Table 2. Overall risk for GDM in second pregnancy by interpregnancy change in BMI (n = 24,198), The Medical Birth Registry of Norway 2006–2014.
| Interpregnancy BMI Change (kg/m2) |
RR for GDM in Second Pregnancy |
|||||
|---|---|---|---|---|---|---|
| Total | GDM /1000 | Crude RR |
95% CI | aRR* | 95% CI | |
| <−2 | 15/1,692 | 8.9 | 0.8 | 0.5–1.4 | 0.9 | 0.5–1.6 |
| −2 til <−1 | 34/2,384 | 14.3 | 1.3 | 0.9–1.9 | 1.3 | 0.9–2.0 |
| −1 til <1 | 126/11,512 | 10.9 | 1.0 | Reference | 1.0 | Reference |
| 1 til <2 | 79/3,814 | 20.7 | 1.9 | 1.4–2.5 | 2.0 | 1.5–2.7 |
| 2 til <4 | 97/3,279 | 29.6 | 2.7 | 2.1–3.5 | 2.6 | 2.0–3.5 |
| ≥4 | 88/1,517 | 58.0 | 5.3 | 4.1–6.9 | 5.4 | 4.0–7.4 |
| Total | 439/24,198 | 18.1 | 24,198 | 20,824 | ||
a, adjusted; BMI, Body Mass Index; GDM, Gestational Diabetes Mellitus; RR, relative risk.
*Analysis adjusted for maternal age during the second pregnancy (<25 (reference), 25–29, 30–34, ≥35 years), maternal country of birth (Nordic [reference]/non-Nordic), maternal education (<11, 11–13, ≥14 [reference] years), smoking in pregnancy (no[reference],/yes), interpregnancy interval (<12, 12–23 [reference], 24–35, ≥36 months), and year of the second birth (continuous).