Introduction: Inadequate trophoblastic invasion of spiral arteries is associated with intrauterine growth retardation, pregnancy induced hypertension, preeclampsia, and abruptio placentae. The ability to accurately identify pregnant women who will develop these complications is limited. Predictive tests are further challenged by difficulty in the timing of the measurements, because the structural and biochemical characteristics of the placenta change with increasing gestational age. Improvements in ultrasound technology provide potentially useful novel tools for evaluating placental structure.
Aim of our study: To develop methods for early screening of high-risk pregnancies (studying the circulation in the utero-placental arteries — impedance to flow).
Material and methods: We have followed-up pregnant women in their first and second trimesters, who presented for pregnancy care in our unit. Results were calculated using Student-test and Chi-test (for the presence or absence of prothodiastholic notch). Results: Impedance to flow and the frequency of the prothodiastholic notch decrease in the uterine arteries with the evolution of pregnancy. Changes in the resistance of uterine arteries during pregnancy show different patterns in certain obstetrical risk groups: obesity, smoking in pregnancy, uterus with previous interventions (scar from C-section) with the placenta on the anterior wall, pregnancies with „Vanishing Twin Syndrome”. In these groups we noticed a greater resistance in the uterine arteries.
Conclusions: These pregnancies should have an intensified follow-up.