Inherent fragility of zona pellucida in certain patients included in an in-vitro fertilization programme

OOcytes with a fractured zona pellucida were previously reported to occur with a 16% frequency when follicle puncture was carried out using a 20-ml syringe. This paper demonstrates a high rate of recurrence of fractured zonae in certain patients included in an in-vitro fertilization programme. We hypothesize an inherent zona fragility affecting these patients.