A CASE REPORT OF CONJOINED CEPHALOPAGUS TWINS DIAGNOSED AT 7 WEEKS GESTATIONAL AGE FOLLOWING IVF/ICSI

To describe a case report of cephalopagus conjoined twins following a single embryo transfer diagnosed at 7 weeks gestational age Case report of a 35 year old G0 who proceeded with IVF for a history of male factor infertility. Following single embryo transfer the patient was diagnosed with a conjoined twin pregnancy. During her IVF cycle, the patient was stimulated with an antagonist protocol for 13 days followed by a gonadotropin-releasing hormone (GnRH) agonist trigger. Thirteen eggs were retrieved, 9 were mature, and 5 fertilized with ICSI. Of those, two were cryopreserved. She had a successful frozen blastocyst embryo transfer. The patient’s seven week ultrasound demonstrated a single gestational sac, yolk sac, and fetal pole. However, the crown-rump length appeared visually abnormal and two heart beats were visualized. She was referred to maternal-fetal medicine (MFM) for a first-trimester ultrasound. Her ultrasound with MFM was notable for a fluid filled chest, foreshortened limbs, and early sacral agenesis. She was subsequently diagnosed with cephalopagus twins and underwent an induced abortion following consultation with MFM. Assisted reproductive technology (ART) increases the risk of monozygotic twins threefold compared to spontaneous conception. A rare, but significant risk of monozygotic twinning is conjoined twins, with an incidence of 1 in 50,000 to 1 in 100,000. Given the low rates of both monozygotic twinning and conjoined twinning, it is challenging to elucidate the mechanism behind these conditions and how ART may play a role. This case report adds to the paucity of literature regarding conjoined twins following ART and, to our knowledge, is the earliest gestational age reported at diagnosis and the second reported case of cephalopagus following IVF.