The American Society for Reproductive Medicine (ASRM) has just published an article about the role of assisted hatching in IVF.

Hatching of the blastocyst is a critical step in the sequence of physiologic events culminating in implantation. Failure to hatch, due to intrinsic abnormalities in either the blastocyst or zona pellucida, may be the reason for failing to implant. The assisted hatching consists in making a hole or thinning the zona pellucida.

However, a systematic review published by the Cochrane Collaboration showed that after evaluating 31 randomized controlled trials, there is no evidence about its effectiveness yet. Live birth rates haven’t increased with assisted hatching. There are some doubts about the effectiveness of this intervention in some specifics subgroups of patients (poor prognosis, repetitive failures) because some studies showed an increase in pregnancy rates (although no increase in live birth rates were seen). More studies are necessary to obtain definitive conclusions.