Could fertility clinics offer a sizable improvement of live birth rates by maturing post-GVBD oocytes in vitro?
The objective of this study is to analyze the potential of immature, denuded, post-GVBD (germinal vesicle breakdown) oocytes (including prometaphase I, metaphase I, and prometaphase II stages) to result live birth after in vitro maturation. Furthermore, we compared two culture media to identify which of them provides better reproductive outcomes when used for in vitro maturation.
We performed a retrospective cohort study including 4022 IVF-ICSI (in vitro fertilization-intracytoplasmic sperm injection) cycles between 2011 and 2015. A total of 4450 immature post-GVBD oocytes from 1442 cycles were cultured in vitro; of these, 2364 oocytes reached MII (metaphase II) stage (IVMC oocytes, in vitro meiotic completion) and were fertilized. Overall, 3933 embryo transfers were performed: 3579 were embryos derived from MII oocytes (ET-MII); 264 were embryos derived from MII + IVMC oocytes (ET-MIX), and 90 embryos from IVMC oocytes (ET-IVMC). In total, 399 IVMC embryos were transferred.
Maturation rate for immature post-GVBD oocytes was 54.1%. G-2™PLUS (Vitrolife) medium provided significantly higher maturation rate (p < 0.001) than G-IVF™PLUS (Vitrolife) (65.7% vs. 42.5%, p < 0.001). Embryos in ET-IVMC in cleavage stage had an average morphological score of 6.8/10 (7.7 in ET-MII; p < 0.001). Regarding reproductive outcomes, ET-IVMC gave 11.1% biochemical pregnancy rate, 10.0% clinical pregnancy rate, 7.8% ongoing pregnancy rate, and 5.6% live birth rate.
Embryos arising from IVMC oocytes resulted in a live birth rate of 5.6%. We suggest that in vitro maturation of denuded immature post-GVBD oocytes should be performed at the very least when few MII are collected, and likely in all patients, as they provide acceptable maturation and fertilization rates, and a sizeable increase in live birth.
KeywordsIVMC oocyte In vitro maturation Live birth Immature post-GVBD oocyte Culture medium
The authors wish to thank Sarai Brazal for her support with the database and Anna Ferrer-Vaquer for critical review of the manuscript.
N.M.: involved in study design, data analysis, and manuscript preparation. D.G.: involved in study design, data analysis, statistical analysis, and manuscript preparation. R.V. and A.R.: involved in study design, implementation, supervision, expert knowledge, and manuscript preparation.
Compliance with ethical standards
Ethical approval for performing this study was obtained from the institutional Ethics Committee for Clinical Research.
Conflict of interest
The authors declare that they have no conflict of interest.
- 11.Coroleu B, Barri PN, Carreras O, Belil I, Buxaderas R, Veiga A, et al. Effect of using an echogenic catheter for ultrasound-guided embryo transfer in an IVF programme: a prospective, randomized, controlled study. Hum Reprod. 2006;21(7):1809–15. https://doi.org/10.1093/humrep/del045.CrossRefGoogle Scholar
- 13.Dyrlund TF, Kirkegaard K, Poulsen ET, Sanggaard KW, Hindkjaer JJ, Kjems J, et al. Unconditioned commercial embryo culture media contain a large variety of non-declared proteins: a comprehensive proteomics analysis. Hum Reprod. 2014;29(11):2421–30. https://doi.org/10.1093/humrep/deu220.CrossRefGoogle Scholar
- 16.Jahromi BN, Mosallanezhad Z, Matloob N, Davari M, Ghobadifar MA. The potential role of granulosa cells in the maturation rate of immature human oocytes and embryo development: a co-culture study. Clin Exp Reprod Med. 2015;42(3):111–7. https://doi.org/10.5653/cerm.2015.42.3.111.CrossRefGoogle Scholar