HIV-status disclosure may improve psychosocial health and adherence to antiretroviral therapy (ART), but existing insights suffer from methodological limitations. We explored disclosure over time during pregnancy and postpartum among 1347 HIV-positive women in Cape Town. Among 995 women diagnosed HIV-positive before the pregnancy and entering antenatal care (median age 30 years), 95% had disclosed to ≥ 1 individual. In Mokken scale analysis, we observed two separate dimensions of disclosure: disclosure to a male partner, and disclosure to family/community members. Among 352 women diagnosed during the pregnancy and initiating ART (median age 27 years), 61% disclosed to a male partner and 71% to a family/community member by 12 months after diagnosis. Relationship status modified the impact of pregnancy intentions and poverty on disclosure to a male partner. These unique data provide important insights into dimensions of disclosure during pregnancy and postpartum, and suggest that women’s social and economic circumstances are central determinants of disclosure.