EP14.19: Sonographic diagnosis of first trimester umbilical cord entanglement in monochorionic monoamniotic twins: case report and review of the literature

A 32-year-old gravida 2 para 1 woman underwent a transvaginal ultrasound (US) examination at 8.5 gestational weeks. Two embryos and one yolk sac were demonstrated in the same amniotic sac. The fetal Crown–rump lengths were 20 and 21 mm, appropriate for 8.4 and 8.5 weeks, respectively. Two tightly entangled umbilical cords of the fetuses were demonstrated by 3D HD power Doppler flow (see figure 1). Spectral Doppler US showed two different heart rates (162 and 167 BMP) and blood flow in opposite directions. This was consistent with a diagnosis of a first trimester monochorionic monoamniotic (MCMA) twin pregnancy with umbilical cord entanglement (UCE). Missed abortion of the two embryos was diagnosed by US examination at 10.5 weeks, and the pregnancy was terminated. In a review of the seven cases (including ours) reported in the literature of UCE in the first trimester, the sonographic diagnosis was performed between the 8th and 13th weeks. The earliest sonographic diagnosis of UCE was at 8 W (present case). Four of the 7 cases had missed abortion of both fetuses simultaneously (57%). One was at the 10th week and 3 at 14-19 W. In 3 of the 7 cases (43%), the patient gave birth to two healthy newborns. In conclusion, UCE in MCMA twin pregnancy may occur in the first trimester as early as eight gestational weeks, and its diagnosis by ultrasound is feasible. UCE diagnosed in the first trimester may be a poor prognostic factor. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.