A case of Vascular Anastomoses in Dichorionic Diamniotic-Fused Placentas Resulting in

Kim, Min Joung; Lim, Si Yeon; Hur, Soo Young; Lee, Gui SeRa; Shin, Jong Chul; Kim, Soo Pyung; Rha, Jong Gu; Kim, Sa Jin

Case Report

Korean Journal of Obstetrics & Gynecology 2005;48(8):1971-1975.
Published online August 1, 2005.

A case of Vascular Anastomoses in Dichorionic Diamniotic-Fused Placentas Resulting in "Pseudo" Twin-to-Twin Transfusion Syndrome.

Min Joung Kim, Si Yeon Lim, Soo Young Hur, Gui SeRa Lee, Jong Chul Shin, Soo Pyung Kim, Jong Gu Rha, Sa Jin Kim

Department of Obstetrics and Gynecology, College of Medicine, Catholic University of Korea. ksajin@catholic.ac.kr

Abstract

Virtually all monochorionic twin placentas contain vascular connections between the circulatory domains of each twin. In contrast, vascular anastomoses are generally thought not to occur in fused, dichorionic placentation. In the twin-to-twin transfusion syndrome (TTTS) one twin is preferentially perfused by blood from the cotwin via unbalanced placental vascular anastomoses. This vascular shunting results in twins born with discrepant weights, colors and hemoglobins. When one of the TTTS criteria was not present, the pregnancy was defined as "pseudo" TTTS. In pregnancies complicated by "pseudo" TTTS indicate that small twins have abnormal cord insertion more frequently than large twins. We present a case of vascular anastomoses in dichorionic diamniotic-fused placentas resulting in "pseudo" TTTS with a brief review of the literatures concerned.

Key Words: Vascular anastomoses, "Pseudo" twin-to-twin transfusion syndrome