Weight gain during early pregnancy
The pattern for early pregnancy weight gain showed similar results as those in total pregnancy: In normal-weight women, early GWG was 1.5±2.7 kg for PE, 0.7±1.6 kg for DVT, 1.3±2.4 kg for all VTE and 0.6±2.3 kg for control (Table S1), and did significantly differ between PE or all VTE and control group (adjusted estimated mean difference combined 0.03 kg, 95% CI 0-0.10 kg, p=0.0087 and 0.02 kg, 95% CI 0-0.08 kg, p=0.0235, respectively) (Table 2). There was observed protective effects of low weight gain (aOR 0.79; 95% CI 0.37–1.68) and significantly increased risks of high weight gain (aOR=1.47; 95% CI: 1.03-2.09) for PE in normal-weight women. As for underweight women, weight gain above average was associated with an increased risk of PE (aOR=2.50; 95% CI: 0.29-21.40), so was for overweight and obese women (aOR=2.13; 95% CI: 0.52-8.79), but estimates were not statistically significant. In contrast, associations of weight gain above or below average with DVT or all VTE were not significant, included the null (Table 4).