Superimposed pre-eclampsia (SPE) can be resolved only with the termination of the pregnancy. Therefore, the risk prediction and prevention is very important. We aimed to evaluate the characteristics of patients who develop SPE and their controllable risk factors during mid-trimester.Design and method:
Total 283 pregnant women (33 ± 4.0 years old) with chronic hypertension (CHT) were included for the study. Blood pressure (BP) and body weight were recorded at 10, 20, 24, 28 and 32 week of gestation. And pregnancy outcomes were compared by the development of SPE.Results:
75 women (26.5%) finally developed SPE. There were no significant differences of maternal age (p = 0.287), obesity (p = 0.441), body weight (p = 0.080) before the pregnancy, and the prevalence of multiple pregnancy (p = 0.359) between patients with and without SPE. BPs were not different by the development of SPE before 20 week of gestation, however systolic and diastolic BP significantly increased in patients who finally developed SPE after 24 week of gestation compared to who did not developed SPE (at 24 week, SBP 132.9 ± 11.5 mmHg vs 140.0 ± 17.1 mmHg, p < 0.001; DBP 82.6 ± 9.5 mmHg vs 86.9 ± 12.7 mmHg, p = 0.005) and SBP at 24 week predicted SPE with the area under the curve (AUC) of 0.622 by receiver operating characteristic curve. Body weight was not significantly different throughout pregnancy, however, patients developed SPE showed greater weight gain during mid-trimester (4.9 ± 2.6 kg vs 5.9 ± 2.2 kg, p = 0.014) and predicted SPE with the AUC of 0. 610. Patients with SPE showed more frequent preterm labor (p < 0.001), intrauterine growth restriction (p < 0.001) and lower birth weight (p < 0.001), but not placenta abruption (0.668).Conclusions:
The development of SPE was more prevalent in women who showed higher BP at 24 week and greater weight gain during mid-trimester. More intensive monitoring of patients with higher BP and proper body weight control during mid-trimester may improve the prognosis of the pregnancy by decreasing the development of SPE.