Successful ongoing pregnancies after vitrification of oocytes

Objective

To demonstrate the efficiency of vitrifying mature human oocytes for different clinical indications.

Design

Descriptive case series.

Setting

Cryobiology laboratory, Centro Colombiano de Fertilidad y Esterilidad–CECOLFES LTDA. (Bogotá, Colombia).

Patient(s)

Oocyte vitrification was offered as an alternative management for patients undergoing infertility treatment because of ovarian hyperstimulation syndrome, premature ovarian failure, natural ovarian failure, male factor, poor response, or oocyte donation. Mature oocytes were obtained from 33 donor women and 40 patients undergoing infertility treatment.

Intervention(s)

Oocytes were retrieved by ultrasound-guided transvaginal aspiration and vitrified with the Cryotops method, with 30% ethylene glycol, 30% dimethyl sulfoxide, and 0.5 mol/L sucrose. Viability was assessed 3 hours after thawing. The surviving oocytes were inseminated by intracytoplasmic sperm injection. Fertilization was evaluated after 24 hours. The zygotes were further cultured in vitro for up to 72 hours until time of embryo transfer.

Main Outcome Measure(s)

Recovery, viability, fertilization, and pregnancy rates.

Result(s)

Oocyte vitrification with the Cryotop method resulted in high rates of recovery, viability, fertilization, cleavage, and ongoing pregnancy.

Conclusion(s)

Vitrification with the Cryotop method is an efficient, fast, and economical method for oocyte cryopreservation that offers high rates of survival, fertilization, embryo development, and ongoing normal pregnancies, providing a new alternative for the management of female infertility.

Key Words:  Oocyte , vitrification , survival , pregnancy , ICSI , cryopreservation , cryobank