We aimed to describe the prevalence of intimate partner violence (IPV) during pregnancy across 19 countries, and examine trends across age groups and UN regions. We conducted a secondary analysis of data from the Demographic and Health Surveys (20 surveys from 15 countries) and the International Violence Against Women Surveys (4 surveys from 4 countries) carried out between 1998 and 2007. Our data suggest that intimate partner violence during a pregnancy is a common experience. The prevalence of IPV during pregnancy ranged from approximately 2.0% in Australia, Cambodia, Denmark and the Philippines to 13.5% in Uganda among ever-pregnant, ever-partnered women; half of the surveys estimated prevalence to be between 3.9 and 8.7%. Prevalence appeared to be higher in African and Latin American countries relative to the European and Asian countries surveyed. In most settings, prevalence was relatively constant in the younger age groups (age 15-35), and then appeared to decline very slightly after age 35. Intimate partner violence during pregnancy is more common than some maternal health conditions routinely screened for in antenatal care. Global initiatives to reduce maternal mortality and improve maternal health must devote increased attention to violence against women, particularly violence during pregnancy.