Table 10.
Hazard ratios for ADHD based on mothers with different patterns of variation in BMI
| BMI category |
No. of pairs | Difference in BMI | Entire populationa |
Full siblingsb |
|||
|---|---|---|---|---|---|---|---|
| First pregnancy | Second pregnancy | Mean (SD) | HR (95% CI) | P-value | HR (95% CI) | P-value | |
| Normal | Normal | 131 765 | 0.44 (1.24) | 1.02 (1.01–1.03) | 0.00 | 1.02 (0.98–1.06) | 0.30 |
| Normal | Overweight/obese | 25 317 | 2.96 (1.85) | 1.03 (1.01–1.06) | 0.01 | 1.03 (0.97–1.09) | 0.29 |
| Overweight/obese | Normal | 6589 | 2.47 (1.99) | 1.03 (0.98–1.08) | 0.31 | 0.98 (0.88–1.10) | 0.77 |
| Overweight/obese | Overweight/obese | 52 763 | 1.20 (2.25) | 1.05 (1.04–1.06) | 0.00 | 1.00 (0.97–1.03) | 0.92 |
a
Adjusted for offspring sex, birth order, year of birth, maternal age at delivery, smoking during pregnancy and cohabitation with child’s father at childbirth.
b
Adjusted for offspring sex, birth order, year of birth, maternal age at delivery, smoking during pregnancy and cohabitation with child’s father at childbirth, and shared familial confounding within full siblings.
ADHD, attention-deficit/hyperactivity disorder; SD, standard deviation; BMI, body mass index; HR, hazard ratio; CI, confidence interval.