WASHINGTON – Adherence to gestational weight gain recommendations and prepregnancy body mass index varies significantly depending on race and ethnicity, Erica Holland reported.
In addition, black women were at the greatest risk of prepregnancy overweight or obesity while Asian women were at the greatest risk of being underweight. Meanwhile, the majority of black, white, and Hispanic women overgained weight during pregnancy.
When adjusted for age, marital status, and several other factors, Asian, black, and Hispanic women had significantly decreased odds of gaining excessive weight compared with white women, even though the majority of black and Hispanic women gained weight excessively during pregnancy, according to study results presented at the annual meeting of the American College of Obstetricians and Gynecologists.
Black women were 1.56 times more likely to be overweight and 1.61 times more likely to be obese prior to pregnancy than their white counterparts. Hispanic women were 1.28 times more likely to be overweight, and 1.23 times more likely to be obese compared with white women. Asian women were 2.25 times more likely to be underweight and less likely to be overweight or obese compared with their white counterparts.
The findings have opened the door for further research on maternal and neonatal outcomes based on race and ethnicity and on gestational weight gain (GWG) adherence, which could in turn change recommendations, said Ms. Holland, a third-year medical student at the University of Massachusetts, Worcester, who presented the study findings.
She speculated that the variation could be caused by various factors such as cultural differences, maybe a genetic component, and disparities in weight gain advice given to women based on their race.
Evidence suggests GWG nonadherence is a risk factor for adverse birth outcomes. The Institute of Medicine updated its recommendations for GWG in 2009, giving a range based on the mother’s body mass index (BMI). Women at a normal weight for their height (BMI of 18.5-24.9) should gain 25-35 pounds during pregnancy, underweight women (BMI less than 18.5) should gain 28-40 pounds, and overweight women (BMI of 25-29.9) should gain 15-25 pounds, according to the 2009 IOM guidelines. The recommendations, however, are not tailored based on race and ethnicity, Ms. Holland said in her presentation.
To find the association of race and ethnicity with prepregnancy BMI and GWG adherence, researchers conducted a retrospective study using automated labor and delivery records of 11,992 women with a mean age of 29 years. In total, 70% of the women were multigravida, 69% were white, 18% Hispanic, 9% black, and 5% Asian; 91% of the women delivered full-term.
In total, 3.8% of the population was underweight and 21% were obese before pregnancy. A quarter gained weight properly during pregnancy, said Ms. Holland, but 68% overgained weight during pregnancy.
Prior to pregnancy, 2% of black women were underweight, 39% were normal weight, and 59% were overweight or obese. The statistics were, respectively, 3%, 51%, and 46% for white women; 9%, 73%, and 18% for Asian women; and 5%, 47%, and 48% for Hispanic women.
For GWG, 20% of black women undergained, 27% appropriately gained and 54% over gained. The statistics were 15%, 26%, and 60% for white women; 22%, 38%, and 41% for Asian women; and 20%, 27%, and 54% for Hispanic women.
Ms. Holland said that while both undergaining and overgaining are risk factors for adverse birth outcomes, overgaining has been more prevalent due the obesity epidemic.
"As mounting evidence suggests that GWG nonadherence is a risk for adverse birth outcomes, appropriate counseling and interventions to optimize gain are proving more important. Further study is needed to understand how recommendations can be tailored to meet specific needs of different racial/ethnic groups," she said.
Ms. Holland said she had no relevant financial disclosures.