History:

A 23-year-old primigravida had received routine prenatal care throughout her pregnancy and had problems only with mild hyperemesis gravidarum. The size of the fetus by examination was consistent with 38 weeks gestational age on her last prenatal visit. However, a week later she called her physician because she had not felt any fetal movement for a whole day. An ultrasound performed at the physician's office revealed no cardiac activity. A stillborn baby was delivered soon thereafter. The placenta weighed 550 gm and had an 82 cm long umbilical cord with three vessels that inserted paracentrally.

Image 2.1:

What is wrong with this appearance of the umbilical cord?

There is a true knot of the cord.

Image 2.2:

Here is another umbilical cord from a placenta in which the baby was liveborn. What would you call this?

This is a pseudoknot of the cord, which is just an exaggeration of one umbilical vessel.

Image 2.3:

A fetus is shown here. What is the abnormality?

There is a loop of cord around the neck of the baby, a nuchal cord.

Questions:

1. What is the significance of umbilical cord length?

Longer cords may predispose to cord accidents such as knots or nuchal cord.

2. What determines the length of the cord?

Fetal movement plays a role in cord length. A fetus that has greater movement tends to have a longer cord. A fetus with restricted movement (oligohydramnios) or neurologic defects tends to move less and have a shorter cord.

3. What is the significance of the nuchal cord?

It may have no significance at all, or it may represent the possibility of a situation leading to fetal hypoxia. A nuchal cord is more likely with an abnormally long umbilical cord (>70 cm).