Clinical assessment of the placenta function in women at risk and threat of premature delivery

Abstract

Premature birth, despite the significant achievements of perinatal medicine in recent decades, remains an urgent global and national medical and social problem, as it is the leading cause of perinatal morbidity and mortality. According to modern views, placental dysfunction can be one of the causes of premature birth, and its frequency, according to randomized studies, can be from 78 to 91%, depending on the gestational age. At the same time, the research conducted to date does not provide a clear understanding of the role of timely diagnosis and prevention of placental dysfunction in preventing premature birth.The objective: to perform clinical evaluation of the prevalence of placental dysfunction in women at risk of preterm birth and with threat of preterm birth.Materials and methods. 180 pregnant women were took part in the study. To achieve the research aim, three research groups were formed. I group – 73 pregnant women with threat of premature birth; II group – 77 pregnant women with risk factors for premature birth. Women with risk factors for premature birth were included in the study at the stage of pregnancy planning (IIA subgroup, 39 women) or from the moment of applying to a women’s outpatient clinic to monitor the course of pregnancy (IIB subgroup, 38 pregnant women). The control group included 30 pregnant women with an uncomplicated course of pregnancy.Transabdominal ultrasound examination with color Doppler mapping, determination of free estriol, progesterone and placental lactogen levels in blood serum were performed at 18–21+6 and 28–30 weeks of gestation.Results. Analysis of the prevalence of risk factors for placental dysfunction and preterm birth in patients of the studied cohort showed that in pregnant women with preterm birth (I group), the combination of risk factors was 5.2; in pregnant women who received pre-gravid training (IIA subgroup) – 3.2; in pregnant women who were included in the study in the I trimester of pregnancy (IIB subgroup) – 4.7, while in pregnant women of the control group – only 0.8 (p<0.05).The threat of early spontaneous miscarriage with the formation of a retrochorial hematoma as a clinical manifestation of primary placental dysfunction was determined in 43.8% of pregnant women whose premature delivery was carried out for medical reasons. Placenta abruption in these patients can be considered as decompensation of the primary dysfunction of the placenta with the transition to acute placental insufficiency.The formation of chronic placental dysfunction, clinically manifested by the syndrome of fetal growth retardation, was most often observed in patients whose pregnancy ended in spontaneous premature birth at 34–36+6 weeks in the presence of an untouched amnion, – 68.6% compared to births at 28–33+6 weeks of gestation – 25.9% and with childbirth at 22–37+6 weeks – 13.3%.Conclusions. Clinical manifestations of placental dysfunction were detected in 30.6% of patients with premature birth, with morphological signs in 60.4% of cases, which indicates the hidden course of placental insufficiency before the development of premature birth.Morphological signs of placental dysfunction were determined in 87.5% of cases of premature births for medical reasons and in 100.0% of cases of spontaneous births at 22–27+6 weeks of gestation (with a combination of risk factors from 2.1 to 3.0), in 66.7% – with premature births at 28–33+6 weeks of pregnancy, in 40.0% – with premature births at 34–36+6 weeks of pregnancy and only in one (5.6%) case – with term births.The frequency of fixation of morphological characteristics of placental dysfunction correlates with the frequency of early pregnancy complications, primarily with the formation of retrochorial hematomas in the first half of pregnancy.