[The impact of oocyte cryopreservation time in oocyte donation on the clinical success rate]. / Impact de la durée de cryoconservation ovocytaire dans le cadre du don d'ovocytes sur le taux de succès clinique.

OBJECTIVES: To evaluate the impact of the cryopreservation time of vitrified oocytes on the success rates in oocyte donation cycles. METHODS: A retrospective study was carried out on 156 cycles with donated oocytes from January 2012 to September 2021. All the cycles were sorted according to the storage time of the oocytes (25 in the group 1:<3 months, 32 in the group 2: between 3 and 6 months, 39 in the group 3: between 6 and 12 months, 38 in the group 4: between 12 and 24 months and 22 in the group 5:>24 months). Clinical outcomes after ART, survival rates at thawing and oocyte fertilization rates were compared between the different cohorts stratified according to oocyte storage duration. A binary multivariate logistic regression was performed adjusting for the identified confounders. RESULTS: Prolonged storage time of vitrified oocytes had an effect on their survival post-thawing rates, but no significant effect was identified on fertilization rates or clinical outcomes. After adjusting for the confounders, the relationships between clinical outcomes and oocytes storage time did not reach statistical significance. Our study was characterized by a limited cohort with data from a single ART center. CONCLUSIONS: Our study doesn't highlight any significant difference in the use of long-stored vitrified oocytes (more than 2 years) on clinical issues in ART. The conclusion of our study needs to be verified in further studies with larger cohorts.

Cell-free and intracellular nucleic acids: new non-invasive biomarkers to explore male infertility.

Male infertility is a devastating problem that affects many couples worldwide. However, the molecular mechanisms and causes of idiopathic male infertility remain unclear. Circulating cell-free nucleic acids have an important role in human physiology and emerging evidence suggests that they play a role in male infertility. This review summarizes recent results on cell-free and intracellular nucleic acids in male infertility and discusses their potential use as biomarkers of male infertility in the clinical practice.

L'infertilité masculine est un problème qui touche de nombreux couples. Cependant, aujourd'hui les mécanismes moléculaires et les causes de l'infertilité masculine idiopathique ne sont pas élucidés. Les acides nucléiques circulant ont un rôle important dans la physiologie et des évidences suggèrent qu'ils jouent un rôle dans l'infertilité masculine. L'objectif de cette revue est de mettre en avant les nouvelles avancées scientifiques sur les acides nucléiques circulant et non-circulant en lien avec l'infertilité masculine et de fournir une vue d'ensemble de leurs utilisation comme biomarqueurs en pratique clinique.

Sperm quality and paternal age: effect on blastocyst formation and pregnancy rates.

BACKGROUND: Several studies suggest a decrease in sperm quality in men in the last decades. Therefore, the aim of this work was to assess the influence of male factors (sperm quality and paternal age) on the outcomes of conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). METHODS: This retrospective study included all couples who underwent IVF or ICSI at Montpellier University Hospital, France, between 1 January 2010 and 31 December 2015. Exclusion criteria were cycles using surgically retrieved sperm or frozen sperm, with pre-implantation genetic diagnosis or using frozen oocytes. The primary outcomes were the blastulation rate (number of blastocysts obtained at day 5 or day 6/number of embryos in prolonged culture at day 3) and the clinical pregnancy rate. The secondary outcomes were the fertilization and early miscarriage rates. RESULTS: In total, 859 IVF and 1632 ICSI cycles were included in this study. The fertilization rate after ICSI was affected by oligospermia. Moreover, in ICSI, severe oligospermia (lower than 0.2 million/ml) led to a reduction of the blastulation rate. Reduced rapid progressive motility affected particularly IVF, with a decrease of the fertilization rate and number of embryos at day 2 when progressive motility was lower than 32%. Paternal age also had a negative effect. Although it was difficult to eliminate the bias linked to the woman's age, pregnancy rate was reduced in IVF and ICSI when the father was older than 51 and the mother older than 37 years. CONCLUSIONS: These results allow adjusting our strategies of fertilization technique and embryo transfer. In the case of severe oligospermia, transfer should be carried out at the cleaved embryo stage (day 2-3) due to the very low blastulation rate. When the man is older than 51 years, couples should be aware of the reduced success rate, especially if the woman is older than 37 years. Finally, promising research avenues should be explored, such as the quantification of free sperm DNA, to optimize the selection of male gametes.

