My daughter had a single umbilical artery. We found this out at the big 20 week ultrasound when the perinatologist oh so casually mentioned it. I was scared. I wouldn't google this. You'll find a load of stuff that will make you stay up at night. I scared myself silly and spent the next half of the pregnancy worried about the baby. It's no wonder my bp went up in the third trimester. Our peri told us that he believed our daughter had the two typical umbilical arteries but early in the pregnancy one disintergrated for whatever reason. The remaining artery grew larger to compensate. It's just one of those things that happen. There are many of us walking around who probably had SUAs but we don't know since back in the day there weren't these super duper ultrasounds. An SUA would have been discovered when the doctor cut the cord.
A SUA is in and of itself not an anomaly but it can lead to anomalies in a small percentage of babies. I think something like 70% of babies with an SUA are perfectly normal and healthy.
The rest may have kidney or heart issues but if the ultrasound shows the kidneys and heart are fine, I wouldn't worry. My daughter's ultrasound showed her kidneys and heart were fine. If I'm not mistaken the heart and kidneys are affected because the same tissue that forms the heart and kidneys have something to do with the umbilical artery. Someone correct me if I'm wrong.
I had to do a couple of NSTs in the last few weeks of my pregnancy but that had more to do with my mild pre-eclampsia than the SUA. My ob wasn't concerned about the SUA at all. There wasn't any talk of induction or a section because of the SUA. I ended up having both but for reasons wholly unconnected with my daughter's umbilical cord.
And my daughter is perfectly fine.