Date of Defense:
September 30, 2009
Background: The Institute of Medicine’s (IOM’s) 2009 recommendations for gestational weight gain are the same for all women. Black women are more than twice as likely as white women to enter pregnancy overweight or obese; however, they gain less weight during pregnancy.
Objectives: To determine how black and white women with term births gained in comparison to the BMI-specific IOM recommendations by trimester.
Methods: We abstracted prenatal and delivery data from the records of a managed care organization and four community clinics. The sample included 2760 women aged 18 to 40 with measured baseline and prenatal weights, who had term, singleton pregnancies between 2004 and 2007. We examined the differences in trimester gains for black and white women with linear regression, adjusted for maternal age, height, body mass index (BMI), parity, prenatal tobacco use, infant sex, and weeks gestation at delivery. Trimester gains were compared to IOM recommendations with c2 -tests.
Results: Black women gained less in the first and second trimester among normal weight and obese women; overweight black women gained significantly less in all trimesters. At the end of the second trimester, more white (72%) than black (46%) overweight women exceeded IOM recommendations (p<0.0001). By the end of the third trimester, more white (80%) than black (65%) overweight women exceeded recommendations (p<0.0001). By the end of the third trimester, 69% of white and 56% of black obese women exceeded recommendations (p<0.002).
Conclusions: For both racial groups, risk of excessive gain begins by the second trimester, suggesting that education and application of guidelines should ideally begin in the first trimester.