A prospective, randomized, double-blind study for the evaluation of assisted hatching in patients with advanced maternal age

The objective of this study was to determine if assisted hatching improvedthe rates of implantation, clinical pregnancy and ongoing pregnancy forin-vitro fertilization (IVF) patients aged > or =36 years. On the day ofoocyte aspiration, consenting patients were randomized according to whetherall embryos underwent the hatching procedure (hatched; n = 41) or allembryos remained unhatched (controls; n = 48). Patients in both groups weretreated with methylprednisolone and doxycycline starting on the day ofoocyte retrieval and continuing for 4 days. The hatching procedure wasperformed approximately 55 h after insemination on all potential embryosfor transfer and employed the release of acidified acid Tyrode's mediumagainst the zona pellucida to create an opening approximately 20 microm indiameter. No significant differences were noted in the mean age, number ofoocytes aspirated and number of embryos transferred between the hatched andcontrol groups. In addition, no significant differences were observed inthe rates of implantation (11.1 versus 11.3%), clinical pregnancy (39.0versus 41.7%) and ongoing pregnancy (29.3 versus 35.4%) between the hatchedand control groups respectively. These results suggest that assistedhatching may have no significant impact on IVF success rates in the patientpopulation studied.