Single umbilical artery
Single umbilical artery | |
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Cross-section of an umbilical cord with a single artery | |
Specialty | Obstetrics, maternal–fetal medicine |
Occasionally, there is a single umbilical artery (SUA) (Vasa praevia) present in the umbilical cord, as opposed to the usual two.[1] This is sometimes also called a two-vessel umbilical cord, or two-vessel cord. Approximately, this affects between 1 in 100 and 1 in 500 pregnancies, making it the most common umbilical abnormality. Its cause is not known.
Most cords have one vein and two arteries. The vein carries oxygenated blood from the placenta to the baby and the arteries carry deoxygenated blood from the baby to the placenta. In approximately 1% of pregnancies there are only two vessels —usually a single vein and single artery. In about 75% of those cases, the baby is entirely normal and healthy. One artery can support a pregnancy and does not necessarily indicate problems. For the other 25%, a 2-vessel cord is a sign that the baby has other abnormalities—sometimes life-threatening and sometimes not.[2]
Doctors and
Presentation
Associations
SUA does increase the risk of the baby having cardiac, skeletal, intestinal or renal problems.
It may be associated with Trisomy 18, also known as
Diagnosis
It can be detected in the first trimester of pregnancy with the use of 2D ultrasound. The sonographer is able to identify a 2 vessel cord in an image with the bladder and color Doppler, which will show only one artery going around one side of the bladder. In a normal fetus, there would be 2 arteries (one on each side of the bladder).
Prognosis
Although the presence of an SUA is a risk factor for additional complications, most fetuses with the condition will not experience other problems, either in utero or after birth. Especially encouraging are cases in which no other soft markers for congenital abnormalities are visible via ultrasound. Given that, the vast majority of expectant mothers do not receive the kind of advanced ultrasound scanning required to confirm SUA in utero.[citation needed]
Epidemiology
It is slightly more common in multiple births, in infants with chromosome anomalies, and in girls than in boys.[6][7]
See also
References
- S2CID 21520002.
- ^ "Could Your Umbilical Cord or Placenta Cause You Trouble?". Archived from the original on 2013-10-04.
- ^ "Pregnancy". 8 December 2020.
- PMID 23088440.
- PMID 25101287.
- PMID 2000332.
- PMID 6514541.