The umbilical cord of a fetus is an amazing organ that provides important information regarding fetal well-being. A cord that is too long can either develop a knot or end up wrapped around the baby’s neck. A cord that is too short can cause the placenta to separate too soon causing what’s known as a placenta abruption.

The umbilical cord is supposed to have two arteries and one vein but this is not always the case. In less than one percent of cases there is only one artery rather than two, a condition that’s commonly called a 2-vessel cord or a single-umbilical-artery.

A 2-vessel cord occurs more frequently in small babies, preemies and twins. It also occurs more frequently in babies with genetic disorders and birth defects. Thanks to improved images from ultrasounds, many of these defects can be detected before the fetus is born. If an ultrasound report identifies a 2-vessel cord, everyone should be on alert. Such was the case of my patient, Madeline*.

Madeline was a working mother of three who had late prenatal care. She had a stressful job and couldn’t get time off from work to make an earlier appointment. Her first appointment was in the third trimester. When her ultrasound report documented a 2-vessel cord , my antennas immediately went up. I referred her for a specialized ultrasound who documented that the estimated weight of her baby was on the lower side of normal. I decided to watch her closely with weekly exams and non-stress tests. She also took an early maternity leave. During her 37th week, she developed contractions and had a 4th c. section. Although her baby weighed 4 pounds, it was healthy , continues to grow and there are no obvious birth defects.

Statistics state that 70 to 80% of babies with 2-vessel cords will not have complications, but in the world of obstetrics it is better to be safe than sorry. All pregnant women should know the number of blood vessels of their babies’ umbilical cords. If a 2-vessel cord, please insist on a specialized ultrasound (aka target) and a consultation with a maternal-fetal-medicine specialist who will follow the weight of your unborn child.

 “The risks of pregnancy and childbirth are often under appreciated.” A healthy pregnancy doesn’t just happen. It takes a smart mother who knows what to do.

*Name changed