Comparing Perinatal Outcome in Twin and Singleton Pregnancies Regarding Doppler Evaluation of Uterine Artery Indices in the Second Trimester

Background: Prediction of adverse perinatal and postnatal outcomes could be possible by using ultrasound Doppler evaluation, however there are some controversies regarding this issue in the literature. The goal of present study was to evaluate predictive value of Doppler indices in single and twin pregnancies during second trimester. Materials and Methods: This prospective study was conducted in Yas Hospital, Tehran, between February 2015 and January 2016. The number of 71 singleton pregnancies and 59 twin pregnancies enrolled in this study. A single expert perinatalogist / sonographer did all Doppler ultrasound exams and followed up cases until the end of pregnancy. To compare Doppler indices and pre-postnatal outcomes between singleton and twin groups, the Student's t-test, Pearson chi 2 test and Fisher's exact test were used for continue and categorical variables, respectively. Results: Rates of preterm delivery and SGA were significantly higher in twin pregnancies compared with singletons (P<0.001). Mean PI in singleton pregnancies was significantly higher than in twin pregnancies (1.4 +/- 0.8 vs. 0.6 +/- 0.2; P<0.001). On the other hand mean RI in twin pregnancies was significantly higher than the counterpart group (0.8 +/- 0.4, 0.6 +/- 0.2; p=0.002). Doppler ultrasound indices were not significantly different in singleton and twin pregnancies with and without complications (P>0.05). Conclusion According the results, the mean PI of uterine arteries in twin pregnancies in the second trimester was significantly lower than singleton pregnancies. On the other hand this value did not differ between perinatal complicated and uncomplicated pregnancies.