The adequacy of prenatal care and incidence of low birthweight among the poor in Washington State and British Columbia

Objectives. The purpose of this study was to examine differences in adequacy of prenatal care and incidence of low birthweight between low- income women with Medicaid in Washington State and low-income women with Canadian provincial health insurance in British Columbia. Methods. A population-based cross-sectional study was done by using linked birth certificates and claims data. Results. Overall, the adjusted odds ratio for inadequate prenatal care in Washington (comparing women with Medicaid with those with private insurance) was 3.2. However, the risk varied by time of Medicaid enrollment relative to pregnancy (2.0, 1.0, 2.7, 6.3; for women who enrolled prior to pregnancy, during the first trimester, during the second trimester, or during the third trimester, respectively). In British Columbia, the adjusted odds ratio for inadequate care (comparing women receiving a health premium subsidy with those receiving no subsidy) was 1.5 for women receiving a 100% subsidy and 1.2 for women receiving a 95% subsidy. The risk for low birthweight followed a similar trend in both regions, but there was no association with enrollment period in Washington. Conclusions. Overall, the risk for inadequate prenatal care among poor women was much greater in Washington than in British Columbia. Most of the difference was due to Washington women's delayed enrollment in Medicaid. In both regions, the poor were at similar risk for low birthweight relative to their more affluent counterparts.