A new study shows that children born with only one artery in their umbilical cord have a slightly increased risk of certain developmental disorders later in life. However, for the vast majority of children, this does not appear to affect development.
The umbilical cord is the fetus's lifeline. It connects the placenta and the fetus, transporting all the gases and nutrients needed for the fetus to develop.
In most people, the umbilical cord consists of two arteries and one vein. A small number – around 0.4% of all newborns – are born with only one umbilical artery. This is called isolated single umbilical artery (iSUA). The condition is known to be associated with complications during pregnancy, but it has been unclear whether iSUA may also be associated with neurodevelopmental disorders later in childhood.
In this large Norwegian study, the largest of its kind, researchers followed over 850,000 children born between 1999 and 2013. Of these, just over 3,500 had iSUA but no other congenital malformations. The researchers investigated whether these children were more likely to develop neurodevelopmental disorders such as autism spectrum disorders, ADHD, epilepsy, hearing or vision difficulties, or intellectual disability.
The results showed that children with iSUA had a slightly increased risk of two diagnoses:
- Intellectual disability
- ADHD
However, the increase in risk was modest, and no increased risk of autism spectrum disorders, epilepsy, or hearing or vision impairment was found. Interestingly, the association between iSUA and developmental disabilities was only seen in girls, not boys.
The researchers also examined whether premature birth or low birth weight could explain the association. These explained less than 10% of the increased risk – so only a small part.
What does this mean?
The study suggests that iSUA itself is not a strong risk factor for neurodevelopmental disorders. Only a slight increase in risk for intellectual disability and ADHD was found, and no increase in risk for the other conditions examined.
This is good news for parents who learn during pregnancy that their fetus has iSUA: for most children, this condition does not appear to have consequences for neurological development.
Link to the study: https://obgyn.onlinelibrary.wiley.com/doi/10.1002/uog.70164