The Umbilical Cord I
A frequent question of the woman during her pregnancy is: Can my baby get tangle up with the umbilical cord? What happens if it gets tangled around my baby’s neck? How can I know if during labor it isn’t going to tighten even more and suffocate my baby?
The umbilical cord is a fundamental structure of mammals. It is through it that the fetus is going to receive all the nutrients in the form of the glucose molecule, the air that the mother breaths in the form of the oxygen molecule and an innumerous of indispensable components for its intrauterine life. Throughout the umbilical cord, it passes from the fetus to the mother all of the fundamental waste products from the respiration and the fetal metabolism.
The cord varies in length and in diameter sometimes being very long or very short, thick or very thin. It’s elastic and very resistant. The baby’s play around during their intrauterine life with the umbilical cord and I even dare to say that it is the baby’s first toy! This is well seen in the ultrasounds when we see them tighten it and loosen it frequently.
When the cord tightens or compresses the fetus receives less blood. Immediately he feels a sensation of suffocation because it’s receiving a lot less oxygen. It’s like if someone covers the mouth and the nose of a child all the sudden. What does the fetus do then? He releases immediately so that he can get out of the urgency and receive again the air that the mother is sending, which is the oxygen that goes throughout the umbilical cord.
Sometimes the fetus tightens the cord with an extremity or with their own body. What do they do then? They move and change position. It is frequent that the future mother tells us about “abrupt movements” of his daughter or son that sometimes wakes her up during the night. It is more of the same: the baby waking up the mother so that she changes position and he can get out of the hurry.
Said in other words, the compression of the umbilical cord during the fetal life it’s a magnificent respiratory exercise that trains the future infant to deal with critical situations when a lack of air exists. This ability accompanies the human being during its lifetime. These intrauterine compressions occur as many times as the occasions when the fetus sucks on his thumb. It occurs frequently and during the whole pregnancy.
How can we know if during labor there is a dangerous compression of the cord?
Actually it isn’t difficult or complicated. It’s listening and auscultating the fetus heart frequently during the labor.
When the cord compresses is makes a drop of the Fetal Cardiac Frequency. Meaning that if the heart of the fetus was beating for example at 130-140 beats per minute it produces a descent or a drop in the Fetal Cardiac Frequency of 70-80 beats per minute. This drop is sudden and brief and it goes away quickly.
What happens after the drop or descent of the FCF?
Immediately after the compression of the cord meaning after the drop of the FCF, a compensatory tachycardia occurs. To make it even clearer during the minutes after the drop, the fetus heart accelerates leading the hearts frequency to 170-180 beats per minute. Then it goes back to its usual rate of 130-140 beats per minute. This way the fetus receives the oxygen that he stopped receiving during the compression. It’s what a child does for example, after holding its breath when he submerges in a pool. When he gets out, he takes a deep breath several times.
We can listen to the cardiac frequency in several ways:
Putting an ear on the mother’s abdomen, auscultating with the stethoscope or a Pinard horn or with a Doppler or a Fetal Monitor.
The auscultation mustn’t be continuous or permanent. It is very uncomfortable for the mother and it doesn’t have any advantage. The auscultation or monitoring of the Fetal Cardiac Frequency it’s intermittent. It’s performed frequently during the labor job in brief periods trying to make the mother the least uncomfortable.
Next time we will make an explanation in relation to the enormous benefits that the water birth has when an umbilical cord compression happens in the moment of childbirth.
To conclude I must add that the odds of the umbilical cord around the neck can be present in 30-40% of all childbirths around the world, so it is an usual and normal event during any birth. The real accident of the cord, meaning a real tighten nod of the cord or a real and mortal compression of the cord, it is produced in a rate of 1 to 40.000 childbirths!! In other words it is extremely rare. In Panama there are born 50.000 infants per year which means that the real cord accident happens once a year.
Dr. Rodrigo Aybar
Dra. Graciela A. devAybar