In sub-Saharan Africa, an estimated 22.5 million people live with human immunodeficiency virus type 1 (HIV-1) infection.1 In the province of KwaZulu-Natal, the prevalence of HIV-1 infection is estimated to be 39% among women who attend antenatal clinics.2 Poor socioeconomic conditions, sexual networking, multiple concurrent partnerships, low level of condom use and high rates of sexually-transmitted infections are factors that contribute to the high local prevalence of HIV-1 infection.2,3 Trials for the prevention of HIV-1 infection have been heavily focused on developing biomedical interventions under female control.4–6 Typically these trials recruit sexually active, non-pregnant women of childbearing age and, since the teratogenic effects of the products they test are seldom known, the women are required to use an effective birth control method. Furthermore, if a trial participant falls pregnant, she is usually taken off the product under study, a practice that reduces the trial’s statistical power and its ability to demonstrate the product’s efficacy.