Comparison of effects of nifedipine and ritodrine on maternal and fetal blood flow patterns in preterm labor.

OBJECTIVE The aim of this study was to investigate and compare the effects of nifedipine and ritodrine treatment on fetomaternal blood flow parameters in women with preterm labor. MATERIAL AND METHODS Sixty women with gestational age between 24 and 36 weeks admitted to the obstetrics clinic for preterm labor were enrolled in this study. Patients were randomly assigned to receive either nifedipine (n=30) or ritodrine (n=30) treatment. Demographic features, clinic and laboratory parameters, fetal and maternal side effects, and Doppler ultrasound indices of the umbilical artery (UA), uterine arteries (UtA), and middle cerebral artery (MCA) before, 2 hours after, and 48 hours after the initiation of tocolytic treatments were compared between the two groups. RESULTS In both the groups, early- and late-onset changes in the pulsatility index (PI) and other Doppler indices for UA, UtA, and MCA were similar. In addition, time elapsed till delivery, fetal mortality, and maternal morbidity in both the groups were not statistically significant (p>0.05). However, maternal side effects such as tachycardia was more frequent (p<0.05) in the ritodrine group. Besides, in the ritodrine group, anxiety was only minimally observed. CONCLUSION Nifedipine and ritodrine used as tocolytic agents did not significantly alter early- and late-onset changes in Doppler ultrasonography parameters in fetal and fetomaternal circulation.