short groups received placebo for the remaining time.
OUTCOMES
HIV transmission rates at 18 month follow-up.
MAIN RESULTS
The short maternal and baby regimen was stopped after interim analysis showed a high rate of transmission (10.5%). The differences in transmission rates for the long-long, long-short and short-long regimens were not statistically significant. The combined in-utero transmission rate for both long maternal groups was 1.6%, compared with 5.1% for the combined short maternal groups (see Table 1). The relatively low rates of vertical transmission may be partly explained by the non-breastfeeding population used.
AUTHORS' CONCLUSIONS
Longer term maternal administration of zidovudine seems to be most effective at reducing mother-to-child HIV1 transmission. However, if the mother receives zidovudine from 28 weeks' gestation, it may not be necessary to treat the infant for more than 3 days after birth.