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Table 2 Associations of maternal BMI with outcome risk factors, and of the genetic IVs (maternal non-transmitted alleles) with maternal BMI and outcome risk factors

From: Exploring the causal effect of maternal pregnancy adiposity on offspring adiposity: Mendelian randomisation using polygenic risk scores

  N SNPs R2maternal BMI Correlation with outcome risk factorsa
Parental occupation Maternal education Paternal education Maternal smoking Parity Paternal BMI Maternal age Paternal age
ALSPAC
N   5157 4807 4826 4572 4891 5042 3766 5157 3593
 Maternal BMIb    0.11*** − 0.12*** − 0.11*** − 0.01 0.06** 0.16*** 0.00c − 0.01c
 Genetic IV
  FTO 1 0.36% 0.03* − 0.01 − 0.01 0.00 0.02 − 0.01 − 0.01 0.00
  Speliotes 31 0.89% 0.02 0.00 − 0.03* − 0.01 0.02 0.01 0.00 0.01
  Locke 87 1.02% 0.03 − 0.01 − 0.04* − 0.01 0.03* 0.01 0.00 0.00
  Yengo 497 2.37% 0.04* − 0.04* − 0.05** 0.02 0.03 0.01 − 0.02 − 0.01
  Lassosum 80939 6.61% 0.08*** − 0.07*** − 0.08*** 0.07*** 0.02 0.03* − 0.08*** − 0.06**
BiB (SA)
N   2267 1689 2259 2258 2262 2215 475 2267 583
 Maternal BMIb    − 0.10** − 0.08** − 0.03 0.01 0.15*** 0.12* − 0.02c 0.02c
 Genetic IV
  FTO 1 0.77% − 0.01 − 0.01 0.00 − 0.03 0.00 0.00 0.02 0.06
  Speliotes 29 1.71% − 0.01 0.01 0.01 − 0.04 0.00 − 0.01 0.00 − 0.05
  Locke 82 1.33% − 0.04 0.02 0.03 − 0.05* − 0.01 − 0.06 0.00 0.02
  Yengo 446 1.64% − 0.04 − 0.04* 0.01 0.01 0.01 − 0.03 − 0.02 − 0.03
  Lassosum 79101 3.46% − 0.01 − 0.02 − 0.02 0.01 − 0.02 − 0.04 − 0.04 − 0.06
BiB (WE)
N   2000 1587 2000 1999 1999 1951 639 2000 788
 Maternal BMIb    − 0.09** − 0.07* 0.01 0.01 0.11*** 0.22*** 0.00c 0.04c
 Genetic IV
  FTO 1 0.56% 0.03 0.02 − 0.01 0.00 0.00 0.03 0.00 − 0.02
  Speliotes 31 0.92% 0.05 0.01 0.03 − 0.03 0.00 0.02 0.00 − 0.01
  Locke 86 1.16% 0.03 0.00 0.04 − 0.01 − 0.01 0.04 − 0.02 − 0.02
  Yengo 453 1.78% − 0.01 0.00 0.05* 0.01 0.00 0.00 − 0.03 0.00
  Lassosum 79101 5.21% − 0.08* − 0.05* 0.04 0.07* 0.04 0.03 − 0.07* 0.01
  1. aPearson correlation coefficients are presented here to give an indication of the direction and magnitude of associations; full regression results are presented in Additional file 1: Supplementary information S16–S19, * P < 0.05, ** P < 0.001, *** P < 1e−5. bAge-standardised z-scores for maternal BMI, as per the primary analyses. cMaternal BMI is not correlated with maternal or paternal age because it was age-standardised. SA South Asians, WE White Europeans, R2 proportion of maternal BMI variance explained by the IV (maternal non-transmitted allele scores), FTO rs9939609 at the FTO locus, Speliotes, Locke, Yengo PRS calculated from SNPs that reached genome-wide significance in the BMI GWAS with the indicated first author, Lassosum PRS calculated by the lassosum method