Pregnancy is an exciting journey filled with many developmental milestones for the growing fetus and the mother. But sometimes, unexpected findings during prenatal screenings can make the parents anxious. In this blog, you will learn about one common condition called the Single Umbilical artery (SUA) and its significance on the baby and the mother during pregnancy.
Veins and arteries are integral parts of the circulatory system. A vein is a blood vessel that gathers oxygen-poor blood and sends it back to the heart. On the other hand, arteries are blood vessels that help transfer blood rich in oxygen from the heart to other body parts.
Typically, an umbilical cord has one vein and two arteries. But sometimes, a pregnant woman has one artery instead of two, and this condition is called a single umbilical artery or two-vessel umbilical cord. It is reported in 0.5 to 6% of single pregnancies, and the risk increases three to four times in multiple pregnancies.
There are three types of single umbilical artery:
An abnormality of Type 2 can decrease blood flow and nutrient supply to the fetus. In the case of Type 3, the fetus may have problems with blood circulation. Hence, it is essential to perform a prenatal ultrasound during the second and third trimesters so that any anomalies, such as a single umbilical artery, can be determined and the health of the mother and the fetus monitored.
Babies with this condition are at a slightly higher risk of congenital problems. The most common abnormalities include renal, cardiovascular, and musculoskeletal. The renal malformation leads to Vesicoureteral reflux, where the urine flows backwards into the uterus or sometimes to the kidneys. So, urinary tract infections may need to be managed in babies.
Newborns with a single umbilical artery have a 15 times higher likelihood of chromosomal abnormalities. There is also a risk of placental anomalies and a higher chance of hydraminos. Plus, the condition increases the chances of
The exact cause of the single umbilical artery is unknown, but several factors can contribute to this condition:
A single umbilical artery can be present in pregnancies and does not cause any of the above-mentioned risks. So, it is essential to have regular antenatal checks, including ultrasounds for fetal malformations screenings.
A sonographer who performs the ultrasound will first determine if the baby has any conditions involving a single umbilical artery condition and perform the routine scan during the first trimester. Then, in the second trimester, an anomaly scan is performed to check if the baby has a single umbilical artery. If there is this condition, there will be no problems in most cases, and the scan does not show any issues. It is called an isolated single umbilical artery, and the outcome is usually a healthy baby. However, if you are having multiple pregnancies, you will need further scans in your third trimester. Multiple pregnancies grow at a slower pace in SUA, so it is essential to get a regular check on whether one is growing slowly compared to the other. In a few cases, congenital disabilities may be found along with SUA. The parts affected are the central nervous system, kidneys, gut and heart. The sonographer will check them as part of the anomaly scan. If any such defects are found, you may be offered more tests like amniocentesis to check for Trisomy 18 and other genetic conditions.
In most cases, an SUA does not have an impact on the baby's delivery. However, suppose there are additional abnormalities or complications, like congenital anomalies, fetal growth restriction, etc. In that case, your doctor may recommend an individualised birth plan which includes C-Section delivery to minimise risk. Following the baby's birth, additional monitoring and follow-up care are needed to ensure the baby is grows healthily. This may include diagnostic testing, paediatric evaluations, and ongoing treatment to manage any complications.To conclude, if you are screened for a single umbilical artery during pregnancy, there can be some anxious moments for the soon-to-be parents. There is no treatment for a single umbilical artery, only management. However, it is essential to note that many pregnancies with SUA have positive outcomes, with the child born healthy. However, it is essential to keep a close eye on fetal development during pregnancy by getting regular prenatal checkups so that you and the baby have the best outcome. There may be associated risks and complications, but advances in screening and diagnostics help manage them effectively. Understand the causes, risks and significances of SUA to make informed decisions and go through pregnancy with confidence.
The most common cause of a single umbilical artery is the failure to develop an umbilical artery during early pregnancy.
Yes. If the baby exists, most babies with a single umbilical artery have a good prognosis and grow and develop into healthy babies.
