Factors inducing decreased oocyte maturation rate: a retrospective analysis of 20,939 ICSI cycles

To rescue or not to rescue immature oocytes: prospects and challenges

In vitro maturation (IVM) of immature oocytes has been explored for research and clinical purposes since the dawn of assisted reproductive technologies. Oocyte maturation is a highly specific process, on the basis of complex mutual relationships between the germ and somatic cell compartments. The complexity of this relationship has made the quest for achieving oocyte maturation in vitro arduous. In its classical form, in which intact cumulus-enclosed oocytes are collected after very mild or no ovarian stimulation, oocyte IVM is nonexperimental and has been proposed as a more friendly treatment for patients with polycystic ovary or polycystic ovary syndrome. By contrast, rescue IVM (r-IVM), which is the maturation in vitro of immature oocytes collected in standard ovarian stimulation cycles, is an experimental procedure, proposed to mitigate the impact of low oocyte maturation rates in certain patients. Achieving effective r-IVM has turned out to be an even more daunting task because oocytes are cultured only after cumulus cell removal and, therefore, without the crucial somatic metabolic and regulative support. Immature oocyte arrested at the germinal vesicle or metaphase I stage require different management for their maturation in vitro and exhibit different developmental and chromosomal competence. Therefore, their possible use for treatment suggests a dedicated approach. Overall, r-IVM has limited clinical efficacy due to suboptimal maturation and developmental competence of immature oocytes. This raises a cost/benefit question: that is, the definition of appropriate clinical indications. Rescue IVM is probably irrelevant to treatment cycles in which the absolute number of mature oocytes is high. Conversely, specific poor prognosis cases, involving low maturation rates, low oocyte yield, and/or low oocyte quality, could benefit from the contribution of even a single embryo generated from an in vitro matured oocyte. Future progress in this field will depend on our ability to mimic in vitro the support provided by cumulus cells to oocyte nuclear and cytoplasmic maturation.

Oocyte maturation defect in women undergoing IVF: contributing factors and effects on mature sibling oocyte outcomes

PURPOSE

This study aimed to identify demographic and clinical factors associated with low maturation rates and to investigate if the rate of immature oocytes impacts the outcomes of mature sibling oocytes.

METHODS

Women undergoing their first IVF-ICSI cycle between 2018 and 2022 at a fertility clinic were included. Cycles were classified into five groups according to the proportion of Metaphase II stage oocytes (MII): Null (0% MII, n = 46), Poor (1-25% MII, n = 44), Low (26-50% MII, n = 453), Acceptable (51-75% MII, n = 1641), and Optimal (76-100% MII, n = 2642). Demographic characteristics and clinical outcomes were compared between the five groups. In patients with a Null/Poor maturation rate, subsequent cycle outcomes were also evaluated.

RESULTS

A total of 4826 cycles were included in the study; 69,909 oocytes were recovered, and 53,065 were MIIs (75.9%). The Null group was older, had lower levels of anti-Müllerian hormone (AMH), needed more gonadotropins and days of stimulation, had higher follicle stimulating hormone (FSH) levels on day 3, and had less follicles > 15 mm on the day of trigger. When the outcomes of mature oocytes were compared, fertilization, usable blastocyst, aneuploidy, and life birth rates were comparable among groups. A binary logistic regression model using number of oocytes, paternal age, and trigger type with live birth rate endpoint found no differences between the categories and the base line Poor category. When patients whose maturation rate was Null/Poor, 42 (47.0%) carried out a second cycle; the maturation rate increased (56.9 ± 31.5 vs. 11.6 ± 11.2%, P < 0.0001).

CONCLUSION

Our data suggest that poor responders are more likely to have low rates of oocyte maturation. The proportion of immature oocytes does not impact the outcomes of mature sibling oocytes. In patients with Null/Poor maturation in their first cycle, the subsequent cycle is often associated with improved maturation rates.

Individualized dosing of rec-FSH for ovarian stimulation in women with PCOS reduces asynchronous follicle growth

PURPOSE

We aimed to evaluate if ovarian stimulation with individualized dosing of recombinant follicle-stimulating hormone (rec-FSH) with follitropin delta compared with standard gonadotropin dosing reduce occurrence of follicular asynchrony in women with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF).

