Extreme obesity and risk of stillbirth among black and white gravidas.
OBJECTIVE
To estimate the risk for stillbirth among three generally accepted obesity subtypes based on severity.


METHODS
We used the Missouri maternally linked cohort data containing births from 1978 to 1997. Using prepregnancy weight and height, mothers were classified on the basis of calculated body mass index (BMI) above 30 into three subsets: class I (30-34.9), class II (35-39.9), and extreme obesity (greater than or equal to 40). Using normal-weight, white women (18.5-24.9) as a reference, we applied Cox proportional hazard regression models to estimate risks for stillbirth.


RESULTS
The prevalence of obesity in pregnant women was 9.5% (12.8% among blacks and 8.9% among whites). Overall, obese mothers were about 40% more likely to experience stillbirth compared with nonobese gravidas (adjusted hazard ratio 1.4; 95% confidence interval [CI] 1.3-1.5). The risk for stillbirth increased in a dose-dependent fashion with increase in BMI: class I (adjusted hazard ratio 1.3; 95% CI 1.2-1.4); class II (adjusted hazard ratio 1.4; 95% CI 1.3-1.6) and extreme obesity (adjusted hazard ratio 1.9; 95% CI 1.6-2.1; P for trend <.01). Obese black mothers experienced more stillbirths than their white counterparts (adjusted hazard ratio 1.9; 95% CI 1.7-2.1 compared with adjusted hazard ratio 1.4; 95% CI 1.3-1.5). The black disadvantage in stillbirth widened with increase in BMI, with the greatest difference observed among extremely obese black mothers (adjusted hazard ratio 2.3; 95% CI 1.8-2.9).


CONCLUSIONS
Obesity is a risk factor for stillbirth, particularly among extremely obese, black mothers. Strategies to reduce black-white disparities in birth outcomes should consider targeting obese, black women.


METHODS
II.
Salihu
Hamisu M
HM
Department of Epidemiology, University of South Florida, Tampa, Florida, USA. hamisu.salihu@gmail.com
Dunlop
Anne-Lang
AL
Hedayatzadeh
Maryam
M
Alio
Amina P
AP
Kirby
Russell S
RS
Alexander
Greg R
GR
D000328:Adult; D001741:Black or African American / Q000208:ethnology; D044383:Black People / Q000235:genetics; D015992:Body Mass Index; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008923:Missouri / Q000453:epidemiology; D009767:Obesity, Morbid / Q000150:complications* / Q000453:epidemiology; D016017:Odds Ratio; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology* / Q000235:genetics; D016016:Proportional Hazards Models; D012307:Risk Factors; D012720:Severity of Illness Index; D050497:Stillbirth / Q000453:epidemiology* / Q000235:genetics; D044465:White People / Q000235:genetics