PRENATAL-DIAGNOSIS OF THE 2-VESSEL CORD - IMPLICATIONS FOR PATIENT COUNSELING AND OBSTETRIC MANAGEMENT

The study was designed to investigate the implications of the sonograp hic diagnosis of the two-vessel umbilical cord for patient counselling and pregnancy management. Retrospective analysis was carried out of p renatal findings and pregnancy outcomes when a two-vessel cord was dia gnosed in utero. Eighty-two fetuses each with a single umbilical arter y were diagnosed by ultrasound. Ten were aneuploid, including nine wit h visible structural defects and one with early onset intrauterine gro wth retardation. Of the remaining 72, 31 had other anomalies diagnosed postnatally; 27 of these had structural defects detected on ultrasoun d examination. However, in nine of these 27 sonographically abnormal f etuses, one or more major structural defects were missed by ultrasound examination. Among the 45 chromosomally normal fetuses with no visibl e defects on scan, four had anomalies diagnosed after birth. Among the chromosomally normal singletons, six of 22 with other anomalies seen on scan and seven of 38 with no other visible defects on scan had intr auterine growth retardation. Among chromosomally normal twins, one of two with other anomalies seen and two of five appearing otherwise norm al had intrauterine growth retardation; one twin set was delivered at 23 weeks after the demise of both twins. Karyotyping is recommended wh enever a two-vessel cord is seen in association with symmetric intraut erine growth retardation or any other defect. The fetus diagnosed with a two-vessel cord and any other anomaly by ultrasound often has addit ional structural defects not seen on scan. The fetus with an isolated two-vessel cord on scan seldom has unrecognized major anomalies, but i s at risk for intrauterine growth retardation.