During pregnancy, the umbilical cord develops into a flexible tube that functions as a supply line between the fetus and mother. The umbilical cord moves blood back and forth between the fetus and the placenta, which is connected to the mother’s blood supply. The three blood vessels that make up the umbilical cord each perform a function supporting the fetus by supplying nutrients and removing waste.
The umbilical cord starts to develop at about five weeks after conception. The cord continues to grow in length, and coil, until the 28th week of pregnancy. The blood vessels, which include two arteries and a vein, are cushioned by tissues that serve as gelatin-like cushions. The arteries carry waste from the fetus to the placenta, where it crosses over into the mother’s blood for disposal in her kidneys. The vein moves oxygen and other nutrients between the mother and the baby through the placenta.
Some cord problems are discovered during ultrasound examinations before delivery, while others are discovered during or after delivery. Umbilical cords can be too long or too short. Single umbilical artery is an abnormality where the umbilical cord has only one artery for multiple fetuses. This abnormality can cause birth defects. Umbilical cord prolapse occurs when the cord drops into the vagina after the mother’s water has burst and before the fetus moves to the birth canal. Cord prolapse, which often leads to cesarean section delivery, can impede the flow of oxygen to the baby and result in stillbirth.
Percutaneous Umbilical Cord Blood Sampling
Percutaneous umbilical cord blood sampling, or PUBS, is also known as fetal blood sampling, umbilical vein sampling and cordocentesis. The PUBS procedure involves extracting a fetal blood sample from the umbilical cord vein. Doctors analyze the blood sample for signs of abnormalities, such as chromosomal defects, blood disorders and infections. Your doctor might order PUBS if additional information is needed about the health of your fetus. Doctors also use the PUBS procedure to perform fetal blood transfusions or administer medication through the fetal blood supply.
The blood that remains in the placenta and the umbilical cord after delivery and cutting of the cord is called umbilical cord blood, or cord blood. Most cord blood is discarded. However, cord blood contains the stem cells that produce all types of blood cells. Doctors use stem cells to treat more than 70 disorders, including genetic blood and immune system conditions, according to the March of Dimes. Mothers can store cord blood for future use in private cord blood banks or donate the cord blood to public banks. Many state regulate the donation of cord blood and require the provision of information to potential donors.