Association of CYP1A1 rs2472297, AHR rs6968865 and combined SNP score with total caffeine consumption (mg).

Caffeine consumption (mg) calculated as the sum of number of cups of tea and coffee, and drinks of cola, per day, weighted by approximate caffeine content. Time reflects data collected during pregnancy at 8, 18 and 32 weeks gestation and 2, 47, 85, 97 and 145 months after delivery. Beta reflects the number of drinks per day per T allele. Combined Score reflects the number of T alleles summed across SNPs rs2472297 and rs6968865.