Umbilical cord stricture and overcoiling are common causes of fetal demise

Although umbilical cord stricture and umbilical cord overcoiling have been established as causes of intrauterine fetal demise, relatively few studies addressed this issue, most of them being case reports. We reviewed a total of 268 fetal autopsies during a 3-year period from 1998 to 2001. One hundred thirty nine cases of fetal demise including spontaneous abortion were identified. Nineteen percent (26 of 139) were associated with umbilical cord stricture, overcoiling, or a combination of both. Stricture of the umbilical cord was defined as a decrease in diameter in relation of the remaining umbilical cord; overcoiling as 0.3 coil/cm or greater. Fetal demise most commonly occurred in the second trimester, with a mean gestation age of 21 weeks. The average maternal age was 33 years; 15% had a prior fetal demise. We found that 77% (20 of 26) of these cases had umbilical cord stricture only or with overcoiling, 23% (6 of 26) had umbilical cord overcoiling alone. Localized deficiency of Wharton's jelly and increased collagen were found in all cases with umbilical cord stricture with or without overcoiling. In patients with umbilical cord overcoiling alone, 25% had Wharton's jelly deficiency; half of them had increased collagen deposition in the umbilical cords. The placenta was reviewed for secondary thrombosis of the vessels of the chorionic plate. Thrombosis of the vessels of the chorionic plate was noted in 54% of the patients. Our study suggests that umbilical cord stricture and cord overcoiling may represent two distinct pathological entities commonly causing fetal demise. This observation reinforces the importance of a fetal autopsy with careful examination of the placenta and umbilical cord with documentation of the cord coil index.