CONTEXTE: De nombreuses données suggèrent une altération des paramètres spermatiques ces dernières décennies. Le but de ce travail est d'évaluer l'impact de facteurs masculins tels la qualité du sperme et l'âge paternel sur les résultats en fécondation in vitro classique (FIVc) et en fécondation in vitro avec injection intra-cytoplasmique de spermatozoïde (ICSI). MATÉRIELS ET MÉTHODES: L'étude a porté sur l'ensemble des couples ayant fait l'objet d'une tentative de FIVc ou d'ICSI entre le 1er janvier 2010 et le 31 décembre 2014 au CHU de Montpellier. Les critères d'exclusion ont été les tentatives avec utilisation de spermatozoïdes prélevés chirurgicalement ou de sperme congelé, les cycles avec diagnostic pré-implantatoire et les cycles avec ovocytes congelés. Au total, 859 ponctions de FIVc et 1632 ponctions d'ICSI ont été incluses dans l'étude. RÉSULTATS: En ICSI, le taux de fécondation est affecté par l'oligospermie. Par ailleurs, une oligospermie extrême (inférieure à 0,2 M/ml) entraîne une diminution du taux de blastulation. La mobilité progressive avant préparation a plus d'impact en FIVc, où les taux de fécondation et le nombre d'embryons obtenus à J2 vont être plus bas lorsque la mobilité progressive est inférieure à 32%. Même s'il est difficile d'éliminer le biais lié à l'âge de la partenaire, il semblerait qu'il y ait une diminution du taux de grossesse en FIVc et en ICSI à partir de 51 ans chez l'homme avec une partenaire âgée de plus de 37 ans. CONCLUSION: Ces résultats permettront essentiellement d'ajuster nos stratégies de choix de technique de mise en fécondation et de transfert. Pour les oligospermies extrêmes, il semble préférable de proposer un transfert précoce au stade embryon clivé (J2 - J3) car le taux de blastulation est très réduit dans ce cas. Lorsque l'homme est âgé, il faudra également informer le couple de la diminution des taux de réussite, d'autant plus si sa partenaire a plus de 37 ans. Enfin, différentes pistes prometteuses de recherche sont encore à explorer, comme le dosage de l'ADN libre spermatique afin d'optimiser la sélection des gamètes masculins et ainsi améliorer les résultats en AMP.

Cell-free DNA in Human Follicular Microenvironment: New Prognostic Biomarker to Predict in vitro Fertilization Outcomes.

Cell-free DNA (cfDNA) fragments, detected in blood and in other biological fluids, are released from apoptotic and/or necrotic cells. CfDNA is currently used as biomarker for the detection of many diseases such as some cancers and gynecological and obstetrics disorders. In this study, we investigated if cfDNA levels in follicular fluid (FF) samples from in vitro fertilization (IVF) patients, could be related to their ovarian reserve status, controlled ovarian stimulation (COS) protocols and IVF outcomes. Therefore, 117 FF samples were collected from women (n = 117) undergoing IVF/Intra-cytoplasmic sperm injection (ICSI) procedure and cfDNA concentration was quantified by ALU-quantitative PCR. We found that cfDNA level was significantly higher in FF samples from patients with ovarian reserve disorders (low functional ovarian reserve or polycystic ovary syndrome) than from patients with normal ovarian reserve (2.7 ± 2.7 ng/µl versus 1.7 ± 2.3 ng/µl, respectively, p = 0.03). Likewise, FF cfDNA levels were significant more elevated in women who received long ovarian stimulation (> 10 days) or high total dose of gonadotropins (≥ 3000 IU/l) than in women who received short stimulation duration (7-10 days) or total dose of gonadotropins < 3000 IU/l (2.4 ± 2.8 ng/µl versus 1.5 ± 1.9 ng/µl, p = 0.008; 2.2 ± 2.3 ng/µl versus 1.5 ± 2.1 ng/µl, p = 0.01, respectively). Finally, FF cfDNA level was an independent and significant predictive factor for pregnancy outcome (adjusted odds ratio = 0.69 [0.5; 0.96], p = 0.03). In multivariate analysis, the Receiving Operator Curve (ROC) analysis showed that the performance of FF cfDNA in predicting clinical pregnancy reached 0.73 [0.66-0.87] with 88% specificity and 60% sensitivity. CfDNA might constitute a promising biomarker of follicular micro-environment quality which could be used to predict IVF prognosis and to enhance female infertility management.