Reduced oxygen tension improves embryo quality but not clinical pregnancy rates: a randomized clinical study into ovum donation cycles

The use of reduced oxygen tension during in vitro culture improves embryo quality but does not affect ongoing pregnancy rates in ovum donation cycles.

Like Comment

Authors

Maria J. de los Santos, Ph.D., Pilar Gámiz, Ph.D., Carmela Albert, Ph.D., Arancha Galán, Ph.D., Thamara Viloria, Ph.D., Sonia Pérez, Ph.D., Josep Ll. Romero, Ph.D., José Remohí, M.D.

Volume 100, Issue 2, Pages 402-407, August 2013

Abstract

Objective:

To investigate the effect of low O2 tension during in vitro culture in terms of ongoing pregnancy rates in ovum donation cycles.

Design:

Randomized trial.

Setting:

Private university-affiliated IVF center, university-based hospital.

Patient(s):

A total of 1,125 cycles of ovum donation.

Intervention(s):

Embryo culture in an atmosphere of 5.5% CO2, 6% O2, and 88.5% N2 versus a dual-gas system of 5.5% CO2 in air.

Main Outcome Measure(s):

Ongoing clinical pregnancy rates per intention-to-treat (ITT) patients.

Result(s):

The use of low O2 tension achieved a 41.3% ongoing pregnancy rate per ITT compared with a 40.8% rate obtained for 5% CO2 in air. The mean number of blastomeres and the percentage of top-quality embryos were significantly higher after lower O2 concentration during in vitro culture (7.1 ± 3.6 and 28.6% vs. 7.3 ± 8.4 and 32.1%, respectively).

Conclusion(s):

In the ovum donation cycles undergoing day-3 embryo transfers, the use of low O2 tension did not improve ongoing pregnancy rates per cycle and per transfer. However, it benefited embryo quality, demonstrating the potential negative impact of high O2 tension on the in vitro embryo development.

Read the full text at: http://www.fertstert.org/article/S0015-0282(13)00460-3/fulltext


Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders. The journal publishes juried original scientific articles in clinical and laboratory research relevant to reproductive endocrinology, urology, andrology, physiology, immunology, genetics, contraception, and menopause. Fertility and Sterility® encourages and supports meaningful basic and clinical research, and facilitates and promotes excellence in professional education, in the field of reproductive medicine.

No comments yet.