A Retrospective Study Of Fetal Single Umbilical Artery With Cardiovascular Malformation And Its Pregnancy Outcome

Objectives:By analyzing the results of prenatal systematic ultrasound screening of single umbilical artery（SUA）fetus in single pregnancy and the related clinical data,to investigate the relationship between SUA and cardiovascular malformation and its effect on pregnancy outcome,so as to provide a basis for the pregnancy selection and management of SUA pregnant women in clinical practice.Methods:A retrospective analysis was performed on the ultrasound imagings and clinical data of 130 fetuses with single pregnancy diagnosed as SUA by systematic ultrasound screening in Medical Ultrasound Department of our hospital on January 1,2006 to October 31,2019.All SUA were confirmed by the general specimen or pathology of umbilical cord after delivery.According to prenatal ultrasound examination,whether there is congenital malformation,the fetus with SUA was divided into isolated single umbilical artery（iSUA）and non-isolated single umbilical artery（niSUA）.According to the absence of the umbilical artery（AUA）,they were divided into the left AUA group and the right AUA group.60 iSUA fetuses with complete clinical data were included in the i SUA group and60 normal fetuses were included in the control group.Using GE Voluson 730 and GE Voluson E8 color doppler ultrasound diagnostic instrument,according to the prenatal ultrasound examination guidelines（trial）and prenatal ultrasound examination guidelines（2012）,the routine measurement of fetal biological indicators to estimate fetal gestational weeks,the system orderly to the fetal structure and appendage for a detailed scan to determine whether there is SUA and other structural abnormalities.Fetal echocardiography was performed when SUA was found.SUA was diagnosed according to the“Lv”shape of the free amniotic fluid section of the umbilical cord and the blood flow signal of one side of the umbilical artery on the cross-section of the bladder,and the AUA was determined according to the fetal position.Postpartum autopsy was performed on those with severe malformation induced labor.For those who continued pregnancy with i SUA and minor deformity of SUA,color doppler ultrasound was performed regularly during pregnancy,and the birth status of the newborn was followed up.Results:1.Among the 130 SUA cases,91 were iSUA（70%）and 39 were ni SUA（30%）.SUA combined malformation occurred in each fetal organ system,among which 30 cases（23.1%）of cardiovascular system,10 cases（7.7%）of genitourinary system,10 cases（7.7%）of skeletal system and 10cases（7.7%）of face were more common.The incidence of multiple malformations in SUA was 1.6 times that of single malformations.2.Among the 30 cases of SUA fetuses with cardiovascular malformations,10（33.3%）had single cardiovascular malformations and20（66.7%）had other system malformations.22 cases（73.3%）were complex cardiovascular malformations,and 8 cases（26.7%）were simple cardiovascular malformations.25 cases（83.3%）of labor induction and 5cases（16.7%）of live labor were followed up with postpartum ultrasound.The top three cardiovascular malformations were ventricular septal defect（17/30,56.7%）,persistent left superior vena cava（6/30,20%）and persistent arterial trunk（5/30,16.7%）.3.There were 82 cases（63.1%）in the left AUA group and 48cases（36.9%）in the right AUA group.The left AUA was 1.7 times that in the right AUA,and the incidence of left AUA combined with multiple malformations and complex cardiovascular malformations was significantly higher than that of the right AUA group,and the difference was statistically significant（24.4%vs 8.3%,P=0.023;23.2%vs 6.3%,P=0.013）.4.The incidence of cesarean section in the iSUA group（35/60,58.3%）was significantly higher than that in the control group（14/60,23.3%）,and there was marked difference between them（P<0.001）.There was no significant difference in the incidence of cesarean section due to fetal factors,premature rupture of membranes,fetal distress,stillbirth,preterm delivery,intrauterine growth retardation and small for gestational age（P>0.05）.5.The birth weight of the newborn in the iSUA group（2973.33±534.04g）was significantly lower than that in the control group（3318.17±374.64g）,and there was marked difference between them（P<0.001）.There was no significant difference between the two groups in gestational age at birth,Apgar score of 1 minute and 5 minutes,and the incidence of admission to NICU after birth（P>0.05）.6.PaCO₂ of umbilical artery in iSUA group（57.17±10.08mmHg）was significantly higher than that in control group（52.67±10.15mmHg）,and there was marked difference between them（P=0.016）;there was no significant difference in PH,PO₂,BE between the two groups（P>0.05）.Conclusions:1.Single umbilical artery combined with malformation can occur in every organ system of fetus,and cardiovascular malformation is the most common,and most of them are complex cardiovascular malformations,with poor prognosis.2.In the single umbilical artery fetus,the left AUA is more common,and it is more likely to be associated with multiple malformations and complex cardiovascular malformations.3.The isolated single umbilical artery has a certain influence on the growth and development of the fetus,and the fetus has a lower birth weight.4.The isolated single umbilical artery has certain influence on fetal circulation,and some fetus are in mild hypoxia state.