Abstract

This study examines the use of ultrasound in pregnancy to find the site of umbilical cord insertion into the placenta, and compared these findings with the umbilical cord insertion site in the placenta after delivery. It involved 277 pregnancies in a large maternity centre. Ultrasound scans were performed between 10 and 14, 18 and 22, and 32 and 34 weeks of pregnancy. The umbilical cord insertion site on the placenta was identified and the shortest distance to the edge of the placenta was measured. Images of the placentas after delivery were taken and digitally measured. The accuracy and ability of these tests to identify the umbilical cord insertion site were calculated and compared to the actual umbilical cord insertion site of the delivered placentas. An atypical umbilical cord insertion site (located less than 2cm from the edge of the placenta) was found in 30 placentas at delivery. 102 (37%) of umbilical cord insertions were considered atypical in the first trimester, 43 (16%) in the second trimester, and 28 (10%) in the third trimester. The accuracy of this ultrasound test was highest in the second trimester. The rate of atypical umbilical cord insertion is overestimated in the first trimester.