• cumulative occurence of : -adverse pregnancy outcomes (spontaneous abortion, stillbirth, congenital abnormality requiring surgical correction in children < 1 yr of age); -paediatric HIV infection; -infant mortality [ Time Frame: at 6 and 12 months following delivery/birth ] [ Designated as safety issue: Yes ]
  

• occurence of grade 4 events in treated women, and of grade 3 or 4 events in ARV-exposed infants [ Time Frame: at 6 and 12 months following delivery/birth ] [ Designated as safety issue: Yes ]
  
• frequency of virological failure (>300 copies/mL) and viral resistance profile [ Time Frame: at 6 month and 12 months post-delivery ] [ Designated as safety issue: No ]
  
• frequency of premature delivery (<37 weeks) and frequency of low birth weight (<2500 g) [ Time Frame: at delivery/birth ] [ Designated as safety issue: Yes ]
  
• cumulative incidence of paediatric HIV infection [ Time Frame: at 12 months after delivery ] [ Designated as safety issue: No ]
  
• tolerability of the ARV combination in treated women [ Time Frame: at 6 and 12 months following delivery/birth ] [ Designated as safety issue: Yes ]
  

The prevention of MTCT during pregnancy and through breastfeeding exposure remains challenging to date in most resource-limited settings. Peripartum HIV transmission is already amenable to ARV interventions. These ARV regimens, partially efficacious are insufficiently used despite their apparent simplicity. The postnatal transmission via breastfeeding remains a serious additional threat.

This is a multicentric, non-inferiority, randomized controlled trial aiming at assessing the maternal and infant safety of a single daily fixed-dose combination of TDF/FTC/EFV (Atripla®), compared to the association of LPV/r (Kaletra® or Aluvia®) and 3TC/ZDV (Combivir®) given to African women (in Cote d'Ivoire an in Zambia) to prevent MTCT overall in breastfeeding population.

The fixed-dose combination of Tenofovir/Emtricitabine/Efavirenz (TDF/FTC/EFV or Atripla®) is a highly effective HAART combination and the simplest ARV regimen currently available in resource-limited settings and is therefore likely to become soon the lead first-line HAART regimen for adults in such settings. Its anticipated widespread prescription in women of childbearing age requires the proper documentation of its use in pregnancy and during breastfeeding.

The combination of ZDV/3TC (Combivir®) and Lopinavir/ritonavir (LPV/r) (Kaletra® or Aluvia®) is chosen as a reference regimen as it is one of the most commonly used first-line HAART for adults and the reference regimen for PMTCT in industrialised settings.

The maternal ARV regimen will be initiated as soon as possible from 20 weeks of gestation until at least the cessation of breastfeeding (with the advice to cease at six months). The decision to stop or continue the maternal ARV regimen after breastfeeding cessation will be based on the baseline maternal CD4 count and the maternal clinical stage at baseline and/or at breastfeeding cessation. A woman with a baseline CD4 <500 cells/ml will always be proposed to continue her treatment after breastfeeding cessation. A woman with a baseline CD4 count >500 will be asked to stop her treatment after breastfeeding cessation unless she has reached the WHO clinical stage IV at that time.

Infants will receive daily Zidovudine syrup from birth during the first week of life, or an updated ARV post-exposure prophylaxis recommended by WHO when women receive HAART.