Healthy twin delivery after day 7 blastocyst transfer coupled with assisted hatching

To report a normal twin delivery after transfer of two fresh day 7 blastocysts.

Case report.

Private infertility clinic.

A 35-year-old woman with a 6-year history of primary infertility with significant pelvic adhesions.

Review of individual IVF-ET therapy cycle.

Full-term delivery after day 7 blastocyst transfer.

During the patient's first IVF-ET cycle, the decision was made to undertake blastocyst transfer after extended culture. No blastocysts had formed until late on day 6, by which time the patient had been hospitalized with a renal stone. Subsequently, on day 7, the patient was asymptomatic and presented for embryo transfer, and after assisted hatching, two expanded blastocysts were transferred to her uterus under ultrasound guidance. After confirmation of implantation of a viable twin, pregnancy was uneventful with no obstetrical complications, and a dizygotic twin was delivered vaginally at 38 weeks of gestation.

Few reports have been made regarding viability of more slowly developing blastocysts; however, this case indicates that blastocysts that did not fully expand until day 7 of extended in vitro culture are still able to implant after superovulation and IVF-ET therapy. Assisted hatching of these embryos may have been beneficial in achieving this successful outcome by hastening the blastocyst hatching, allowing more rapid contact with the endometrium.