Assisted hatching increases the implantation and pregnancy rate of in vitro fertilization (IVF)-embryo transfer (ET), but not that of IVF-tubal ET in patients with repeated IVF failures.

OBJECTIVE

To assess the effect of augmenting IVF with assisted hatching in the treatment of patients with repeated IVF failures.

DESIGN

Prospective randomized study.

SETTING

Division of Reproductive Endocrinology and Infertility of National Taiwan University Hospital.

PATIENT(S): From July 1993 to February 1996, 49 patients with repeatedly failed IVF were treated with assisted hatching and were compared with 51 control subjects without assisted hatching.

INTERVENTION(S): Assisted hatching.

MAIN OUTCOME MEASURE(S): Pregnancy rate and implantation rate per embryo after IVF-ET or IVF-tubal ET (TET) were measured.

RESULT(S): The pregnancy rate (PR) in the assisted hatching group was found to be 36.7% compared with 19.6% in the control group, but the difference was not significant. When only patients receiving IVF-ET were considered, it was observed that the PR was significantly higher in the assisted hatching group than the control group (42.4% versus 16.1%). With IVF-TET however, the PR was found to be similar in both assisted hatching and control groups (25.0% and 25.0%, respectively). The rate of embryonic implantation in the IVF-ET patients was 11.0%, which was significantly higher than that of control embryos (3.7%).

CONCLUSION(S): These results implied that IVF-ET, combined with assisted hatching, may improve the PR and implantation rate in patients with repeated IVF failures, but the same was not true in the case of IVF-TET.