title: Prepregnancy body mass index, vaginal inflammation, and the racial disparity in preterm birth.
abstract: The authors sought to quantify the overall and race/ethnic-specific relations between prepregnancy body mass index and both preterm birth and vaginal inflammation. Data from a cohort of 11,392 women who enrolled in the multicenter Vaginal Infections and Prematurity Study (1984-1989) at 23-26 weeks' gestation were used. Compared with a prepregnancy body mass index of 22, a body mass index of 16 increased the risk of preterm birth by 90% (odds ratio = 1.9, 95% confidence interval (CI): 1.5, 2.6), and a body mass index of 18 increased the risk by 40% (odds ratio = 1.4, 95% CI: 1.2, 1.7). Ethnicity substantially modified the magnitude of the body mass index effect and the shape of the preterm birth risk curve, with underweight having a greater impact on preterm birth among Blacks and Hispanics than among Whites. Low body mass index increased the risk of a high level of neutrophils (> 5 per oil immersion field) and a high vaginal pH measurement (> or = 5.0) among Black women; for a body mass index of 16 versus 22, the odds ratio = 1.7 (95% CI: 1.1, 2.6). Compared with Black women with a body mass index of 22, Blacks with a body mass index of 16 had a 1.7-fold increased risk for a high level of neutrophils and a high vaginal pH measurement, while those with a body mass index of 18 had a 1.3-fold increased risk.
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. hsimhan@mail.magee.edu
authors.forename: Hyagriv N
authors.initials: HN
authors.lastname: Simhan
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Bodnar
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D015992:Body Mass Index; D005260:Female; D005865:Gestational Age; D006630:Hispanic or Latino; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D016017:Odds Ratio; D011247:Pregnancy; D047928:Premature Birth / Q000208:ethnology* / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014627:Vaginitis / Q000150:complications* / Q000208:ethnology; D044465:White People