title: Dose-response relationship between alcohol consumption before and during pregnancy and the risks of low birthweight, preterm birth and small for gestational age (SGA)-a systematic review and meta-analyses.
abstract: BACKGROUND
  Descriptions of the effects of moderate alcohol consumption during pregnancy on adverse pregnancy outcomes have been inconsistent.
  
  
  OBJECTIVE
  To review systematically and perform meta-analyses on the effect of maternal alcohol exposure on the risk of low birthweight, preterm birth and small for gestational age (SGA).
  
  
  METHODS
  Using Medical Subject Headings, a literature search of MEDLINE, EMBASE, CINAHL, CABS, WHOlist, SIGLE, ETOH, and Web of Science between 1 January 1980 and 1 August 2009 was performed followed by manual searches.
  
  
  METHODS
  Case-control or cohort studies were assessed for quality (STROBE), 36 available studies were included.
  
  
  METHODS
  Two reviewers independently extracted the information on low birthweight, preterm birth and SGA using a standardised protocol. Meta-analyses on dose-response relationships were performed using linear as well as first-order and second-order fractional polynomial regressions to estimate best fitting curves to the data.
  
  
  RESULTS
  Compared with abstainers, the overall dose-response relationships for low birthweight and SGA showed no effect up to 10 g pure alcohol/day (an average of about 1 drink/day) and preterm birth showed no effect up to 18 g pure alcohol/day (an average of 1.5 drinks/day); thereafter, the relationship showed a monotonically increasing risk for increasing maternal alcohol consumption. Moderate consumption during pre-pregnancy was associated with reduced risks for all outcomes.
  
  
  CONCLUSIONS
  Dose-response relationship indicates that heavy alcohol consumption during pregnancy increases the risks of all three outcomes whereas light to moderate alcohol consumption shows no effect. Preventive measures during antenatal consultations should be initiated.
authors: Centre for Addiction and Mental Health, Toronto, ON, Canada. jayadeep_patra@camh.net
authors: J
authors: J
authors: Patra
authors: R
authors: R
authors: Bakker
authors: H
authors: H
authors: Irving
authors: V W V
authors: VW
authors: Jaddoe
authors: S
authors: S
authors: Malini
authors: J
authors: J
authors: Rehm
mesh_terms: D000428:Alcohol Drinking / Q000009:adverse effects* / Q000453:epidemiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology*; D012044:Regression Analysis; D012306:Risk; D012307:Risk Factors