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1.5 million HIV-positive pregnant women give birth every year, 91% of whom reside in sub-Saharan Africa, the region which also has the highest rates of neonatal and child morbidity and mortality. Antiretroviral therapy (ART)-naïve maternal HIV-infection is associated with an increased risk of preterm birth (<37 weeks), small-for-gestational-age (<10th centile), low birthweight (<2500g) and stillbirth. ART in pregnancy reduces maternal morbidity and mortality, and greatly reduces mother-to-child transmission of HIV, but may increase the risk of adverse perinatal outcomes.

In 2013-2016 we conducted a prospective pregnancy cohort study in Soweto, South Africa. Uniquely, for all 663 enrolled women, gestational age was estimated by first-trimester ultrasound and birthweight measured within 24 hours of birth. Detailed information on ~200 items was collected, including sociodemographic characteristics; smoking, alcohol and illicit drug use; nutritional supplements; drug history; medical and obstetric history, and detailed information on maternal HIV and ART. Enrolled women received ultrasound scans every 5 weeks to monitor fetal growth.

Key references:

  • Wedi et al Hemelaar, Lancet HIV,3:e33-48(2016).
  • Santosa et al Hemelaar, AIDS, 33:1623-33(2019).


The project will encompass analysis of the detailed data set of the extremely well-characterised pregnant South African women in our cohort. Fetal growth velocity will be compared between HIV-positive and HIV-negative women. Univariable and multivariable analyses will examine risk factors associated with specific perinatal outcomes, in both HIV-positive and HIV-negative women. Correlations and overlap between adverse perinatal outcomes, such as preterm birth and small for gestational age, will be assessed in HIV-positive and HIV-negative women. In addition, maternal outcomes will be assessed in both groups of women.

New data collection in South Africa may be possible in the future, depending on the evolving COVID situation. This would allow analysis of perinatal outcomes in the context of the new dolutegravir-based ART regimen which has been introduced since our previous study concluded. This would allow comparison of outcomes among HIV-positive women receiving efavirenz-based ART and dolutegravir-based ART.


It is anticipated that the main work will be conducted in Oxford and all necessary facilities, equipment and training, including study design, analytic and statistical training, will be provided in Oxford. New data collection in South Africa may be possible in the future.


A student with a background in medicine, obstetrics & gynaecology, infectious diseases, statistics or global health might suit this project. A successful candidate will have experience in and an enthusiasm for complex data sets and statistical modelling. The project has a broad scope and candidates are encouraged to contact Dr Joris Hemelaar to work out a specific project proposal.