Features of the course of pregnancy with a single umbilical artery of the fetus

Among the abnormalities in the number of umbilical cord vessels, the single umbilical artery (SUA) is most common. The influence of some endocrine, gynecological and general factors on the occurrence of SUA, the detection of SUA at different stages of pregnancy, as well as the effect of SUA on the course of pregnancy and the condition of the fetus are assumed. In most cases, according to different data – 57–75%, SUA is an isolated change and does not affect the course of pregnancy and childbirth, as well as the postnatal period. Other authors see a significant impact of SUA on the course of such pregnancy and childbirth. The article presents some features of the course of pregnancy with SUA compared with pregnant women with three umbilical cord vessels and physiological labor in the future. The objective: to study and analyze the peculiarities of pregnancy with SUA, to conduct a comparative description of the revealed features with such indicators among pregnant women with three umbilical cord vessels. Materials and methods. 31 pregnant with a single umbilical artery of the fetus (study group), 62 pregnant with 2 umbilical arteries of the fetus (control group). Results. In pregnant women with SUA, increased body weight, first blood group, and diseases of insulin-dependent diabetes mellitus were observed with greater frequency. In the history of pregnant women with SUA, artifactual abortions, spontaneous miscarriages, or missed pregnancies are more common than pregnant women who have two umbilical arteries of the fetus. Among pregnant women with SUA during pregnancy, the risk of miscarriage, fetal growth retardation, placental dysfunction, polyhydramnios, gestational diabetes and the threat of premature birth are significantly more common. Premature birth occurs in 12.9% of pregnant women with SUA. The reverse blood flow in the venous duct, detected by ultrasound at 12–13 weeks of gestation, was detected in 19.4% of pregnant women with EPA. According to Doppler, when comparing pregnant women with fetal EPA and two umbilical arteries, there are true negative changes in the direction of increased peripheral vascular resistance (according to the blood flow velocity in the aorta of the fetus) and a tendency to centralize blood circulation (according to cerebro-aortic index) in fetuses with SUA. The average Doppler indices of other vessels of the placental complex do not differ between the two studied groups of pregnant women. According to hormonal studies in pregnant women with SUA at the end of the first trimester of pregnancy in 26.8%, rates of PAPP-A were higher than the reference values (in the control group – 6.4%). Conclusions. Identified features among pregnant women with SUA, such as increased body weight, first blood group, diseases of insulin-dependent diabetes mellitus and a significant number of spontaneous miscarriages and missed abortion in history, can be cumulative risk factors for the occurrence of SUA. Among pregnant women with SUA during pregnancy, the threat of miscarriage, fetal growth retardation, placental dysfunction, polyhydramnios, gestational diabetes and the threat of premature birth are significantly more common. Premature birth occurs in 12.9% of pregnant women with EPA. In the period of 12-13 weeks, the reverse blood flow in the venous duct can be considered a marker of SUA. The features we found in terms of Doppler metrics indicate true negative changes in the direction of increasing peripheral vascular resistance (according to the blood flow velocity in the aorta of the fetus) in fetuses with SUA. An increase in PAPP-A can serve as a marker of the presence of SUA in the fetus in early pregnancy. Key words: single umbilical artery, fetal growth retardation, placental dysfunction, polyhydramnios, gestational diabetes, venous duct, dopplerometry, PAPP-A.