The Superobese Mother and Ethnic Disparities in Preterm Birth

Objectives We assessed the association between preterm birth and obesity subtypes across racial/ethnic groups. Methods We analyzed data on 540 981 women from birth cohort files for the State of Florida from 2004 to 2007. Obese women were categorized using body mass index (BMI) values as class I obese (30.0 ≤ BMI ≤ 34.9), class II obese (35.0 ≤ BMI ≤ 39.9), class III or extremely obese (40 ≤ BMI ≤ 49.9), and superobese (BMI ≥ 50.0). Logistic regression was used to obtain adjusted estimates. Results About 28% of women were obese, with the highest rate (40.9%) registered among black gravidas, while whites and Hispanics had comparable rates (24.3% vs 25.5%, respectively). Superobesity was also most prevalent in blacks (1.3%). Among obese women, the risk for preterm birth was greatest among blacks (OR, 1.71; 95% CI, 1.65-1.77), while whites (OR, 1.15; 95% CI, 1.12-1.19) and Hispanics (OR, 1.22; 95% CI, 1.18-1.27) had significantly lower and comparable risk levels. Conclusions Extremely obese and superobese women are emerging high-risk groups for adverse birth outcomes, and black women appear to bear the heaviest burden. The disproportionately rising trend in extreme forms of obesity among black women is of utmost concern and represents a clarion call for infusion of more resources into obesity prevention programs in black communities.