METHODS

Matched case-control study analyzed occurrence of follicular growth asynchrony during ovarian stimulation and IVF outcomes in women with PCOS. Follicular growth was considered to be asynchronous when one or two leading follicles were at least 4 mm larger in diameter than the rest of the cohort on day 5 and 9 of stimulation. Analysis encompassed 44 women stimulated with individualized rec-FSH dosing, and 88 women treated with standard dosing. The patients were matched in terms of age, Anti-Müllerian hormone levels and body weight.

RESULTS

Early and late follicular asynchrony were present less frequently in individualized dosing compared to standard dosing group (4.5% vs 17%, p = 0.04 and 2.3% vs 37.5%, p < 0.001, on stimulation day 5 and 9, respectively). Multivariate logistic regression on follicular asynchrony revealed that individualized dosing significantly decreases the occurrence and chances for late follicular asynchrony (Odds Ratio 0.28, p < 0.001). Shorter duration of stimulation (9.6 vs 10.4 days, p = 0.001), lower total gonadotropin dose (1118 vs 1940 IU, p < 0.001), higher number of metaphase II oocytes (7.1 + 4.3 vs 5.4 ± 3.0, p = 0.001), good quality embryos (3.8 vs 2.0, p < 0.001), and implantation rates (31.0 vs 23.4, p = 0.04) were observed in the individualized dosing group.

CONCLUSION

Individualized rec-FSH dosing reduces asynchronous follicular growth and improves ovarian stimulation efficiency in women with PCOS undergoing IVF.

The impact of oocyte central granularity on ICSI practice: developmental competence of dysmorphic and morphologically normal companion oocytes

PURPOSE

To assess the effects of oocyte central granularity and its underlying endocrine environment on developmental competence of dysmorphic and morphologically normal oocytes.

METHODS

Retrospective cohort study including 1,082 patients undergoing autologous ICSI cycles. Of these, 211 patients provided 602 oocytes with central granularity (CG) and 427 morphologically normal cycle companion oocytes (NCG). The remaining 871 patients provided only morphologically normal oocytes in cycles not yielding dysmorphic oocytes (N). Patient profile associated with CG was characterized, and fertilization rates, early morphokinetics and live birth rates were compared between N, CG and NCG groups. Patient characteristics associated with implantation and delivery performance of CG-derived embryos were assessed.

RESULTS

CG was associated with higher maternal age, basal FSH concentrations and total FSH dose, but with lower circulating AMH (p ≤ 0.035). Fertilization rates were reduced and early morphokinetic parameters were delayed in CG (p < 0.025) and NCG (p < 0.05) groups as compared to the N group. Embryos derived from CG oocytes achieved a markedly lower live birth rate (14.9%) as compared to those derived from NCG (36.8%; p = 0.03) and N oocytes (29.8%; p = 0.002). The negative relationship between CG and live birth was confirmed by a multivariate analysis controlling for potential confounders (OR:2.59, IC:1.27-5.31; P = 0.009). Implantation and delivery rates following transfers of CG-derived embryos were inversely associated with maternal age.

CONCLUSION

CG oocytes, but not their morphologically normal cycle companions, have severely compromised developmental competence. Maternal age should be a key parameter in deciding whether or not to utilize CG oocytes in ICSI cycles.

Use of Triggers on in vitro Fertilization and Evaluation of Risk Factors for Sub-Optimal Maturation Rate

OBJECTIVE

 To compare the oocyte maturation rate in the treatment of in vitro fertilization (IVF) in terms of the use of human chorionic gonadotropin (hCG), agonist gonadotropin-releasing hormone (GnRH) and dual trigger and to evaluate the associated risk factors for sub-optimal maturation rates.

METHODS

 A retrospective cohort study with 856 women who underwent IVF. They performed oocyte retrieval and were classified into 3 groups (1 - hCG, 2 - GnRH agonist, 3 - dual trigger). The primary outcome was maturation rate per trigger, and the secondary outcomes were the pregnancy rate per oocyte retrieval and the correlations between low maturation rate as well as the clinical and treatment characteristics of women.

RESULTS

 The maturation rate was 77% in group 1; 76% in group 2, and 83% in group 3 (p = 0.003). Group 2 showed women with better ovarian reserve, greater number of oocytes collected, and more mature oocytes and embryos compared with the other groups (p < 0.001). The cumulative clinical pregnancy rate was no different between the groups (p = 0.755). Low ovarian reserve and low doses of follicle-stimulating hormone (FSH) administered during the stimulus were associated with a higher chance of null maturation rate.

