Neonatal outcome after vitrified day 3 embryo transfers: a preliminary study.

OBJECTIVE: To compare and evaluate the neonatal outcome in infants born after vitrified day 3 embryo transfers with that of fresh day 3 embryo transfers.

DESIGN: Retrospective analysis.

SETTING: Private assisted reproductive center.

PATIENT(S): Sixty-nine women, who delivered 89 babies.

INTERVENTION(S): Surplus day 3 cleavage stage embryos were vitrified using ethylene glycol-based solution by cryoloop carrier system and transferred after warming.

MAIN OUTCOME MEASURE(S): Post-thaw survival of embryos, implantation and pregnancy rates (PR), neonatal outcome, and congenital birth defects.

RESULT(S): A total of 907 vitrified day 3 embryos from 285 cycles were warmed and 817 survived (90.37%), which were used for embryo transfer. The pregnancy, implantation, miscarriage, and live birth rates achieved were 36.84%, 18.11%, 7.71%, and 24.21%, respectively. Of the 69 deliveries, singleton, twins, and triplets comprised of 72.46%, 26.08%, 1.44%, respectively, and 8 (11.59%) were preterm deliveries. The mean Apgar scores were 8.3, 9.2, 9.4 at 1, 5, and 10 minutes. The congenital birth defect rate was 1.18%. These results were comparable with pregnancies using fresh embryo transfers.

CONCLUSION(S): This preliminary study shows that vitrification is an efficient method of cryopreservation of human day 3 embryos with neonatal outcome comparable to fresh embryo transfers.