The relationship of immigration documentation status and prenatal care adequacy with birth outcomes among Hispanic women in the US

Background: While one of the goals of Healthy People 2010 is to have 90% of pregnant women initiate prenatal care in the first trimester of pregnancy, there is an intense debate surrounding the issue of public funding of medical care for undocumented immigrants.  Yet undocumented immigrants often lack access to basic medical services and thus are more likely to have no or inadequate prenatal care (PNC). Previous studies have shown that immigrants have improved obstetric outcomes compared to US born residents, but less is known about differences between documented and undocumented immigrants and the impact of access to medical services on obstetric outcomes.

Methods: Using a cross-sectional review of 2005 Texas birth certificate data, we evaluated the interaction between PNC adequacy, measured by the Kotelchuck index, and immigration documentation status with low birthweight and preterm birth among Hispanic women living in selected Texas counties. Documentation status was identified by the presence of a maternal Social Security Number on the birth certificate.  Logistic regression analysis was used to control for confounding variables.

Results: Undocumented Hispanic immigrants had the highest rates of inadequate prenatal care and inadequate prenatal care was associated with higher rates of preterm birth and low birth weight among all ethnicities. However, inadequate prenatal care was less detrimental for undocumented Hispanic immigrants, as compared to documented Hispanics, and especially for women living closer to the Mexican border.    Conclusions:  Poor access to prenatal care is associated with adverse birth outcomes in all ethnicities, although the effects are weakest for undocumented Hispanics.  The interaction between birth outcomes, ethnicity, and proximity to the Mexican border may reflect lifestyle differences of women living on the border or greater access to both Mexican and U.S. services.