Features of hemodynamics of the mother–placenta–fetus system in the first half of pregnancy after the assisted reproductive technologies application

Abstract

Doppler study is one of the main methods for assessing the condition of placental blood circulation and fetal hemodynamics. Doppler blood flow in the uterine arteries demonstrates the broad capabilities of the method for predicting pregnancy complications such as gestosis, fetal development delay, preterm birth, as well as for diagnosing adverse perinatal consequences. However, there is still no clear opinion about the feasibility of using Doppler as a screening test, as well as about the optimal pregnancy period for this type of study. The objective: is to study the hemodynamic features in pregnant women after assisted reproductive technologies (ART) application in the dynamics of the first part of pregnancy. Materials and methods. 299 pregnant women were examined – the main group included 249 women whose pregnancy occurred as a result of ART application. The control group consisted of 50 pregnant women with spontaneous pregnancy and its physiological course. I group – 94 women with tubal-peritoneal factor of infertility, II group – 87 women with endocrine factor of infertility, III group - 68 women whose infertility was caused by the male factor. Doppler ultrasound examination of the uterine arteries, arteries of the umbilical cord and middle cerebral arteries of the fetus were conducted. Results. It was found that the highest intensity of hemodynamics in the uterine artery basin at 11–12 weeks of gestation was recorded in a group of patients with a physiological course of pregnancy. The systolic-diastolic ratio in the right and left uterine arteries in these patients was 1.9 (1.8–2.7) and 2.1 (1.9–2.6), respectively. In contrast to women in the control group, pregnant women after ART application analyzed indicators were higher (1.6–1.9 times; p<0.0001). The systolic-diastolic ratio in the right uterine artery in III group was 3.0 (2.4–3.5), I group – 3.3 (3.1–3.4). Similar data were obtained analyzing the curves of blood flow rates in the left uterine artery – 2.9 (2.1–3.5) and 3.0 (2.7–3.6), respectively. The highest peripheral resistance, both in the right (3.6 (3.4–3.7) and left (3.5 (3.2–3.8) uterine arteries, was naturally registered in pregnant women of II group. In 36 (72%) patients with uncomplicated course and successful gestation at 11–12 weeks of pregnancy, blood flow was not recorded in the intervellon space. In the vast majority – 50 (73.5%) pregnant women of I group, two types of blood flow were registered in the intervellar space: pulsating arterial and continuous venous. Only in 18 (26.5%) patients of this group the blood flow in intervellon space was not determined. As a result of the obtained data analysis, it was found that at 16-17 weeks of gestation, the highest intensity of blood flow in the uterine artery pool was recorded in the control group. Thus, the systolic-diastolic ratio of the right and left uterine arteries in these subjects was 1.6 (1.5–1.8) and 1.8 (1.6–2.0). In pregnant women of the main group, the indicators were significantly higher (1.2-2.0 times; p<0.0001). The systolic-diastolic ratio in the uterine arteries in group III was 2,1 (1,9–2,6); 2,2 (1,9–2,5), in the II group – 3,1 (2,5–3,3); 2,2 (1,9–2,5), in the I group – 2,6 (2,5–3,2); 2,7 (2,5–2,9). In contrast to the control group, in which the systolic-diastolic ratio in the fetal umbilical artery was 3.4 (3.3–3.5), in III group patients, there was a significantly higher intensity of umbilical blood flow (S/D – 3.3 (3.5–3.6), p=0.03). At the same time, feto-placental hemodynamics in II and I groups patients was characterized by a significant increase in the numerical values of blood flow in the umbilical arteries (S/D – 4.5 (4.4–4.7), p=0.0001 and 3.5 (3.5–3.6), p=0.03, respectively). In patients of the control group, the systolic-diastolic ratio of the middle cerebral artery of the fetus at 16–17 weeks of gestation was 3.4 (3.4–3.5), almost completely coinciding with the same indicator in the umbilical artery (S/D – 3.4 (3.3–3.5). Patients of group III had a higher blood flow intensity, as evidenced by significantly lower (S/D 3.2 (3.1–3.3), compared with the control group (S/D 3.4 (3.4–3.5) absolute values of the systolic-diastolic ratio. An increase in the intensity of blood flow in the fetal medial artery (against the background of increased vascular resistance in the umbilical artery) was also recorded in the group of subjects of group II (S/D – 2.8 (2.7–2.9). High absolute values of systolic-diastolic ratio in the indicated vessel (4.4 (4.3–4.5) were found in the fetuses of the examined group and group, which characterize a significant decrease in the intensity of cerebral blood flow, compared with all the analyzed groups. Conclusions. Thus, the results of the study allow us to attribute Doppler ultrasound to highly informative research methods that make it possible to predict hemodynamic changes in the mother-placenta-fetus system, depending on the type of infertility, take preventive measures and start correction in time. Keywords: pregnancy, assisted reproductive technologies, Doppler ultrasound, uterine arteries, systolic-diastolic ratio.