Does paternal alcohol consumption affect the severity of traits of fetal alcohol spectrum disorders?

Background: Animal models suggest that paternal alcohol consumption may influence offspring traits, yet few human studies exist.

Methods: Data from population-based studies of fetal alcohol spectrum disorders (FASD) among first-grade students provided case-control data to explore traits of fathers of children with: FASD, alcohol exposure, and unexposed controls.

Results: Most males in this population drank, but more fathers of children with FASD drank during pregnancy ( $\overline{x}$ = 73.2%) than fathers of controls ( $\overline{x}$ = 63.4%). Among drinkers, fathers of children with FASD: (a) consumed more drinks per occasion than controls ( $\overline{x}$ = 11.5 vs. 9.7 for maternally exposed controls and 8.1 for maternally unexposed controls), (b) drank more frequently and binged, and (c) were reported to have had a drinking problem ( $\overline{x}$ = 27.8% vs. $\overline{x}$ = 18.8%). Partial correlations, controlling for maternal average drinks per drinking day (DDD) by trimester and maternal tobacco use, indicated a significant, negative association between paternal heavy/binge drinking (≥5) and child outcomes resulting in a significant reduction in child height, head circumference, and verbal IQ. Categorical analysis of combined levels of maternal and paternal drinking indicated a significant mean reduction in child height, head circumference, and verbal IQ centile, and a significant increase in total dysmorphology score, did not occur without maternal drinking. Combined paternal and maternal drinking pattern analysis also indicated that paternal drinking was not independently associated with child total dysmorphology scores or neurocognitive outcomes. Models of maternal and paternal drinking were significant, but main and significant effects on total dysmorphology and neurocognitive outcomes were via maternal alcohol consumption. Likewise, paternal alcohol consumption was not independently associated with an FASD diagnosis when controlling for prenatal maternal alcohol and tobacco use.

Conclusions: Paternal alcohol consumption was associated with an independent, negative influence on child height, head circumference, and verbal IQ. Maternal drinking, when combined with heavy male drinking, was associated with more severe FASD outcomes.