The following is a letter that I wrote to a client after her two births both resulted in emergency cesareans for fetal distress. Both babies were determined to have long umbilical cords that possibly led to the fetal distress as they were pinched between the baby and the mother’s pelvis. She was concerned that the same would happen to baby number 3 and asked if there was any information about a connection between the two. This is what I found:
“In light of our conversation about your next birth, I did some research on long umbilical cords. Before you get all this planted in your brain, you should find out for sure how long Isaac and Levi’s cords were. You should be able to find out by contacting Cathy Heffernan, since she should have records from both births.“The length of the umbilical cord varies from no cord (achordia) to 300 cm, with diameters up to 3 cm. Umbilical cords are helical in nature, with as many as 380 helices. An average umbilical cord is 55 cm long, with a diameter of 1-2 cm and 11 helices.1 For unknown reasons, most cords coil to the left.2 About 5% of cords are shorter than 35 cm, and another 5% are longer than 80 cm.3
Causes of differences in cord length are unknown, however the length of the cord is thought to reflect movement of the fetus in utero. Short cords are associated with fetal movement disorders and intrauterine constraint, as well as placental abruption and cord rupture. Excessively long cords are associated with fetal entanglement, true knots, and thrombi.”
First pregnancies tend to generate shorter cords than subsequent pregnancies. Other known associations with long cords are maternal systemic diseases, delivery complications, increased maternal age, non-reassuring fetal status during labor, respiratory distress of the fetus, vertex presentation, cord entanglement, fetal anomalies, male sex of the fetus, increased birth weight, increased placental weight, right-twisted cords, hyper-coiled cords, and true knots in cords. These associations may either put a woman at increased risk for, or may be a result of, excessively long umbilical cords (ELUC).
Having an ELUC does not guarantee having problems as a result (such as knots or compression resulting in fetal distress during labor). Long cords still function normally, being able to pump blood back and forth, just like an average length of cord. Even knots in the cord do not automatically cause distress, since blood flow is not impeded unless the knot is tight. Risk factors for having a true knot(s) in the umbilical cord include: Advanced maternal age, multiparity, previous miscarriages, obesity, prolonged gravidity, male fetus, long cord, maternal anemia, maternal chronic hypertension, and hydramnios. Occasionally, a bunch of cord loops may create a false impression of a cord knot on the ultrasound screen, so an ultrasound should not be used as the sole test of health of the baby.
As to a connection between you developing longer cords with each baby, “Although no published report of a genetic relationship exists, there may be one”. This means that if a woman has a short or long cord with her first baby, she may be more likely to have the same with subsequent pregnancies, but because of lack of evidence, this possibility is not guaranteed and you should not base your decision making around that possibility.
You also mentioned the scary idea of the problems associated with their births causing a stillbirth. Reassuringly, I found that studies affirm stillbirth likely only rarely a direct result of excessively long or excessively short umbilical cords.
As to prevention of difficulties, and detection of a long cord, it is very difficult to assess the length by ultrasound. However, it is possible to make sure that there are no tight knots, by assessing the rate of blood flow through the cord, by a technique known as “Pulsed wave Doppler spectral analysis”, I believe this is performed by an ultrasound scanning.
Impaired circulation in the mother, especially while asleep, has been known to impair blood flow to the fetus, causing distress. To counter this, a baby will grow especially active to stimulate maternal activity and therefore uterine blood flow. This unusual activity by the baby can result in cord compression and or entanglement. If this continues, especially in combination with Braxton Hicks or prolonged contractions, the baby may become stressed. In this situation, if you noticed hyperactivity, especially at night, make an effort to get up and walk to the bathroom to stimulate blood flow. Mention it to your caregiver, who may then perform a NST. An ultrasound can be done to look for cord compression or damage to the cord.
Take what you will from this and toss the rest, please do your own research as well. I cannot give you advice because I am not your caregiver, but I will tell you what I think I would do in your situation. During my pregnancy I would do a lot of visualizing of the cord being of normal length, working fine and being in a good position. I would pray for God’s blessing, and except His peace. I would also seek multiple people to continually pray for me through my pregnancy and birth. I would find positive birth stories involving long cords. I would try to avoid things that would stimulate hyperactivity in my baby, like caffeine. I would plan a homebirth, but find a supportive backup doctor/midwife at the hospital. Towards the end of my pregnancy, I would get an ultrasound, to get as much information about the health of my umbilical cord, and I would also try to get small amounts of regular exercise to help blood flow. Then, knowing I had done everything I could, I would focus on preparing myself for birth, and try to enjoy the rest of my pregnancy.
I encourage you to do your own research, for starters, here are a few of the websites where I found the above information:
http://www.emedicine.com/med/topic3276.htm#section~CordLength
