title: Maternal sleep deprivation is a risk factor for small for gestational age: a cohort study.
abstract: OBJECTIVE
  To determine trimester-specific risk factors for small-for-gestational-age (SGA) infants.
  
  
  METHODS
  A population-based prospective cohort study was conducted in Sri Lanka from May 2001 to April 2002. Pregnant women were recruited on or before 16 weeks of gestation and followed up until delivery. The sample size was 690. Trimester-specific exposure status and potential confounding factors were gathered on average at 12th, 28th and 36th weeks of gestation. SGA was assessed using customised birth centile charts. Multiple logistic regression was applied, and the results were expressed as odds ratios (OR) and 95% confidence intervals (95%CI).
  
  
  RESULTS
  The risk factors for SGA less than 5th centile were shift work and exposure to physical and chemical hazards during 2nd and 3rd trimesters (OR 4.20, 95%CI 1.10-16.0), sleeping for less than or equal to 8 h during 2nd or 3rd or both trimesters (OR 2.23, 95%CI 1.08-4.59), walking for less than or equal to 2.5 h per day (OR 2.66, 95%CI 1.12-6.31) and alcohol consumption during the 3rd trimester (OR 14.5, 95%CI 2.23-94.7). Poor weekly gestational weight gain was significantly associated with both SGA < 10th and < 5th centiles. None of the other factors became significant for SGA < 10th centile.
  
  
  CONCLUSIONS
  Risk factors for SGA less than 5th centile were sleep deprivation and shift work and exposure to physical and chemical hazards during 2nd and 3rd trimesters, less walking hours and alcohol consumption during 3rd trimester. Poor weekly gestational weight gain may be considered as a predictor of delivering an SGA infant.
authors.affiliation: Department of Public Health, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka. chrishanthaabeysena@yahoo.com
authors.forename: Chrishantha
authors.initials: C
authors.lastname: Abeysena
authors.forename: Pushpa
authors.initials: P
authors.lastname: Jayawardana
authors.forename: Rohini
authors.initials: R
authors.lastname: DE A Seneviratne
mesh_terms: D015331:Cohort Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology* / Q000209:etiology; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000502:physiology*; D016015:Logistic Models; D018811:Maternal Exposure / Q000009:adverse effects; D007752:Obstetric Labor, Premature / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011256:Pregnancy Outcome; D011264:Pregnancy Trimesters; D011446:Prospective Studies; D012307:Risk Factors; D012892:Sleep Deprivation / Q000453:epidemiology* / Q000523:psychology; D013188:Sri Lanka / Q000453:epidemiology; D013315:Stress, Psychological / Q000453:epidemiology / Q000523:psychology*