Are race and ethnicity risk factors for breech presentation?

Abstract

Objective: To investigate race and ethnicity as risk factors for breech presentation.

Design: Case-control study using a population-based birth certificate registry that included linkage to Medicaid/Women, Infants, & Children (WIC) eligibility data for a socioeconomic proxy variable.

Setting: Florida, USA.

Participants: 912,107 mothers of singletons born in Florida 1999 to 2003.

Methods: Maternal race and ethnicity were evaluated as risk factors for breech presentation using logistic regression. The dependent variable was birth presentation. Covariates were variable measures that have been repeatedly identified as risk factors for breech presentation in the literature and are known to be highly accurate birth certificate variable measures.

Results: White women were 69% more likely to have a breech baby (adjusted odds ratio [OR]=1.69, 95% confidence interval [CI] 1.63, 1.76) than Black women. Higher socioeconomic status was a risk factor in the bivariate analyses, but not in the adjusted analysis. Prematurity, nulliparity, female infant, and advancing maternal age were risk factors in the final model. The final model accounted for <5% of the total variance (Max Rescaled R(2)=4.18%), and thus was poorly fit (Hosmer and Lemeshow goodness of fit <0.0001).

Conclusions: White women were at increased risk of having a breech baby. However, important variables appear to be missing from the model.