PLACENTAL CORD INSERTION VISUALIZATION WITH PRENATAL ULTRASONOGRAPHY

Color Doppler and gray scale sonography can be used prenatally to iden tify the location of the cord insertion into the placenta. The purpose s of this paper were to (1) relate sonographic identification of place ntal cord insertion with placental pathology; (2) evaluate the possibi lity that a marginal cord insertion may evolve into a velamentous cord insertion; and (3) determine the frequency and factors affecting sono graphic visualization of cord insertion. Our results show that the son ographic assessment of cord insertion correlated with the pathologic o utcome in 83% (106 of 128) of singleton preganncies and at least one o f the fetuses in 72% (8 of 11) of twin or triplet pregnancies. Althoug h the sensitivity for identification of an abnormal cord insertion was low (42%), the specificity was high (95%). Our data suggest that marg inal cord insertion evolved into velamentous cord insertion in one sin gleton and one twin. Our results showed that cord insertion was visual ized in 54% of fetuses scanned in a routine clinical practice. Cord in sertion visualization was possible at all gestational ages, although i t was more difficult at later gestational ages. In conclusion, this st udy provides evidence that (1) ultrasonography (either gray scale or c olor Doppler) is useful in identifying normal, marginal, and velamento us cord insertion; (2) marginal cord insertion may evolve into velamen tous cord insertion as pregnancy progresses; (3) in clinical practice the cord insertion site was visualized in just over half of the cases, and (4) prenatal identification of marginal and velamentous cord inse rtion potentially may be useful for planning obstetrical management.