CONCLUSION

 The oocyte maturation rates and IVF results were similar in all groups. Low ovarian reserve is associated with the worst treatment results.

Oocyte stimulation parameters influence the number and proportion of mature oocytes retrieved in assisted reproductive technology cycles

PURPOSE

Whether differences in stimulation parameters alter the number and proportion of MII oocytes retrieved.

METHODS

Records of 2546 patients were examined, looking at age, day 2/3 follicle-stimulating hormone (FSH) and estradiol (E2) levels, total dose of gonadotropins administered (including FSH and human menopausal gonadotropin [hMG]), fraction of hMG administered, number of days of treatment with gonadotropins, and the dose of gonadotropins administered per day. We segregated the patients into 3 different classes depending on the trigger method used and 2 groups based on egg freeze vs. ICSI. Multiple regression methods were used to examine associations between stimulation parameters and the total number of eggs, number of immature oocytes (Poisson regression), and the fraction of retrieved oocytes that were immature (Logistic regression).

RESULTS

After adjustments for different triggers and egg freeze versus ICSI, both the #immature oocytes and the immature fraction of oocytes were associated with the total gonadotropin dose (inversely) and the gonadotropin dose/day (positively). Other parameters were associated with the number of immature oocytes but were also associated with the number of oocytes retrieved.

CONCLUSIONS

Stimulations using less total gonadotropin and more gonadotropin per day were associated with more immaturity. The type of trigger method used for final maturation was associated with immaturity but was believed to be predominantly due to trigger assignment to patients based on response. The association between use of ICSI and less immaturity was believed to be due to additional time for maturation in the ICSI group.

In vitro rescue immature oocytes - a literature review

Immature oocytes retrieved from in vitro fertilization (IVF) and clinical in vitro maturation (IVM) is a common problem, especially in patients with advanced age, poor ovarian response (POR), or polycystic ovary syndrome (PCOS). Considering there is no common name to describe this group of oocytes, we suggest naming all of immature oocytes retrieved from IVF and clinical IVM cycles as 'Medical Unusable Oocytes' (MUO) as none of them will be used for subsequent treatment and will eventually be discarded. Scientists attempt to improve the clinical utilization rate of MUO instead of discarding them. Rescue IVM and mitochondria supplementation may be available approaches to mature MUO. We propose a specific definition of rescue IVM, namely the cultivation and maturation of immature oocytes in vitro collected from IVF cycles with human chorionic gonadotropin (hCG) trigger. Rescue IVM is usually mixed up with clinical IVM. Clarification of the differences between rescue IVM and clinical IVM is necessary. This manuscript aims to clarify the rather confusing IVM procedures and review existing methods of improving rescue IVM, currently available information on the success rate, and explore the future possibility of rescue IVM serving as a promising tool in reproductive medicine.

No impact of treated hyperprolactinemia on cumulative live birth rate and perinatal outcomes in in vitro fertilization-embryo transfer

AIM

To investigate whether treated hyperprolactinemia has an impact on pregnancy outcomes in in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET).

METHODS

A retrospective cohort study was conducted on 535 women who underwent IVF/ICSI-ET between January 2012 and December 2016, of which 123 had treated hyperprolactinemia (case group), 369 were matched controls. Besides, 43 remained hyperprolactinemic after treatment consisted of abnormal group. Cumulative live birth rate (CLBR) after one oocyte retrieval cycle was taken as the primary outcome. A time-to-event analysis using Fine and Gray's test was used to compare CLBR between case and control groups.

RESULTS

The median prolactin level was 80.00 ng/mL before dopamine agonist treatment in case group, and it reduced to 14.80 ng/mL after the treatment, similar to the level of control group (15.17 ng/mL, P = 0.316). No significant differences in baseline characteristics were found between case and control groups. The CLBR after one oocyte retrieval cycle were 69.1% (85/123) and 66.4% (245/369) in the case group and control group, respectively (P = 0.580). No significant differences were found between case and control groups in perinatal outcomes. Pregnancy and perinatal outcomes of abnormal group were similar to those of case and control groups.

CONCLUSION

Impact of treated hyperprolactinemia on CLBR and perinatal outcomes in IVF-ET was not evident.