METHODS: We use data from Ghana\'s (2003, 2008 and 2014) and Nigeria\'s (2003, 2008 and 2013) Demographic and Health Surveys. We use concentration curves and concentration indices to measure the magnitude of socioeconomic-related inequalities and horizontal inequality in the use of reproductive health care services.
RESULTS: Exposure to family planning information via mass media, antenatal care at private facilities are more often used by women in wealthier households. Health worker\'s assistance during pregnancy outside a facility, antenatal care at government facilities, childbirth at home are more prevalent among women in poor households in both Ghana and Nigeria. Caesarean section is unequally spread to the disadvantage of women in poorer households in Ghana and Nigeria. In Nigeria, women in wealthier households have considerably more unmet needs for family planning than in Ghana. Country inequality was persistent over time and women in poorer households in Nigeria experienced changes that are more inequitable over the years.
CONCLUSIONS: We observe horizontal inequalities among women who use reproductive health care. These inequalities did not reduce substantially over the years. The gains made in reducing inequality in use of reproductive health care services are short-lived and erode over time, usually before the poorest population group can benefit. To reduce inequality in reproductive health care use, interventions should not only be pro-poor oriented, but they should also be sustainable and user-centered.