​​​​Finding ways of preventing TB in pregnant and breast feeding women in the safest way possible for mom and baby was the objective of the study Prof Gerhard Theron presented at the Faculty of Medicine and Health Sciences' (FMHS) Annual Academic Day.

“There is a lack of data on isoniazid preventive therapy (IPT) during pregnancy. Pregnant women were excluded from previous randomised-controlled trials. The results of the study presented are vitally important because we need to know how to use IPT correctly during pregnancy and while breast feeding. These results will also inform the World Health Organisation (WHO) to develop guidelines," Theron said during his presentation entitled Randomized trial of safety of isoniazid preventive therapy during or after pregnancy. Theron is with the FMHS' Department of Obstetrics and Gynaecology.

The study was part of the International Maternal Paediatric Adolescent AIDS Clinical Trials (IMPAACT) Network P1078 phase IV. This multi-centre trial was conducted in 13 sites across eight countries, of which three were in South Africa, and involved 956 HIV-positive, pregnant women. The study evaluate the safety of immediate versus deferred IPT among HIV-infected women in high tuberculosis (TB) incidence settings. IPT is recommended to prevent active TB disease.  

The mothers were randomly assigned to receive 28 weeks of IPT either during pregnancy (immediate) or at 12 weeks after delivery (deferred). 

There was a low TB incidence in both the deferred and immediate groups. However, the results showed a statistically significant difference of adverse pregnancy outcomes between mother-infant pairs randomised to IPT during pregnancy and mother-infant pairs randomised to IPT after delivery, with more adverse outcomes among those who received the therapy during pregnancy. 

The study therefore showed that deferring IPT to after delivery may be advisable. Based on these results, the researchers concluded that WHO recommendation to initiate IPT during pregnancy in HIV-positive women on antiretroviral therapy may need re-evaluation.