Oxygen and nutrients from the mother's blood are transferred across the placenta to the fetus through the umbilical cord. There it moves through a shunt called the ductus venosus. This allows some of the blood to go to the liver. But most of this highly oxygenated blood flows to a large vessel called the inferior vena cava and then into the right atrium of the heart. When oxygenated blood from the mother enters the right side of the heart, it flows into the upper chamber the right atrium.
Most of the blood flows across to the left atrium through a shunt called the foramen ovale. From the left atrium, blood moves down into the lower chamber of the heart the left ventricle. It's then pumped into the first part of the large artery coming from the heart the ascending aorta. From the aorta, the oxygen-rich blood is sent to the brain and to the heart muscle itself. While a SUA can be easily detected by the presence of only one umbilical artery lateral to the fetal bladder, the presence of supernumerary umbilical veins tends to be overlooked, as it is often difficult to check the number of umbilical veins throughout the length of the umbilical cord.
We consider that it is important to evaluate the number of umbilical cord vessels in the second trimester using ultrasound combined with color Doppler in at least three sites: the insertion sites on both the fetal abdomen and placenta, and at more than one point in the free loop of the umbilical cord. The number of umbilical cord vessels must be examined because abnormalities may suggest the presence of congenital anomalies. Single umbilical artery and its associated findings.
Obstet Gynecol. Article Google Scholar. An accessory fourth vessel of the umbilical cord. A preliminary study. Am J Obstet Gynecol. Painter D, Russell P. Four-vessel umbilical cord associated with multiple congenital anomalies. Four-vessel umbilical cord: not always a dire prognosis. J Ultrasound Med. Practice guidelines for performance of the routine mid-trimester fetal ultrasound scan.
Ultrasound Obstet Gynecol. Sadler TW. Google Scholar. The human fetal venous system: normal embryologic, anatomic, and physiologic characteristics and developmental abnormalities.
Persistent intrahepatic right umbilical vein in the fetus: a benign anatomic variant. Jeanty P. Persistent right umbilical vein: an ominous prenatal finding? Supernumerary umbilical vein resulting in a four-vessel umbilical cord. Am J Perinatol. Four-vessel umbilical cord. Neonatal outcomes in fetuses with a persistent intrahepatic right umbilical vein.
Murdoch DE. Umbilical-cord doubling. Report of a case. Prenatal diagnosis of four-vessel umbilical cord with supernumerary vein varix: a case report and literature review. J Obstet Gynaecol Res. Download references. Maria Clinic for supporting this report. You can also search for this author in PubMed Google Scholar. Both MKs and MM analyzed the case and wrote the manuscript.
TM and EO performed neonatal physical and ultrasound examinations. YT and MH performed the histological examination of the umbilical cord. All authors critically reviewed and revised the manuscript. All authors read and approved the final manuscript.
Correspondence to Fusanori Yotsumoto. Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Doctors aren't sure what causes it. The cord forms early as the baby develops.
In most cases, a single artery is found with an ultrasound. The test is done in the second trimester. It uses sound waves to make pictures of the baby fetus inside the uterus.
It helps your doctor or midwife look for problems with the heart, kidneys, or other areas. If the test shows a single artery, your doctor may do more tests while you are pregnant. For instance, you may have detailed ultrasound tests to see if there are any other problems. A scan may be done in the third trimester to see how your baby is growing. There is no treatment for a single umbilical artery. Your doctor or midwife will watch how your baby develops before and after birth.
If other problems are found, your doctor or midwife will talk to you about treatment. Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse call line if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.
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