Figure 1: Joint association of parental BMI on infant birthweight.
The effect of the interaction is illustrated by varying maternal (A & B ) and paternal BMI (C & D ) with the other parental BMI set at 20 and 35 kg/m2respectively. Grey circles are observed birth weights. Solid red lines are the median model estimates, dashed lines are 10thand 90th percentiles and dotted lines are the 5th and 95th percentile models. 95% confidence intervals (blue bars) are presented for parental BMIs of 20 kg/m2, 27.5 kg/m2 and 35 kg/m2. These estimates are for IVF insemination, vaginal births and female babies and have other continuous covariates set at their median values.