title: Body Mass Index as a Measure of Obesity: Racial Differences in Predictive Value for Health Parameters During Pregnancy.
abstract: As a measure of obesity, body mass index (BMI; kg/m2) is an imperfect predictor of health outcomes, particularly among African Americans. However, BMI is used to guide prenatal care. We examined racial differences in the predictive value of maternal BMI for physiologic correlates of obesity, serum interleukin (IL)-6 and C-reactive protein (CRP), as well as cesarean section and infant birth weight.
  
  
  
  One hundred five pregnant women (40 European American, 65 African American) were assessed during the second trimester. BMI was defined as per prepregnancy weight. Electrochemiluminescence and enzyme-linked immunosorbent assays were used to quantify IL-6 and CRP, respectively. Birth outcomes were determined by medical record review.
  
  
  
  Women of both races classified as obese had higher serum IL-6 and CRP than their normal-weight counterparts (ps ≤ 0.01). However, among women with overweight, elevations in IL-6 (p < 0.01) and CRP (p = 0.06) were observed among European Americans, but not African Americans (ps ≥ 0.61). Maternal obesity was a significantly better predictor of cesarean section among European Americans versus African Americans (p = 0.03) and BMI was associated with infant birth weight among European Americans (p < 0.01), but not African Americans (p = 0.94). Effects remained after controlling for gestational age at delivery, gestational diabetes, and gestational weight gain as appropriate.
  
  
  
  BMI may be a less valid predictor of correlates of overweight/obesity among African Americans versus European Americans during pregnancy. This should be considered in epidemiological studies of maternal-child health. In addition, studies examining the comparative validity of alternative/complementary measures to define obesity in pregnancy are warranted to inform clinical care.
authors.affiliation: 1 College of Nursing, The Ohio State University , Columbus, Ohio.
authors.forename: Shannon L
authors.initials: SL
authors.lastname: Gillespie
authors.affiliation: 2 Department of Psychiatry and Behavioral Health, The Ohio State University Wexner Medical Center , Columbus, Ohio.|3 Department of Obstetrics and Gynecology, The Ohio State University Wexner Medical Center , Columbus, Ohio.|4 The Institute for Behavioral Medicine Research, The Ohio State University Wexner Medical Center , Columbus, Ohio.|5 Department of Psychology, The Ohio State University , Columbus, Ohio.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Christian
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D001724:Birth Weight; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D002585:Cesarean Section / Q000706:statistics & numerical data*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D054624:Health Status Disparities; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D049449:Luminescence; D009765:Obesity / Q000150:complications / Q000208:ethnology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data*
chemical_list: D015850:Interleukin-6; D002097:C-Reactive Protein
keywords: birth weight; cesarean section; health status disparities; inflammation; obesity; pregnancy