The influence of nifedipine in pre-term labor therapy on blood flow parameters in fetal middle cerebral artery, umbilical artery and in maternal uterine arteries

The aim of this study was to evaluate the effect of nifedipine, drug that inhibits uterine contractions, on parameters of blood flow in the middle cerebral artery of the fetus and of the maternal placental circulation. Flow in the middle cerebral artery of the fetus, umbilical artery and uterine arteries of pregnant women and their fetuses with pre-term labor were analysed. The study included 70 pregnant women at gestational age between 26 and 36 week of pregnancy. Examination was performed in the supine position with elevation of the right side. Dose of nifedipine 3 × 10 mg was taken orally every 8 hours by the patients. The average values of vascular flow measurements before initiating therapy designed to stop premature uterine contractions and after an average of 14 hours of their inclusion, did not show significant changes. The main observed changes included the reduction in the rate of systolic and diastolic blood flow in the umbilical artery, and a growth of pulsatility index and the rate of systolic and diastolic blood flow in the left uterine artery. Nifedipine therapy during pre-term labor does not pose fetal risks. After determination of the optimal therapeutic dosage the drug can be prescribed according obstetric indications.