title: Neonatal outcomes of intrauterine nonylphenol exposure--a longitudinal cohort study in Taiwan.
abstract: BACKGROUND
  Nonylphenol (NP) is an environmental hormone with proven estrogenic effects. Although its adverse effects on animals are well documented, the effects of NP exposure on humans remain unclear, and those on the human foetus are completely unknown. This study explores the effects of intrauterine NP exposure on neonates.
  
  
  METHODS
  A cohort of pregnant women was established in a medical centre in northern Taiwan. Urine samples from the first, second, and third trimesters of gestation were collected. Urinary NP concentration was measured by high-performance liquid chromatography coupled with fluorescent detection. Neonatal outcomes were evaluated immediately after delivery. A mixed-effects model using a generalised estimating equation was applied to assess the association between gestational age, maternal body weight, and maternal NP concentration throughout the three trimesters. A multivariable regression model was used to determine the association between maternal NP level in urine in each trimester and neonatal outcomes.
  
  
  RESULTS
  In total, 162 singleton pregnant women completed this study through delivery. The geometric mean of creatinine-adjusted urinary NP concentrations were 4.27 μg/g, 4.21 μg/g, and 4.10 μg/g in the first, second, and third trimesters, respectively. Pregnant women whose urinary NP concentrations were above the median in the second trimester had low maternal weight gain (β=-1.55 kg, p=0.02) and short neonatal body length (β=-0.47 cm, p=0.04). Women with an above-median urinary NP concentration had an odds ratio of having a small for gestational age (SGA) neonate of 7.81 (p<0.05).
  
  
  CONCLUSIONS
  This study indicates that maternal high NP exposure in the second trimester is associated with SGA, decreased foetal body length at birth, and low maternal weight gain. The effects of this endocrine-disrupting substance on pregnant women and foetuses should be a concern during gestation.
authors.affiliation: Department of OBS & GYN, Cathay General Hospital, Taipei, Taiwan.
authors.forename: Ming-Song
authors.initials: MS
authors.lastname: Tsai
authors.forename: Chia-Huang
authors.initials: CH
authors.lastname: Chang
authors.forename: Yen-An
authors.initials: YA
authors.lastname: Tsai
authors.forename: Kai-Wei
authors.initials: KW
authors.lastname: Liao
authors.forename: I-Fang
authors.initials: IF
authors.lastname: Mao
authors.forename: Tzu-Hao
authors.initials: TH
authors.lastname: Wang
authors.forename: Shiaw-Min
authors.initials: SM
authors.lastname: Hwang
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Chang
authors.forename: Mei-Lien
authors.initials: ML
authors.lastname: Chen
mesh_terms: D049628:Body Size; D002851:Chromatography, High Pressure Liquid; D015331:Cohort Studies; D052244:Endocrine Disruptors / Q000633:toxicity* / Q000652:urine; D005260:Female; D005333:Fetus / Q000187:drug effects*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D015233:Models, Statistical; D010636:Phenols / Q000633:toxicity* / Q000652:urine; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*; D012044:Regression Analysis; D013624:Taiwan
chemical_list: D052244:Endocrine Disruptors; D010636:Phenols; C025256:nonylphenol