title: Preconception serum 1,1,1-trichloro-2,2,bis(p-chlorophenyl)ethane and B-vitamin status: independent and joint effects on women's reproductive outcomes.
abstract: BACKGROUND
  Although preconception 1,1,1-trichloro-2,2,bis(p-chlorophenyl)ethane (DDT) exposure and B-vitamin deficiencies have each been shown to negatively affect human reproductive outcomes, little is known about their joint effect.
  
  
  OBJECTIVE
  We sought to examine whether B-vitamin sufficiency protects against adverse effects of DDT on clinical pregnancy (CP) and subclinical early pregnancy loss (EPL).
  
  
  METHODS
  We measured preconception concentrations of plasma B vitamins (vitamin B-6, vitamin B-12, and folate) and serum total DDT [sum of p,p' and o,p' isomers of DDT and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] in 291 nulligravid women from Anhui, China, who were studied in 1996-1998. The women were followed prospectively from the time they stopped contraception until CP (gestational age ≥42 d) or 12 mo (whichever occurred first). EPL was identified by using daily urinary human chorionic gonadotropin. The women were categorized according to B-vitamin status (deficiency compared with sufficiency) and DDT concentration (high compared with low).
  
  
  RESULTS
  Of 291 study women, a total of 385 conceptions (31% of which ended in EPL) and 265 CPs occurred. Compared with women with adequate B-vitamins and low DDT, incidence rates of CP were reduced in women with B-vitamin deficiency and a high DDT concentration (P < 0.05 for all). Most notably, in women with sufficient vitamin B-12, DDT was not associated with the incidence of CP; in contrast, in women with vitamin B-12 deficiency, high DDT was associated with a lower incidence of CP (HR: 0.44; 95% CI: 0.23, 0.84); and the test for interaction was significant (P < 0.05). The odds of EPL decreased by 45% (95% CI: 21%, 62%) for each interquartile distance increase in folate in women with high DDT concentrations, and the test for interaction was significant (P = 0.006).
  
  
  CONCLUSIONS
  Our results provide suggestive evidence that vitamin B-12 and folate sufficiency may help protect against adverse reproductive effects of DDT exposure. Additional studies are needed to confirm our findings.
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Fengxiu
authors.initials: F
authors.lastname: Ouyang
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Longnecker
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Venners
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Sara
authors.initials: S
authors.lastname: Johnson
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Susan
authors.initials: S
authors.lastname: Korrick
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Xiping
authors.initials: X
authors.lastname: Xu
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Parul
authors.initials: P
authors.lastname: Christian
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Mei-Cheng
authors.initials: MC
authors.lastname: Wang
authors.affiliation: From the Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China (FO); the Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Department of Health and Human Services, Research Triangle Park, NC (MPL); the Simon Fraser University, Faculty of Health Sciences, Burnaby, Canada (SAV); the Division of General Pediatrics & Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (SJ and XW); the Department of Environmental Health, Harvard School of Public Health, Boston, MA (SK); the Shanghai Jiaotong University School of Public Health, Shanghai, China (JZ); the National Clinical Research Center of Kidney Disease; State Key Laboratory of Organ Failure Research; Nanfang Hospital, Southern Medical University, Guangzhou, China (XX); and the Departments of International Health (PC) and Biostatistics (M-CW) and Center on Early Life Origins of Disease, Department of Population, Family and Reproductive Health (XW), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D002681:China; D003634:DDT / Q000009:adverse effects / Q000097:blood*; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood; D005500:Follow-Up Studies; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D012098:Reproduction / Q000187:drug effects*; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000097:blood; D025101:Vitamin B 6 / Q000008:administration & dosage / Q000097:blood; D014803:Vitamin B Complex / Q000008:administration & dosage / Q000097:blood*; D014804:Vitamin B Deficiency / Q000097:blood*; D055815:Young Adult
chemical_list: D014803:Vitamin B Complex; D025101:Vitamin B 6; D005492:Folic Acid; D003634:DDT; D014805:Vitamin B 12
keywords: B vitamin; DDT; clinical pregnancy; early pregnancy loss; preconception