Effects of nifedipine on endothelial function, assessed by flow-mediated vasodilatation in pregnant patients

To evaluate the endothelial function, through flow-mediated vasodilation parameters from brachial artery test in women receiving nifedipine for acute tocolysis with threatened preterm delivery.

In a prospective study in a university-affiliated hospital, each participant served as herself control. We evaluated various parameters of endothelial function in 22 patients between 27 and 33 weeks of gestation with a diagnosis of threatened preterm delivery (TPTD) before and after 48 h of nifedipine treatment. Each patient received 80 mg nifedipine per day. The assessment tool was Brachial artery reactivity test (BART). Primary outcome was flow mediated vasodilation (FMD).

The average participant's age was 27 ± 4.5 years, median gestational age of 28.5 weeks, BMI, kg/m² (mean ± SD) 28.4 ± 3.3. Systolic blood pressure (mmHg) and diastolic blood pressure (mmHg) decreased from 108 ± 6 to 104 ± 5, p < .001 and from 66 ± 4 to 63 ± 4, p < .001, respectively. FMD (%) significantly decrease from 10.8 ± 6.1 to 7.2 ± 4.7, p = .03 prior to and after nifedipine treatment. The basal brachial artery diameter (mm) at rest was (3.19 ± 0.38 versus 3.39 ± 0.49, p = .28) before versus after nifedipine. The largest brachial artery diameter (mm) was (3.54 ± 0.35 versus 3.58 ± 0.44, p = .76) before versus after nifedipine.

Our results suggest unfavorable changes in FMD probably as a result of nifedipine used for acute tocolysis. Future prospective studies should try to evaluate the safety of acute and maintenance tocolytic therapy with nifedipine on endothelial function in pregnant women.