Monochorionic diamniotic twin pregnancy in a didelphys uterus

Case contributed by Dr Alexandra Stanislavsky


Early pregnancy. Patient presenting for a viability and dating ultrasound.

Patient Data

Gender: Female

Two distinct uterine bodies are present. Within the left uterus, there is a single gestational sac containing two fetal poles - each accompanied by a yolk sac and each clearly surrounded by a separate amnion - the two amnions having not yet fused to form a single intertwin membrane.

Concordant size of the two embryos, each generating a gestational age of 8 weeks 3 days. In both, cardiac activity is demonstrated.  

A corpus luteum is present on the left side - as expected, given that the pregnancy is in the left uterus.

Case Discussion

There is clearly a Mullerian duct anomaly, with two uterine bodies being separated by a deep cleft. There appear to be two separate cervices (first image of the static series). Although no coronal imaging is available to confirm this, the appearance is of a didelphys uterus.

Within the left uterine horn, there is a normal early monochorionic diamniotic pregnancy, with beautifully demonstrated separation of the two embryos by the as yet unfused amniotic sacs.

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Case information

rID: 68304
Published: 25th May 2019
Last edited: 23rd Jun 2019
Inclusion in quiz mode: Included

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