title: Risk of spontaneous abortion among women exposed to polybrominated biphenyls.
abstract: Accidental contamination of livestock in Michigan in 1973 with polybrominated biphenyls (PBBs) led to the establishment of a registry of exposed individuals in 1976. At the time of enrollment, serum was collected and analyzed for PBBs and polychlorinated biphenyls (PCBs). In 1997, women aged 18 years or older and active in the registry were invited to participate in a telephone interview about their health. Using generalized estimating equations to account for correlated outcomes within the same woman, we assessed the risk of spontaneous abortion among 529 women with 1344 potentially exposed pregnancies. PBB and PCB exposure were not associated with risk of spontaneous abortion after adjusting for maternal age at conception, age at menarche, and prior infertility. Compared to pregnancies with PBB exposure below the limit of detection, those with levels above 2.9 ppb had a non-significant reduced odds of spontaneous abortion (adjusted OR=0.73; 95% CI=0.47-1.13). Compared to pregnancies with PCB exposure below the limit of detection, those with levels above 6.5 ppb had little difference in risk (adjusted OR=0.91; 95% CI=0.59-1.41). Maternal age at conception above 34 years was significantly associated with elevated risk of spontaneous abortion (OR=2.46; 95% CI=1.10-5.49). The effect of prior infertility was of borderline significance (OR=1.52; 95% CI=0.98-2.38). Older age at menarche was associated with decreased risk of spontaneous abortion (adjusted OR=0.58; 95% CI: 0.38-0.89, comparing menarche at 12-13 with menarche <12). Our results do not support an association between exposure to PBBs or PCBs and risk of spontaneous abortion.
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA. csmall@sph.emory.edu
authors.forename: Chanley M
authors.initials: CM
authors.lastname: Small
authors.forename: Keely
authors.initials: K
authors.lastname: Cheslack-Postava
authors.forename: Metrecia
authors.initials: M
authors.lastname: Terrell
authors.forename: Heidi Michels
authors.initials: HM
authors.lastname: Blanck
authors.forename: Paige
authors.initials: P
authors.lastname: Tolbert
authors.forename: Carol
authors.initials: C
authors.lastname: Rubin
authors.forename: Alden
authors.initials: A
authors.lastname: Henderson
authors.forename: Michele
authors.initials: M
authors.lastname: Marcus
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology*; D000328:Adult; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D006801:Humans; D018811:Maternal Exposure; D008824:Michigan / Q000453:epidemiology; D011075:Polybrominated Biphenyls / Q000097:blood*; D011078:Polychlorinated Biphenyls / Q000097:blood*; D011247:Pregnancy; D012306:Risk
chemical_list: D004785:Environmental Pollutants; D011075:Polybrominated Biphenyls; D011078:Polychlorinated Biphenyls