Table 1.
Participant characteristics for the 3 studies included in Mendelian randomisation analyses
| Characteristic | Category | ALSPAC (N = 7360) | BiB (N = 7433) | MoBa (N = 50,717) |
|---|---|---|---|---|
| Offspring | ||||
| CHD | Yes | 61 (0.8) | 81 (1.1) | 420 (0.8) |
| Sex | Male | 3703 (50.3) | 3818 (51.4) | 25,729 (51.0) |
| Female | 3657 (49.7) | 3615 (48.6) | 24,810 (49.0) | |
| Maternal | ||||
| Age, years | 29.2 (4.6) | 27.4 (5.6) | 30.2 (4.6) | |
| Parity | Primiparous | 3257 (46.6) | 2963 (40.1) | 27,199 (53.6) |
| BMI, kg/m2 | 22.5 (4.2) | 26.2 (5.7) | 24.1 (4.3) | |
| Ethnicity | White European | 7360 (100.0) a | 3084 (42.6) | 50,717 (100.0) b |
| South Asian | - | 3503 (48.4) | - | |
| Other | - | 656 (9.1) | - | |
| Any smoking during pregnancy | Yes | 1679 (26.1) | 1175 (18.1) | 4175 (10.1) |
| Any alcohol during pregnancy | Yes | 4866 (79.9) | 1040 (49.3) | 12,602 (32.6) |
Data are means ± SD or n (%) unless stated. % are based on data available (data were not complete)
Abbreviations: BiB, Born in Bradford; ALSPAC, Avon Longitudinal Study of Parents and Children; MoBa, Norwegian Mother, Father and Child Cohort Study; CHD, congenital heart disease; BMI, body mass index; kg, kilogrammes; m, metres
aAll non-white European women with ethnicity data were not included in the analysis
bIndividuals of non-European ancestries were removed based on principal component analysis