Proportions of facility births are increasing throughout sub-Saharan Africa, but obstetric services vary within the health system. In Tanzania, advanced management of childbirth complications ... Show moreProportions of facility births are increasing throughout sub-Saharan Africa, but obstetric services vary within the health system. In Tanzania, advanced management of childbirth complications (comprehensive emergency obstetric care) is offered in hospitals, while in frontline, primary health care (PHC) facilities (health centres and dispensaries) mostly only routine childbirth care is available. With over half (54%) of rural births in facilities, we hypothesized the presence of socio-economic inequity in hospital-based childbirth uptake in rural Tanzania and explored whether this relationship was modified by parity. This inequity may compound the burden of greater mortality among the poorest women and their babies. Records for 4456 rural women from the 2015-16 Tanzania Demographic and Health Survey with a live birth in the preceding 5years were examined. Proportions of births at each location (home/PHC/hospital) were calculated by demographic and obstetric characteristics. Multinomial logistic regression was used to obtain crude and adjusted odds ratios of home/PHC and hospital/PHC births based on household wealth, including interaction between wealth and parity. Post-estimation margins analysis was applied to estimate childbirth location by wealth and parity. Hospital-based childbirth uptake was inequitable. The gap between poorest and richest was less pronounced at first birth. Hospital-based care utilization was lowest (around 10%) among the poorest multiparous women, with no increase at high parity (>= 5) despite higher risk. PHC-based childbirth care was used by a consistent proportion of women after the first birth (range 30-51%). The poorest women utilized it at intermediate parity, but at parity >= 5 mostly gave birth at home. In an effort to provide effective childbirth care to all women, context-specific strategies are required to improve hospital-based care use, and poor, rural, high parity women are a particularly vulnerable group that requires specific attention. Improving childbirth care in PHC and strengthening referral linkages would benefit a considerable proportion of women. Show less