Occasionally, there is only the one<unk>  <unk>  present in the<unk>  cord. This is sometimes also called a two-vessel<unk>  cord, or two-vessel cord. Approximately, this affects between 1 in 100 and 1 in 500 pregnancies, making it the most common<unk>  abnormality. Its cause is not known. Most cords have one vein and two<unk> es. The vein carries oxygenated blood from the placenta to the baby and the<unk> es carry deoxygenated blood from the baby to the placenta. In approximately 1% of pregnancies there are only two vessels —usually a<unk>  vein and<unk><unk> . In about 75% of those cases, the baby is entirely normal and healthy. One<unk>  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. Doctors and midwives often suggest parents take the added precaution of having regular growth scans near term to rule out intrauterine growth restriction, which can happen on occasion and warrant intervention. Yet the majority of growth restricted infants with the abnormality also have other defects. Finally, neonates with the finding may also have a higher occurrence of renal problems, therefore close examination of the infant may be warranted shortly after birth. Among<unk>  infants, there is a slightly elevated risk for post-natal urinary infections.
Single umbilical artery
Cervical agenesis
Persistent cloaca
Fetal aortic stenosis
Omphalocele
Vaginal atresia
Iniencephaly
Craniopagus twins