P-411 Cumulative live-birth rate after oocyte vitrification for fertility preservation (FP) in oncologic or benign conditions: a retrospective comparative monocentric study
Authors: Dreyfuss J , Sadoun M , Boumerdassi Y , Sritharan N , Eustache F , Sarandi S , Rakrouki S , Vinolas C , Sifer C , Grynberg M , Peigné M 
Published: June 2023

Abstract

Study question
Does cumulative livebirth-rate (CLBR) after reutilization of vitrified oocytes differ between patients having undergone fertility preservation (FP) for oncologic (onco-FP) reason or benign conditions (benign-FP)?

Summary answer
Although CLBR per woman was lower in the onco-FP group, there was no statistically significant association in multivariate analysis between onco-FP and CLBR.

What is known already
Recent ESHRE guidelines reported oocyte vitrification after controlled ovarian hyperstimulation (COH) as an established option for FP. Although age at the time of oocyte vitrification remains the main predictive factor of success, several lines of evidence suggest that the use of COH or in vitro maturation (IVM), as well as the indication of FP, in particular the type of disease, may influence outcomes after devitrification. The present investigation aimed at clarifying this issue.

Study design, size, duration
Observational comparative, monocentric retrospective study including all patients having reused, between January 2014 and December 2021, their oocytes vitrified for oncologic or benign conditions between 2013 and 2021. Women having undergone FP for non-medical indication were excluded.

Participants/materials, setting, methods
Among the 2201 patients having vitrified their oocytes, 94 (4.7%) returned for reutilization. The primary objective was the comparison of CLBR between onco-FP (n = 48) and benign-FP (n = 46) groups. A logistic model was performed. Factors associated with the CLBR in univariate analysis were included in a multivariate model. A secondary analysis was performed, comparing the benign-FP group and 2 groups of onco-FP according to the use of COH (Onco-COH, n = 25) or in-vitro maturation (Onco-IVM, n = 23).

Main results and the role of chance
Overall, in comparison with benign FP, women with malignant diseases were younger (median [IQR]: 34.0 y [31.0;37.0] vs. 36.5 y [33.2;38.0], p = 0.04) and had fewer oocytes vitrified (median [IQR]: 6.0 [3.0;9.2] vs.15.5 [6.2;18.0]), p &lt; 0.001). The CLBR in onco-FP and benign-FP groups were 14.6% (7/48), and 32.6% (15/46), respectively. In univariate analysis, the CLBR was significantly lower in the onco-FP group when compared with the benign-FP group: (OR [95%CI]: 0.35 [0.12;0.94], p = 0.04). However, this difference in the CLBR did not reach significance after multivariate analysis (OR [95%CI]: 0.38 [0.09;1.51], p = 0.18). As expected, age at the time of oocyte vitrification was negatively associated with CLBR (OR [95%CI]: 0.80 [0.67;0.92], p = 0.005), while the number of oocytes inseminated was positively related to CLBR (OR [95%CI]: 1.22 [1.08;1.40], p = 0.002).
Unlike onco-COH, onco-IVM was associated with a significant decrease in CLBR when compared to benign-FP (only COH), in univariate analysis: 8.7% (OR [95%CI]: 0.20 [0.03;0.80], p = 0.04), without significance after multivariate analysis (OR [95%CI]: 0.37 [0.04;2.16], p = 0.29).The livebirth rate (LBR) per oocyte was 2.1% in the onco-IVM subgroup (3 babies for 141 oocytes thawed), 2.7% in the onco-COH subgroup (7 babies for 260 oocytes thawed) and 3.7% (18 babies for 479 oocytes thawed) in the benign-FP group.

Limitations, reasons for caution
The small size of our population was probably responsible for a lack of statistical power. The retrospective and monocentric nature of our study may also be a weakness. Furthermore, LBR per oocyte was analyzed without age-adjustment.

Wider implications of the findings
This study provides actual data on chances of achieving a livebirth after oocyte vitrification, according to the use of a COH or IVM and the context of FP, oncologic or benign conditions.

Trial registration number
not applicable