Additional results for rs1229984 are presented in detail in Table 3. The strong evidence for association between this SNP and average intake before pregnancy but not during pregnancy, and the result showing that it predicts abstention in pregnancy but not before (Table 3), prompted us to investigate whether the variant was associated with the likelihood of drinking cessation in pregnancy. There is strong evidence that women carrying the rare A allele were more likely to quit alcohol during the first trimester of pregnancy [odds ratio (OR): 1.52; 95% confidence interval (CI): 1.22, 1.91; P-value = 0.0004) (Table 4). The evidence remains after adjusting for pre-pregnancy alcohol consumption (P-value = 0.004). Weaker evidence is found when looking at the odds of quitting at later stages of gestation, around week 18 and week 32, and these associations seem to be entirely explained by pre-pregnancy intake (Table 4).
