• Anne Mayeur Le Bras, François Petit, Alexandra Benachi, Bettina Bedel, Salima Oucherif, Jelena Martinovic, Narjes Armanet, Lucie Tosca, Valérie Gautier, Frédéric Parisot, Philippe Labrune, Gérard Tachdjian, and Sophie Brisset.
• Service d'Histologie Embryologie et Cytogénétique, Hôpitaux Universitaires Paris Sud, Site Antoine Béclère, APHP, Clamart, France.
• Birth Defects Res. Part A Clin. Mol. Teratol. 2016 Apr 1; 106 (4): 298-303.

BackgroundMonochorionic twins are generally considered as a monozygotic twin pregnancy. However, several cases of monochorial dizygotic twin pregnancies have been reported.Case ReportWe report on a rare case of monochorionic dizygotic twin pregnancy conceived after induced ovulation in a 32-year-old woman. The diagnosis was made on morphological ultrasound examination at 18+4 weeks of gestation, showing two fetuses with discordant sex. The amniocentesis was declined by the patient.ResultsThe monochorionic status was confirmed after a histopathalogical study of the placenta. At delivery, both a phenotypically normal boy and a phenotypically normal girl without sexual abnormality were observed. This analysis also revealed the presence of vascular anastomoses between both fetal circulations. Postnatal cytogenetic analyses indicated the presence of a chimerism in peripheral blood lymphocytes. This chimerism was not observed in cells obtained from a buccal swab. Molecular determination of zygosity confirmed the existence of the confined peripheral blood chimerism with the presence of four parental alleles.ConclusionWe report on a case of monochorionic dizygotic twin pregnancy. This observation underlies the need to carefully assess twin pregnancies, especially when obtained after assisted reproductive technology.© 2016 Wiley Periodicals, Inc.

11 keywords...

hide…