Features of echographic and Doppler indicators in spontaneous pregnancy for monochorionic biamniotic twins
Authors: Tkachenko A. V. 
Published: July 2021

Purpose of the study: determination and analysis of echographic and Doppler indicators during pregnancy with monochorionic biamniotic twins.Materials and methods. The study involved 198 pregnant women aged 18–38 years, who were divided into three clinical groups. The I (control) clinical group included 65 (32.8%) pregnant women with uncomplicated singleton pregnancy (OB); the II clinical group included 60 (30.3%) patients with bichorionic biamniotic twins (BHBA); Clinical group III included 73 (36.9%) women with pregnancy with monochorionic biamniotic twins (MCBA). In order to elucidate the differential diagnostic criteria and more detailed assessment of the pathogenetic factors of the development of twin overflow syndrome (SBP) in the III clinical group, two subgroups were identified: III-A subgroup, which included 21 (28.8%) pregnant women with MCBA with twins and signs SBP, and III-B subgroup, which included 52 (71.2%) pregnant women with MCBA twins and no signs of SBP.Results. The diagnosis of MCBA of twins was established by ultrasound examination at 6–8 weeks of gestation in 56 (76.7%) patients, after 8 weeks - in 17 (23.3%) patients. A complex of pathological manifestations detected during an ultrasound scan (a combination of polyhydramnios in one of the fetuses with oligohydramnios in the other, discordant fetal development (DRP) of more than 20%, no visualization of the bladder in the recipient fetus and / or the presence of a large bladder in the fetus - donor, a decrease in motor activity in a smaller fetus, characteristic changes in Doppler measurements in the fetal-placental and fetal vessels, signs of anemia in a smaller fetus, etc.), made it possible to diagnose SBP antenatally in 21 (28.8%) patients from the III clinical group, among them, 11 (52.4%) were diagnosed with stage I SBP (according to the classification of R. Quintero et al.), 8 (38.1%) - stage II SBP.In 2 (9.5%) patients in the II trimester of pregnancy, severe forms of rapidly progressing SBP with signs of a growing sequence of low and polyhydramnios, progressive deterioration of Doppler parameters in the umbilical cord arteries of both fetuses, with an increase in the peak blood flow velocity in the middle cerebral artery of donor fetuses were revealed. ascites in recipient fetuses. In these pregnant women, an attempt was made to perform laser coagulation of vascular anastomoses in the placenta under ultrasound navigation control at 16 (+5) and 18 (+3) weeks of gestation. However, pregnancy ended in premature birth at 24 (2) and 25 (+4) weeks and was accompanied by intrauterine death of one smaller fetus (in 1 case) and early neonatal death of a large fetus (in another case).With MCBA twins not burdened with SBP, the mean values ​​of anthropometric parameters of both fetuses did not differ significantly. At the same time, in the presence of SBP, the biometric indicators of the donor fetus were probably lower relative to fetus A (this same subgroup), and when compared with similar anatomical indicators of fetuses in pregnant women of III-B subgroup. This clearly confirms the likelihood of the effect of progressive SBP on fetal growth rates and an increased risk of IGR and chronic distress (especially in donor fetuses).Conclusion. Complex ultrasound and Doppler assessment of uteroplacental-fetal blood flow in multiple pregnancies is an objective tool that allows to establish prognostic and diagnostic criteria for the development of obstetric complications, fetal disorders and perinatal outcomes. Prognostically unfavorable for the development of obstetric and perinatal complications associated with the formation of IGR and DRP in MCBA twins are early detection of a decrease in the diastolic component of blood flow, a significant increase in ADV, PI and IR in the umbilical cord arteries and aorta of fetuses in the dynamics of the II and III trimesters (p<0 ,05).The combination of an increase in peripheral vascular resistance with the centralization of blood circulation is manifested by violations of hemodynamic parameters in the middle cerebral artery of the fetus, which is typical in the case of the development of SBP in fetuses with MCBA of twins.