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

OBJECTIVE: To report a normal twin delivery after transfer of two fresh day 7 blastocysts. DESIGN: Case report. SETTING: Private infertility clinic. PATIENT(S): A 35-year-old woman with a 6-year history of primary infertility with significant pelvic adhesions. INTERVENTION(S): Review of individual IVF-ET therapy cycle. MAIN OUTCOME MEASURE(S): Full-term delivery after day 7 blastocyst transfer. RESULT(S): 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. CONCLUSION(S): 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.

Estimation of second polar body retention rate after conventional insemination and intracytoplasmic sperm injection: in vitro observations from more than 5000 human oocytes.

PURPOSE: Tripronucleate (3pn) development after conventional insemination (CONV) or ICSI was analyzed to estimate the rate of second polar body retention giving rise to 3pn formation. METHODS: Data from 453 consecutive IVF cycles were reviewed during a 6-month period. Mature oocytes were monitored in ICSI (n = 3195) and CONV (n = 2274) groups by fertilization assessment 16-18 h post-insemination. Ovulation induction protocols and in vitro culture conditions remained constant during the study interval. RESULTS: Normal (2pn) fertilization occurred in 74.2% and 70.5% for CONV and ICSI groups, respectively (p < 0.003). 1pn formation was observed in 4.5% of CONV oocytes, and 2.5% of ICSI oocytes (p < 0.001); 3pn formation was 8.1% in the CONV group, and 2.5% in the ICSI group (p < 0.0001). We observed 4pn formation in 0.4% of oocytes in the CONV group, but in only 0.04% of oocytes fertilized with ICSI (p < 0.007). Cellular degeneration occurred in 2.4% of oocytes inseminated conventionally, and in 3.5% of oocytes fertilized by ICSI (p = 0.02). Maternal age did not impact pronuclear status. CONCLUSIONS: We found the 3pn formation rate after ICSI to be approximately one-third that observed in the CONV group. Extrapolating the ICSI data to the CONV data, it may be inferred that 2.5% of 3pn development after CONV was due to second polar body retention. This suggests that 5.6% of CONV oocytes showed dispermic fertilization. Decreasing oocyte quality with increasing maternal age had no apparent influence on any of the fertilization outcomes.