Kayo Takahashi1, Akihide Ohkuchi2, Hirotada Suzuki1, Rie Usui1, Tomoyuki Kuwata1, Koumei Shirasuna3, Shigeki Matsubara1, Mitsuaki Suzuki1. 1. Department of Obstetrics and Gynecology, Jichi Medical University School of Medicine, Tochigi, Japan. 2. Department of Obstetrics and Gynecology, Jichi Medical University School of Medicine, Tochigi, Japan. Electronic address: okuchi@jichi.ac.jp. 3. Division of Inflammation Research, Center of Molecular Medicine, Jichi Medical University, Tochigi, Japan.
Abstract
OBJECTIVES: We evaluated the biological interaction between blood pressure (BP) and uterine artery Doppler (UAD) in the second trimester for early-onset preeclampsia (EO-PE) risk. STUDY DESIGN: A prospective cohort study. MAIN OUTCOME MEASURES: In 2410 pregnant women, mean pulsatility index (mPI) and mean notch depth index (mNDI) were examined by UAD at 16-23weeks' gestation. We defined EO-PE as PE with onset at <34weeks, abnormal UAD as coexistence of mPI⩾90th percentile and mNDI⩾90th percentile, and high BP as systolic BP/diastolic BP⩾120/80mmHg. Abnormal UAD and high BP were combined as a series of dummy variables, and were entered into a logistic regression model. The relative excess risk due to biological interaction (RERI) was calculated using the following equation: RERI=odds ratio (OR) in women with both high BP and abnormal UAD - OR in women with high BP alone - OR in women with abnormal UAD alone +1. RERI⩾10 was considered as strong. RESULTS: EO-PE and late-onset PE (LO-PE) occurred in 1.1% and 1.2%, respectively. Adjusted odds ratio (95% CI) in women with abnormal UAD alone, high BP alone, and both high BP and abnormal UAD for predicting EO-PE was 4.3 (0.37-49), 12 (2.6-55) and 85 (17-422), respectively; and that for predicting LO-PE was 6.3 (1.5-27), 6.1 (2.1-17) and 15 (3.6-61), respectively. The RERI for EO-PE and LO-PE was 70 and 3.3, respectively. CONCLUSION: High BP and abnormal UAD may have a strong biological interaction for the occurrence of EO-PE.
OBJECTIVES: We evaluated the biological interaction between blood pressure (BP) and uterine artery Doppler (UAD) in the second trimester for early-onset preeclampsia (EO-PE) risk. STUDY DESIGN: A prospective cohort study. MAIN OUTCOME MEASURES: In 2410 pregnant women, mean pulsatility index (mPI) and mean notch depth index (mNDI) were examined by UAD at 16-23weeks' gestation. We defined EO-PE as PE with onset at <34weeks, abnormal UAD as coexistence of mPI⩾90th percentile and mNDI⩾90th percentile, and high BP as systolic BP/diastolic BP⩾120/80mmHg. Abnormal UAD and high BP were combined as a series of dummy variables, and were entered into a logistic regression model. The relative excess risk due to biological interaction (RERI) was calculated using the following equation: RERI=odds ratio (OR) in women with both high BP and abnormal UAD - OR in women with high BP alone - OR in women with abnormal UAD alone +1. RERI⩾10 was considered as strong. RESULTS:EO-PE and late-onset PE (LO-PE) occurred in 1.1% and 1.2%, respectively. Adjusted odds ratio (95% CI) in women with abnormal UAD alone, high BP alone, and both high BP and abnormal UAD for predicting EO-PE was 4.3 (0.37-49), 12 (2.6-55) and 85 (17-422), respectively; and that for predicting LO-PE was 6.3 (1.5-27), 6.1 (2.1-17) and 15 (3.6-61), respectively. The RERI for EO-PE and LO-PE was 70 and 3.3, respectively. CONCLUSION: High BP and abnormal UAD may have a strong biological interaction for the occurrence of EO-PE.