Sonographic detection of the umbilical cord insertion site at 11–14 gestational weeks

Ziel: Anomalous insertions of the umbilical cord and especially Insertio velamentosa, which appears in 1% of singleton pregnancies, are associated with several obstetrical complications such as IUGR, preterm birth, low APGAR scores, fetal bleeding and retention of the placenta. Localization of the insertion site of the umbilical cord is not part of the routine ultrasound screening at 11–14 weeks. In this study we wanted to investigate the detection rate of umbilical cord insertion anomalies at 11–14 weeks and evaluate the sensitivity and specificity of this screening method.

Methodik: In this prospective observational study between April 2008 and August 2009 we consecutively included all patients that had an ultrasound examination between 11–14 weeks and also delivered at our hospital. 487 fetuses from singleton and twin pregnancies were examined and the umbilical cord insertion was documented with 2-D ultrasound. The postpartum insertion was evaluated according to birth records and to pathology reports.

Ergebnis: 322 fetuses had a reliable documentation of the umbilical cord insertion at birth and were included into the study group.The insertion site was correctly detected in 80% of the cases with 2 D sonography at 11–14 weeks. In our study group we had 64 anomalous cord insertions and 35 cases of insertio velamentosa. Sensitivity of the detection of an anomalous insertion site at 11–14 weeks was 62% and the specificity was 85%.

Schlussfolgerung: Sonographic screening for the umbilical cord insertion is useful for the exclusion of anomalous insertions in early pregnancy. If the insertion site is anomalous, close monitoring during pregnancy is needed in order to prevent associated complications and intervene if necessary. The low sensitivity of this examination is most likely due to the fact that the insertion of the umbilical cord can normalize during the course of pregnancy. To evaluate and prove this phenomenon sonographic studies during the second and third trimester are needed.