Oocyte vitrification does not increase the risk of embryonic aneuploidy or diminish the implantation potential of blastocysts created after intracytoplasmic sperm injection: a novel, paired randomized controlled trial using DNA fingerprinting

Capsule:
Using a novel, paired study design, this RCT demonstrates that blastocysts derived from previously vitrified oocytes are not at an increased risk of aneuploidy and have equivalent reproductive potential.

Authors:
Eric J. Forman, M.D., Xinying Li, Ph.D., Kathleen M. Ferry, B.S., Katherine Scott, M.S., Nathan R. Treff, Ph.D., Richard T. Scott Jr., M.D.

Volume 98, Issue 3, Pages 644-649, September 2012

Abstract:

Objective:
To assess the impact of oocyte vitrification on aneuploidy and reproductive potential by comparing vitrified and control oocytes from a single patient within a single cycle and a single fresh transfer.

Design:
Paired RCT in which each patient’s cohort of mature oocytes was divided into two even groups with half undergoing Cryotop vitrification and rapid warming, and half serving as controls.

Setting:
Academic center for reproductive medicine.

Patient(s):
Forty-four patients with a mean age of 29.9 ± 2.3 years and normal ovarian reserve.

Intervention(s):
Cryotop vitrification of half of mature oocytes. Trophectoderm biopsy with SNP microarray analysis for ploidy and DNA fingerprinting.

Main Outcome Measure(s):
Rate of aneuploidy (primary outcome), fertilization, cleavage, blastulation and implantation in embryos derived from vitrified and control oocytes.

Results:
A total of 588 mature oocytes were randomized with 240/294 (81.6%) surviving vitrification. Amongst surviving vitrified oocytes, there was a lower fertilization rate with ICSI (77.9% vs. 90.5%, RR 0.86, 95% CI 0.80-0.93, P

Conclusions:
Although the IVF process is less efficient following oocyte vitrification, implantation rates are equivalent and there is not an increased risk of aneuploidy. Given the lack of other viable options, this study provides great reassurance to patients and clinicians applying oocyte vitrification for fertility preservation.

Support:
Reproductive Medicine Associates of New Jersey

ClinicalTrials.gov Identifier:
NCT01223118

  • kivan

    Yes, its great to see well designed studies such as this one that go beyond the evaluation of the efficacy and clinical efficiency of oocyte vitrification to evaluate the safety of the process for patients and their offspring. It’s reassuring to see that the meiotic machinery apparently remains intact following oocyte vitrification and warming.

  • Ana Cobo

    I agree with all the previous comments. In
    my opinion this work has a tremendous impact for the definitive validation of
    oocyte vitrification and the full establishment egg-banking. However, the
    decrease in the potential of vitrified oocytes is debatable and must be
    evaluated under specific contexts.

  • laurenwroth

    I agree with prior poster that this is a great study design (used again for a very informative study). Although the study does point out the decreased reproductive potential of vitrified/ thawed oocytes, it is reassuring that oocytes that do fertilize and develop into blasts have an equivalent chance of producing an ongoing pregnancy.

  • Micah Hill

    Another study from this group where they randomized embryos or oocytes within a single patient’s cohort into two treatment groups. A very impressive and novel study design which takes advantage of the uniqueness of ART for such a paired analysis. This data gives very nice information to counsel patients undergoing vitrification and highlights a decreased reproductive efficiency in such oocytes. I think its important to remember that these were young, good prognosis patients and may not apply to all patients undergoing vitrification. Overall amazing study very well designed to answer the main objective.

Translate »