Children born to mothers who drink alcohol during their pregnancy are more likely to have impaired cognitive abilities later in life, according to the findings of a systematic review in the International Journal of Epidemiology (29 January 2020)
The analysis of 23 studies also suggests that prenatal alcohol exposure may lead to lower birth weight.
The researchers incorporated five types of study design in their review to increase the reliability of the results. This included Mendelian randomisation, whereby a genetic variant is used as a proxy for alcohol exposure, and family-based designs, such as comparing children in the same family whose mother’s alcohol use changed between pregnancies.
The researchers concluded that there was moderately strong evidence that prenatal alcohol exposure had a negative effect on cognitive outcomes of children. This effect was ascertained with the use measures such as the Wechsler Intelligence Scale for Children, academic performance, and earnings later in life. However, there was weaker evidence that it could lead to lower birth weight.
They said their findings strengthened the evidence base for UK guidelines, which recommend that women abstain from drinking during pregnancy.
“This message is more important than ever, given recent research which shows the alcohol industry promoting confusing information about the real health implications of drinking during pregnancy,” said Luisa Zuccolo, senior lecturer in epidemiology at Bristol Medical School and lead researcher on the study.
 Mamluk L, Jones T, Ijaz S et al. Evidence of detrimental effects of prenatal alcohol exposure on offspring birthweight and neurodevelopment from a systematic review of quasi experimental studies. Int J Epidemiol 2020. doi: 10.1093/ije/dyz272