Enhancing the scope of in vitro maturation for fertility preservation: transvaginal retrieval of immature oocytes during endoscopic gynaecological procedures.

Study Question: Could in vitro maturation (IVM) following transvaginal oocyte retrieval during gynaecological surgery (IVM-surgery) be an effective and safe strategy for fertility preservation?

Summary Answer: IVM-surgery on unstimulated ovaries is a novel option that can be considered for fertility preservation for women requiring gynaecological surgery, but more research is needed to identify appropriate patients who may benefit and to determine the cost-effectiveness of such an approach.

What Is Known Already: IVM followed by oocyte/embryo cryopreservation has been useful as a safe reproductive strategy for some infertile women.

Study Design, Size, Duration: This prospective cohort study comprised 158 consecutive women with polycystic ovary syndrome (PCOS) who underwent laparoscopy or hysteroscopy for other reasons and had concomitant transvaginal oocyte retrieval followed by IVM between 2014 and 2016.

Participants/materials, Setting, Methods: A total of 158 women with anovulatory PCOS who underwent IVM-surgery in our infertility centre were recruited for this study. Matured IVM oocytes obtained from these women were either freshly fertilized and subsequently frozen at the blastocyst stage (fresh oocyte group, n = 46) or the oocytes were frozen (frozen oocyte group, n = 112) for fertility preservation followed by later thawing for insemination and cleavage embryo transfer (ET) (n = 33). The following outcomes were then evaluated: embryological data, clinical pregnancy rate, live birth rate (LBR), neonatal outcomes, post-operative complications and post-operative ovarian function.

Main Results And The Role Of Chance: Among all the women who underwent IVM-surgery, the clinical pregnancy rate and LBR per initiated IVM cycle were 9.5% (15/158) and 6.9% (11/158), respectively. Women (40.6%, 20/33) who underwent the procedure with frozen-thawed oocytes (oocyte survival rate, 83.0%) obtained a high quality of cleaved embryos. In the fresh oocyte group, the clinical pregnancy rate and LBR per ET cycle were 69.2 and 53.8%, respectively. In the frozen oocyte group, the clinical pregnancy rate and LBR per ET cycle were 28.6 and 19.1%, respectively. No adverse neonatal outcomes were recorded. IVM-surgery was not associated with post-operative complications, a longer hospital stay, or impaired ovarian function.

Limitations, Reasons For Caution: Because of the small sample size and the low utilization rate and cost-effectiveness per retrieval, the present findings should be interpreted with caution, and further studies are needed for the long-term follow-up of live births.

Wider Implications Of The Findings: This strategy can also help patients with normal ovulation to obtain available oocytes and embryos for cryopreservation and subsequent use.

Study Funding/competing Interest(s): This research was supported by the Joint Research Fund for Overseas Natural Science of China (No. 31429004), the National Key Research and Development Program of China (No. 2017YFC1002000, 2017YFC1001504, 2016YFC1000302), the Ministry of Science and Technology of China Grants (No. 2014CB943203), the Chinese Society of Reproductive Medicine Fund (No. 16020400656) and the National Natural Science Foundation of China (No. 81300456). All the authors have nothing to disclose in terms of conflicts of interest.

Trial Registration Number: chictr-ONC-17011861.