Objectives: To describe predictors of pregnancy and changes in pregnancy incidence among HIV-positive women accessing HIV clinical care. Design: Data were obtained through the linkage of two separate studies: the UK Collaborative HIV Cohort study (UK CHIC), a cohort of adults attending 13 large HIV clinics; and the National Study of HIV in Pregnancy and Childhood (NSHPC), a national surveillance study of HIV-positive pregnant women. Pregnancy incidence was measured using the proportion of women in UK CHIC with a pregnancy reported to NSHPC. Generalized estimating equations were used to identify predictors of pregnancy and assess changes in pregnancy incidence in 2000-2009. Results: The number of women accessing care at UK CHIC sites increased as did the number of pregnancies. Older women were less likely to have a pregnancy [adjusted relative rate (aRR) 0.44 per 10 year increment in age, [95% confidence interval (CI) (0.41-0.46)], P