I am researching the effects of knotted cord and its possible causation or correlation with causing infant-death. With online research I am finding that 1%-2% of babies are born with a true knot, however how many of this 1%-2% cause stillbirth? In addition, what variables lead to the formation of a true knot? Can it be prevented?
The number seems to be somewhere between 4 and 10 times larger as with no umbilical cord knot present.
In a study of 70000 births, umbilical cord knots occurred in 1.2 percent of births. The fetal death rate in these births was four times higher than for the control group without knots, at 1.9 percent of births.
In another study, on 20000 births, a 10 times increased risk of intrauterine death was found.
In yet another study, for around 27000 births, an eight fold increase in fetal death was found. True umbilical cord knot and obstetric outcome
Umbilical cord knots can sometimes be determined by ultrasound before delivery. If a cord knot is found, a C-section is performed.
According to the first study, risk factors appear to be
gestational diabetes, hydramnios, patients undergoing genetic amniocentesis, male fetuses