Safety of nifedipine in threatened preterm labor: Investigation by three‐dimensional echocardiography

Abstract

According to RT3DTTE measurements, in pregnant women treated with nifedipine for tocolysis, there were no detrimental cardiovascular effects detected 48 hours postnifedipine treatment. RT3DTTE could show accurately the compensatory response of the left heart to the cardiovascular changes induced by treatment with nifedipine.

Maternal and fetal parameters in pregnant woman undergoing tocolysis with nifedipine

“…Studies suggest that a reduction in the blood pressure may occur in normotensive pregnant women who underwent tocolysis with nifedipine, however, often without any symptoms or clinical repercussions. 21,22 There is a report on a patient using nifedipine, who developed a severe hypotension. 13 While, other studies have not shown a decrease in the blood pressure levels, 12,23,24 which may be due to a wide methodological variety and of doses used.…”

“…17 The effects of nifedipine described in the literature in another population, is controversial, in normotensive pregnant women. 21 Several studies have addressed the effects of nifedipine on the uteroplacental flow in pregnant women inhibiting labor with nifedipine, but the results are quite controversial. 6,12,[15][16][17]21,23,24,28 In a study carried out with 28 pregnant women who underwent tocolysis with nifedipine evaluated the blood flow of the umbilical, uterine and fetal middle cerebral arteries using velocimetric doppler parameters and the atrioventricular valves in the first 48 hours of therapy.…”

“…21 Several studies have addressed the effects of nifedipine on the uteroplacental flow in pregnant women inhibiting labor with nifedipine, but the results are quite controversial. 6,12,[15][16][17]21,23,24,28 In a study carried out with 28 pregnant women who underwent tocolysis with nifedipine evaluated the blood flow of the umbilical, uterine and fetal middle cerebral arteries using velocimetric doppler parameters and the atrioventricular valves in the first 48 hours of therapy. It was found that after 24 hours of tocolytic treatment with nifedipine, there was a reduction in the pulsatility index in the uterine and fetal middle cerebral artery, which may influence the perfusion of the fetal side of the placenta, 16 similar to a study conducted with 49 pregnant women who underwent the same treatment.…”

“…17 In our study, we also observed that the MHR increased significantly (p=0.03), however, when the analysis was made between the hours, there was a tendency to increase the MHR, when compared to the baseline measurement within the 24 hours, similar to other studies found in the literature, in which no significant differences were observed, before and after the use of nifedipine for tocolysis. 6,12,[15][16][17]21,23,24,28 This may be due to the methodological differences among the studies, since none of them had any comparisons among various moments, in addition to this tendency increased the MHR may have been a compensatory response to a decrease in the blood pressure. 21 It is noteworthy that our study was the only one found in the researched literature, in which there was a longer follow-up time, up to 72 hours, and multiple comparisons.…”

“…6,12,[15][16][17]21,23,24,28 This may be due to the methodological differences among the studies, since none of them had any comparisons among various moments, in addition to this tendency increased the MHR may have been a compensatory response to a decrease in the blood pressure. 21 It is noteworthy that our study was the only one found in the researched literature, in which there was a longer follow-up time, up to 72 hours, and multiple comparisons. However, according to cardiac physiological hemodynamics , it is to be expected that the decrease in systemic blood pressure will lead to an increase in heart rate.…”