Autologous Mitochondrial Transfer Does Not Improve Oocyte, Embryo Quality in Patients Undergoing IVF: Presented at ESHRE

By Chris Berrie

BARCELONA, Spain -- July 9, 2018 -- Autologous mitochondrial transfer (AUGMENT) does not improve oocyte or embryo quality, or pregnancy rates, compared with no transfer in women with previously failed in vitro fertilisation/intracytoplasmic sperm injection (IVF/ICSI), according to a study presented here at the 34th Annual Meeting of the European Society for Human Reproduction and Embryology (ESHRE).

“The mitochondria are the most abundant organelles in the mammalian oocyte, and they have a crucial role in providing ATP that is essential for fertilisation and early embryo development,” said E. Labarta Demur, MD, IVI RMA Valencia, Human Reproduction, Valencia, Spain.

Although donor oocyte cytoplasm transfer has been shown to potentially alleviate this problem, with live births obtained, the concerns with heteroplasmy did not allow this to go further. An alternative might be to provide autologous mitochondria from another source -- ovarian stem cells.

The current study included women (mean age, 36.3 years) with a mean 2.5 failed IVF cycles who were undergoing embryo screening for further IVF/ICSI. All women also underwent laparoscopic biopsy of the ovarian cortex under anaesthesia for isolation of autologous mitochondria.

Sibling MII oocytes were obtained after stimulation and were allocated though computerised randomisation to the AUGMENT protocol or conventional ICSI. An interim analysis was performed in 59 patients.

Two of 59 enrolled patients spontaneously conceived (1 ended in miscarriage). A total of 57 ovarian cortex biopsies were performed.

In the experimental group, 1-2 picoliters of mitochondrial suspension were injected along with the sperm during ICSI. Viable blastocysts from both groups were biopsied and cryopreserved.

A total of 26 patients did not undergo embryo transfer due to having no blastocysts available for biopsy (n = 16), all aneuploid (n = 8), no fertilization (n = 1), and no survival after thawing (n = 1).

A total of 253 MII were inseminated in the AUGMENT group and 250 in the control group, with a fertilization rate of 64.0 % and 70.8%, respectively (P = .11).

Day 5 blastocyst formation rates were significantly reduced in the AUGMENT group (27.2%) compared with the control group (43.5%; P = .002. The number of euploid blastocysts/biopsied blastocysts was 42.2% (19/45) in the AUGMENT group and 50% (37/74) in the control group (P = .42).

There was a statistically significant difference in euploidy rate/MII oocytes between both groups (7.5% vs. 14.8%; P = .01). No differences were observed regarding mtDNA content in euploid embryos.

The live birth rate per transferred embryo was 41.2% (7/17) in the AUGMENT group and 39.1% (9/23) in the control group (P = .90).

“[Autologous mitochondrial transfer] does not seem to improve oocyte and embryo quality in these poor prognosis patients, with the ratio of euploid embryos obtained per MII oocyte significantly lower with [this procedure],” concluded Dr. Demur.

Funding for this study was provided by OvaScience.[Presentation title: Autologous Mitochondrial Transfer as a Complementary Technique to ICSI to Improve Oocyte and Embryo Quality in IVF Patients. A Randomized Pilot Study. Abstract O-210]

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