Dizygotic twin from conjoined oocytes: a case report.

Purpose: Binovular follicles including a pair of conjoined oocytes within a common zona pellucida or their fusion in the zonal region gained some attentions due to its possible role in dizygotic twins. Although some cases in the literature been reported in which two conjoined oocytes arising from binovular follicles were mature, and injected with two separated sperm, no available evidence reported for dizygotic twin pregnancies.
Methods: A case report of a 37-year-old female patient underwent embryo transfer cycle whereby a pair of conjoined blastocysts after ICSI of a pair of conjoined oocytes was transferred.
Results: The β-hCG level was positive 15 days after embryo transfer. The subsequent pregnancy scan revealed a dizygotic pregnancy. The woman gave birth to two healthy boys in the mid of 38 weeks of gestation by cesarean section.
Conclusions: Given the insufficient evidence on how to handle conjoined oocytes, this report acknowledges the first occurrence of dizygotic twin delivery resulted from transfer of a pair of conjoined blastocysts after ICSI of a pair of conjoined oocytes. This also confirms that we should be extremely conservative in discarding any mature oocyte without sufficient data about its useless future to result in a healthy baby.