title: Neural tube defects and associated low birth weight.
abstract: OBJECTIVE
  To estimate the association between neural tube defects (NTDs) and low birth weight.
  
  
  METHODS
  This was a retrospective cohort study of women undergoing ultrasound from 17 to 22 weeks from 1990 to 2008. Presence or absence of fetal NTD defined the two study groups. The primary outcomes were intrauterine growth restriction (IUGR), birth weight <10th percentile, and severe IUGR <5th percentile. Subgroup analysis was performed to observe if the association with IUGR persisted.
  
  
  RESULTS
  Of 66,956 women, 170 were found to have fetal NTD. Only the rate of advanced maternal age differed between the study groups. Fetuses with an NTD were at significantly increased risk for IUGR <10th percentile (adjusted odds ratio [aOR] 2.6, 95% confidence interval [CI] 1.8 to 3.9) and <5th percentile (aOR 2.8, 95% CI 1.9 to 4.3). The association persisted in subgroup analyses.
  
  
  CONCLUSIONS
  Fetuses with NTD are at increased risk for IUGR, suggesting that a policy of serial growth scans in cases with isolated NTD is justified.
authors.affiliation: Department of Obstetrics and Gynecology, Washington University School of Medicine in St. Louis, St. Louis, MO 63130, USA. normans@wudosis.wustl.edu
authors.forename: Shayna M
authors.initials: SM
authors.lastname: Norman
authors.forename: Anthony O
authors.initials: AO
authors.lastname: Odibo
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Longman
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Roehl
authors.forename: George A
authors.initials: GA
authors.lastname: Macones
authors.forename: Alison G
authors.initials: AG
authors.lastname: Cahill
mesh_terms: D000328:Adult; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005317:Fetal Growth Retardation / Q000209:etiology*; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008423:Maternal Age; D009436:Neural Tube Defects / Q000150:complications* / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D012307:Risk Factors; D014463:Ultrasonography