Table 2.
Relevance and strength of the genetic risk scores with exposures in pregnancy
| Study | N participants | N SNPs in GRS | Coefficient (95% CI)a | P-value | R2/pseudo R2 b | F statistic c | AUC |
|---|---|---|---|---|---|---|---|
| Association of GRS for BMI with pre-/early-pregnancy BMI | |||||||
| ALSPAC | 6253 | 941 | 0.24 (0.21, 0.26) | 1 × 10−80 | 5.6% | 372 | - |
| BiB | 6196 | 939 | 0.20 (0.18, 0.23) | 5 × 10−59 | 4.1% | 268 | - |
| MoBa | 45,033 | 868 | 0.25 (0.24, 0.26) | < 1 × 10−100 | 6.3% | 3,023 | - |
| Association of GRS for a lifetime smoking index with any smoking during pregnancy | |||||||
| ALSPAC | 6428 | 126 | 1.27 (1.20, 1.35) | 1 × 10−16 | 1.6% | - | 0.56 |
| BiB | 6482 | 126 | 1.36 (1.27, 1.45) | 2 × 10−20 | 2.2% | - | 0.59 |
| MoBa | 41,292 | 119 | 1.27 (1.23, 1.31) | 5 × 10−47 | 1.0% | - | 0.57 |
| Association of GRS for drinks per week with any alcohol consumption in pregnancy | |||||||
| ALSPAC | 6087 | 98 | 1.14 (1.07, 1.21) | 3 × 10−5 | 0.4% | - | 0.53 |
| BiB | 2110 | 99 | 1.08 (0.99, 1.18) | 0.09 | 0.2% | - | 0.52 |
| MoBa | 38,645 | 73 | 1.02 (0.99, 1.04) | 0.17 | 0.007% | - | 0.50 |
| MoBa sensitivity d | 38,645 | 73 | 1.05 (1.02, 1.08) | 0.003 | 0.04% | - | 0.51 |
Abbreviations: SNP Single nucleotide polymorphism, GRS Genetic risk score, CI Confidence interval, AUC Area under the curve, ALSPAC Avon Longitudinal Study of Parents and Children, BiB Born in Bradford, MoBa Norwegian Mother, Father and Child Cohort
aEffect estimates (coefficient) are difference in mean (BMI) or odds ratio (smoking or drinking yes/no during pregnancy) per SD increase in genetic risk score
bFor the binary outcomes (smoking and alcohol) pseudo-R2 are presented
cFor BMI F-statistic is presented; for binary outcomes (smoking and alcohol) AUC is presented
dIn MoBa 32% consumed any alcohol during pregnancy. However, 63% of those consumed alcohol “less than once per month” based on the questionnaire data. In the sensitivity analysis shown above, we re-coded the variable so that those that consumed alcohol less than once per month were classed as non-drinkers (N.B. due to the small numbers in each individual category, we were not able to analyse these separately). This was performed as an additional check to ensure the GRS was associated with pregnancy alcohol consumption in MoBa