The safety of most antiretroviral agents to the foetus and infant has not been established thus narrowing the choice of ARV drug therapy to prevent MTCT during pregnancy, labor, delivery and the postpartum/postnatal/ Infant periods. There are, however various regimes of ARV therapy currently favored and available for prevention of mother to child transmission of HIV infection as shown in table 5.3. According to the 'American FDA Pregnancy Categories", Zidovudine (ZDC) and Nevirapine (NVP), are in class "C" in which safety in human pregnancy has not been determined, animal studies are either positive for foetal risk, or have not been conducted, and the drug should not be used unless the potential benefit outweighs the potential risk to the foetus".
TABLE 5.3 ANTI-RETROVIRAL THERAPY FOR REDUCTION/PREVENTION OF MCT
Breast Feeding Status |
Drug |
ANC |
Labour |
Baby |
% Reduction of MTCT |
Non breast feeding |
ZIDOVUDINE |
100mg p.o. 5 times daily from 14-34 wk gest. |
1.V 2.0mg/kg st, then 1 mg/kg/hr |
2mg/kg p.o. 6hrly x 6 wks |
68% (infection) status at 18 months) |
Non breast feeding |
ZIDOVUDINE |
300mg p.o o.d, from 36-40 from gest. |
300mg p.o, 3hrly |
No |
50% (infection status at 6 months age) |
Breast feeding |
NEVIRAPINE |
No |
200mg single dose at the onset of labour |
2mg/kg single dose in the first 72 hours |
47% (infection status at 6 weeks age) |
In our Kenyan set up, if one is to use The Thai Regime, it is advisable to start treatment at 34 weeks gestation since most of our patients deliver before 40 weeks gestation and they would not have had optimum therapy, if the therapy is started at 36 weeks. Details of further regimes recommended in preventing MTCT are provided in Appendix XT 11.
