Preimplantation embryos sex ratios in couples with four or more children of same sex, what should be expected from a preimplantation genetic diagnosis cycle?

Our aim was to assess the preimplantation embryos’ sex ratios in couples with four or more children of same sex, undergoing sex selection for nonmedical reasons. We conducted a cohort-historical study of all consecutive patients admitted to the IVF-PGD program in a large tertiary center. We reviewed the computerized files of all consecutive women admitted to our IVF for sex selection for nonmedical reasons. Patients and their PGD cycle characteristics were compared according to the desired sex of their embryo and the mode of fertilization. Nine patients underwent a total of 19 PGD cycle attempts during the study period. Of the 77 embryos with complete molecular diagnosis, 41 revealed a male embryo and 36 a female embryo. Thirty-five percent of all the diagnosed embryos were of the desired sex. For couples desiring a boy, IVF cycles achieved a higher ratio of the desired embryonal sex compared to ICSI (52% vs 18.7%, p =.03). For couples desiring a girl, ICSI cycles had a higher percentage of the desired embryonal sex compared to IVF cycles (38% vs 23%). Moreover, 29.7% of ICSI and 40% of IVF embryos achieved the desired sex. In conclusion, PGD for sex selection results in a relatively low percentage (35%) of embryos demonstrating the desired sex. Nonetheless, selecting the mode of fertilization (ICSI/IVF) might improve the success rate. Further studies are required to explore the appropriate and cost-effective method for sex selection for nonmedical reasons.