Introduction: According to the WHO, miscarriage is defined as “the loss of a pregnancy before the age of 20 weeks of gestation or fetal weight below 500 g”. Only 50–60% of all conceptions fail to survive 20 weeks of gestation. It is estimated that about 75% of all unsuccessful conceptions are due to failed implantation and are not reported as spontaneous abortions.
Material and Methods: We performed a prospective observational study at the Department of Obstetrics and Gynecology of the Medical University Plovdiv between October 2014 and September 2015. We studied two groups of pregnant women: women with threatened abortion and those with normal pregnancy. All women underwent a transvaginal ultrasound evaluation of the uterine arterial blood flow. We measured peak systolic and end-diastolic velocity and calculated the average IR (resistance index) and S / D (systolic to diastolic ratio).
Results: There was no association between pregnancy outcome and the mean difference between uterine arterial IR and S / (P > 0.05).
Conclusion: In our study, Doppler ultrasound could not differentiate between women at risk for miscarriage and normal women. Further studies are necessary to answer this question.
