title: Association of selected persistent organic pollutants in the placenta with the risk of neural tube defects.
abstract: Persistent organic pollutants (POPs) have been associated with a wide range of adverse health effects. Our case-control study was performed to explore the association between placental levels of selected POPs and risks for neural tube defects (NTDs) in a Chinese population with a high prevalence of NTDs. Cases included 80 fetuses or newborns with NTDs, whereas the controls were 50 healthy, nonmalformed newborn infants. Placental concentrations of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers were analyzed by gas chromatography-mass spectrometry. The medians of PAHs, o,p'-isomers of dichlorodiphenyltrichloroethane (DDT) and metabolites, α- and γ-hexachlorocyclohexane (HCH), and α-endosulfan were significantly higher in case placentas than in controls. PAH concentrations above the median were associated with a 4.52-fold [95% confidence interval (CI), 2.10-9.74) increased risk for any NTDs, and 5.84- (95% CI, 2.28-14.96) and 3.71-fold (95% CI, 1.57-8.79) increased risks for anencephaly and spina bifida, respectively. A dose-response relationship was observed between PAH levels and the risk of NTDs, with odds ratios for the second, third, and fourth quartiles, compared with the first, of 1.77- (95% CI, 0.66-4.76), 3.83- (95% CI, 1.37-10.75), and 11.67-fold (95% CI, 3.28-41.49), respectively. A dose-response relationship was observed for anencephaly and spina bifida subtypes. Similar results were observed for o,p'-DDT and metabolites, α-HCH, γ-HCH, and α-endosulfan, whereas no dose-response relationship was observed for the last two pollutants. Elevated placental concentrations of PAHs, o,p'-DDT and metabolites, and α-HCH were associated with increased risks of NTDs in this population.
authors.affiliation: Institute of Reproductive and Child Health and Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing 100191, China. renag@bjmu.edu.cn
authors.forename: Aiguo
authors.initials: A
authors.lastname: Ren
authors.forename: Xinghua
authors.initials: X
authors.lastname: Qiu
authors.forename: Lei
authors.initials: L
authors.lastname: Jin
authors.forename: Jin
authors.initials: J
authors.lastname: Ma
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Li
authors.forename: Le
authors.initials: L
authors.lastname: Zhang
authors.forename: Huiping
authors.initials: H
authors.lastname: Zhu
authors.forename: Richard H
authors.initials: RH
authors.lastname: Finnell
authors.forename: Tong
authors.initials: T
authors.lastname: Zhu
mesh_terms: D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D003634:DDT / Q000032:analysis; D004726:Endosulfan / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis*; D062665:Epidemiological Monitoring; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D055768:Halogenated Diphenyl Ethers / Q000032:analysis; D001556:Hexachlorocyclohexane / Q000032:analysis; D006801:Humans; D007231:Infant, Newborn; D018811:Maternal Exposure / Q000009:adverse effects; D009436:Neural Tube Defects / Q000453:epidemiology* / Q000209:etiology; D010575:Pesticides / Q000032:analysis; D010920:Placenta / Q000737:chemistry*; D011078:Polychlorinated Biphenyls / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D004785:Environmental Pollutants; D055768:Halogenated Diphenyl Ethers; D010575:Pesticides; D011084:Polycyclic Aromatic Hydrocarbons; C040534:alpha-hexachlorocyclohexane; D001556:Hexachlorocyclohexane; D003634:DDT; C016340:o,p'-DDT; D011078:Polychlorinated Biphenyls; D004726:Endosulfan