The multivariable analyses adjusted for a wide range of factors that were potentially associated with the exposure and outcome, including paternal characteristics and postnatal factors such as maternal mental health and binge pattern of drinking. Furthermore, there was no adverse association between postnatal binge-pattern drinking (child aged 5 years) and outcomes, suggesting that risk related to intra-uterine exposure. In the analyses, we were also able to separate out the effects of frequency and quantity of drinking from binge-pattern drinking. This enabled us to achieve our aim of distinguishing risk related to occasional episodes of heavier drinking [36]. As the study utilised a population-based sample, few mothers (5 % of the sample) reported both daily drinking as well as episodic binge-pattern drinking which might have limited our ability to demonstrate an association involving this group. It is also possible that they spread their drinking over the course of the day when consuming ≥4 drinks and that their alcohol metabolising enzymes have been sufficiently induced because of their daily drinking pattern resulting in reduced fetal exposure to peak alcohol levels.
