Barzilai University Medical Center

60 Research Day 2020 Barzilai University Medical Center 40 THE EFFECTS OF NIFEDIPINE ON ENDOTHELIAL FUNCTION IN PREGNANCY Leonti Grin 1 , Mark Rabinovich 1 , Eyal Y Anteby 1,3 , Chaim Yosefy 2,3 , Simon Shenhav 1,3 1 Department of Obstetrics and Gynecology, Barzilai University Medical Center, Ashkelon, Israel 2 Department of Cardiology, Barzilai University Medical Center, Ashkelon, Israel 3 Faculty of Health Studies, Ben Gurion University of the Negev, Beer Sheva, Israel Background Nifedipine is a calcium channel blocker (CCB) registered for the treatment of ischemic heart disease and hypertension. Albeit unlicensed for tocolysis, nifedipine is indicated by international guidelines as a first line tocolytic drug for women in threatened preterm labour (TPTL) in order to permit administration of glucocorticosteroids to promote fetal lung maturation. Hypothesis Nifedipine can potentially have an adverse effect on the endothelial function of blood vessels in pregnant women receiving it for acute tocolysis. Objectives To evaluate the endothelial function, using brachial artery reactivity test (BART) in patients treated with nifedipine for threatened preterm labour in the third trimester of pregnancy. Results We explored parameters of endothelial function in 22 pregnant women at a gestational age of 27–33 weeks with threatened preterm labor (TPTL) prior to versus 48 hours post nifedipine treatment. These women were treated with 80 mg nifedipine per day for 48 hours for tocolysis. Primary outcome was flow mediated vasodilation (FMD). Mean participants age was 27±5, Mean gestational age 29±4, BMI, kg/m 2 (mean±STD) 28.3±3.2. Systolic blood pressure (mmHg) and diastolic blood pressure (mmHg) both decreased after treatment with nifedipine (from 108±6 to 104±5, p<0.001) and (from 66±4 to 63±4, p<0.001), respectively. BART showed a significant decrease in FMD area (from 10.77 ± 6.96 to 7.73±5.91 %, p =0.04) before versus after nifedipine treatment. Brachial artery diameter (mm) at rest was (3.2 ±0.38 versus 3.35±0.49, p=0.26) before versus after nifedipine. Maximal brachial artery diameter (mm) after cuff deflation was (3.56 ±0.35 versus 3.59±0.41, p=0.76) before versus after nifedipine. Conclusions Our analysis revealed an unfavourable effect of nifedipine used for acute tocolysis on the endothelial function. Future studies should opt to evaluate the effects of maintenance nifedipine therapy on the endothelial function in pregnant women.