Table 4

Estimated indirect effects of maternal and paternal prepregnancy obesity on offspring IQ assessed at a mean age of 8.6 years through pathways involving gestational weight gain, birth weight and duration of breastfeeding, Avon Longitudinal Study of Parents and Children

MediatorIndirect effects of parental prepregnancy obesity on offspring IQ
Full-scale IQVerbal IQPerformance IQ
Complete case analysis
(n=2976)		All cases
(n=4324)		Complete case analysis (n=2976)All cases
(n=4324)		Complete case analysis (n=2976)All cases
(n=4324)
Beta coefficient95% CI*Beta coefficient95% CI*Beta coefficient95% CI*Beta coefficient95% CI*Beta coefficient95% CI*Beta coefficient95% CI*
Gestational weight gain
 Maternal obesity−0.49−0.92 to −0.15−0.47−0.85 to −0.14−0.38−0.80 to −0.02−0.38−0.72 to −0.07−0.48−0.92 to −0.13−0.45−0.87 to −0.09
 Paternal obesity−0.02−0.17 to 0.14−0.04−0.15 to 0.06−0.02−0.14 to 0.11−0.03−0.13 to 0.05−0.02−0.17 to 0.14−0.03−0.15 to 0.06
Birth weight
 Maternal obesity0.29−0.05 to 0.700.270.01 to 0.550.23−0.04 to 0.560.210.01 to 0.470.29−0.05 to 0.710.270.02 to 0.56
 Paternal obesity0.20−0.08 to 0.490.15−0.01 to 0.320.16−0.06 to 0.400.12−0.01 to 0.270.20−0.07 to 0.490.15−0.01 to 0.33
Breastfeeding duration
 Maternal obesity−0.02−0.06 to −0.004–†–†−0.03−0.06 to −0.005–†–†−0.02−0.04 to −0.002–†–†
 Paternal obesity−0.01−0.04 to 0.008–†–†−0.01−0.04 to 0.009–†–†−0.007−0.02 to 0.005–†–†

  • Models were mutually adjusted for parental body mass index categories as well as child’s sex, maternal age at delivery, parity, marital status during pregnancy, pre-existing hypertension, any smoking during pregnancy, index of alcohol consumption during pregnancy and index of socioeconomic status. More details on these variables can be found in online supplementary table S1.

  • Referent: Maternal body mass index of 18.5 to <25 for maternal obesity; paternal body mass index of 18.5 to <25 for paternal obesity.

  • *1000 bootstrapped samples.

  • †Counterfactual effects not available for this model.