Abstract Body

Pregnancy and HIV both increase the risk of tuberculosis (TB) disease which results in poor maternal and infant outcomes. IMPAACT study P1078 found that isoniazid preventive therapy (IPT) during pregnancy resulted in a higher risk of adverse maternal and neonatal outcomes compared to IPT post-delivery, questioning the safety of IPT in pregnant women living with HIV (PWLHIV).

 

Tshepiso was a prospective cohort study evaluating maternal and infant outcomes among PWLHIV with and without active TB disease from January 2011 through January 2014 in Soweto, South Africa. Mother-infant pairs were followed through one year of life. Here we report the outcomes among PWLHIV without TB disease who reported initiating vs not initiating IPT during pregnancy. This was an observational study; IPT was initiated by public antenatal and HIV clinics and not by the study.

 

The Tshepiso study enrolled 155 PWLHIV without TB disease. This analysis includes 151 women with known pregnancy outcomes; 69 (46%) reported initiating IPT during pregnancy. The median age and CD4 T-cell count at enrollment was 30 years (IQR 27,31) and 364 cells/mm3 (IQR 252,464) for women on IPT vs 29 years (IQR 26,32) and 372 cells/mm3 (IQR 275,477) for women not on IPT. 63 (78%) and 43 (65%) women were on cART, 52 (83%) and 37 (86%) with EFV, respectively. Viral load during pregnancy was <400copies/mL in 60 (75%) women on IPT and 35 (52%) women not on IPT (p=0.004). The proportion of neonates born prematurely was lower in those exposed to IPT during pregnancy compared to unexposed (10% vs 22%; p=0.06). There was no difference in fetal demise (1% vs 1%; p=1.0), low birth weight (9% vs 12%; p=0.51), or congenital anomalies (1% vs 2%; p=1.0). A composite of the four outcomes (16% vs 28%; p=0.08) showed fewer events among infants exposed to IPT. Stratified analyses by viral load suppression did not demonstrate differences in pregnancy outcomes.

 

In this study, IPT use during pregnancy was not associated with a higher rate of poor maternal or infant outcomes. Though this study had well characterized exposures and outcomes, it was not designed to study the effect of IPT on pregnancy outcomes. IPT exposed and non-exposed PWLHIV may differ in factors associated with adverse outcomes in PWLHIV. More research is needed to evaluate the safety of IPT for PWLHIV given their high risk of TB disease and the poor maternal and infant outcomes associated with maternal TB/HIV co-infection, despite appropriate therapy.