The Star Legacy Foundation is frequently contacted by couples that have been told their child was stillborn due to an umbilical cord accident. Yet, many obstetricians will also say that babies are born all the time with a nucal cord (cord around the neck) and dismiss that as a cause of a stillbirth. Cord issues aren’t just limited to nucal cords. Simple compression, cord wraps around other body parts, torsion (twisting to the point of coiling back upon itself like a telephone cord does when twisted too many times), and true knots are also known to cause stillbirth.
Many of the same callers ask us what we know about Dr. Jason Collins and his work involving cord accidents. Dr. Collins, an obstetrician, has dedicated his career to stillbirth research and umbilical cord accidents specifically. The following is a brief summary of a presentation he recently gave at the Stillbirth Summit (October 4-6, 2011 in Minneapolis, MN, USA) which is a very high level overview of his research and conclusions.
The presence of umbilical cord issues have been well documented in published literature since the 1700s. Yet, this remains an area of obstetrics that is greatly understudied and ignored. The umbilical cord, the insertion site, the placenta, and the baby should be evaluated and characterized with every pregnancy. With advancing imaging technology, it is becoming even easier to identify areas of concern on ultrasound as early as 10 weeks of gestation.
Umbilical cord torsion occurs when the number of twists exceeds the ability of the cord to withstand the force generated. The cord compression generated causes fetal hypoxia (lack of oxygen). On placental exam, chorioangiosis (cellular changes) can be identified as a result of ischemia (restriction) due to cord compression. The length of the cord determines the amount of twisting that is harmful. The human umbilical cord will tolerate one twist per 5cm of cord length. Twists exceeding this ratio are associated with torsion and fetal death. The length of the umbilical cord and the number of twists present should be identified and documented at every delivery. Identification of torsion prenatally allows for altered management of the pregnancy with a better chance of a positive outcome.
There are two types of nuchal cords: type A and type B. Type A is a wrap that can possibly be undone with movement or delivery of the baby. Type B is a hitch that is impossible for the baby to release. If a type B loop around the neck, ankle, or other body part is pushed off the body, a true knot is formed.
With umbilical cord issues, the factor that determines the risk is the amount of slack available. For this to be determined, the cord location, cord structure, placenta, placental position, cord length, insertion site, and position of the baby must all be evaluated and considered. Short cords have been associated with an increased risk of neurologic insults and long cords have been associated with an increased risk of fetal death.
Work at the Pregnancy Institute has indicated that hyperactivity, hypoactivity, and hiccups may be clinical indicators of fetal distress. Women presenting with these symptoms should be evaluated for sources of cord compression. Fetal heart rate can provide information on this compression as well. Frequent decelerations, “W” signs, lambda signs, and spikes should be taken as indicators of fetal distress and managed accordingly. The exact amount of time that it takes for fetal chemistry to return to normal after cord compression has not been studied, but we estimate that more than three compressions in ten minutes would create increasing blood chemistry concerns and should be dealt with immediately.
Interviews at the Pregnancy Institute have also revealed that a vast number of fetal deaths occur during maternal sleep between the hours of midnight and 6am. Maternal low blood pressure may play a significant role in this finding as a reduction in blood pressure may alter the fetal response to underlying cord issues. Melatonin is produced during sleep and is known to affect the uterus. During these overnight hours, the melatonin produced stresses the uterus and the baby is challenged. Babies with cord compression may not tolerate this stressor.
Finally, work at the Pregnancy Institute has identified that umbilical cord accidents are not random or rare. Women who have had umbilical cord issues with previous pregnancies, have as much as a ten-fold increased risk of umbilical cord issues in future pregnancies. These women need additional monitoring for these concerns.
Management of umbilical cord issues is possible with proper diagnosis and fetal monitoring.
It is true that not all cord issues lead to stillbirth. However, it is also true that cord issues are a significant risk factor and cause many stillbirths. The evaluation of the umbilical cord and placenta should be included in a new standard of care for obstetrics in the 21st century.
About the author:
Lindsey Wimmer, a Pediatric Nurse Practitioner, is Mom to four children; Garrett who was stillborn in 2004, Grant, Bennett and Austyn. Lindsey and her husband Trent founded the Star Legacy Foundation shortly after Garrett’s birth. At that time they came to realize that the numbers of stillbirths in the US were staggering and that very little was being done to determine the causes or find prevention initiatives. Visit the Star Legacy Foundation to learn more.