Involvement of CATSPER 2 mutation in a familial context of unexplained infertility and fertilization failure associated with hearing loss: a case report.

Objective: To explore the functional implications of a homozygous CATSPER 2 (cation channel for sperm) deletion within the acrosome reaction pathway during fertilization in 2 brothers, who have unexplained infertility and hearing loss. Design: Case report. Patients: Two twin brothers aged 30 years with hearing loss and unexplained infertility. Exposure or Intervention: Molecular genetic diagnosis of deafness. Evaluation of the acrosome reaction and calcium mobilization assays after induction by progesterone and ionomycin on spermatozoa of the CATSPER 2-mutated patient and on fertile controls. Main Outcome Measures: Fertilization rate during conventional in vitro fertilization. Molecular genetic test. Percentage of acrosome-reacted spermatozoa with peanut agglutinin lectin staining. Recording of progesterone and ionomycin-induced intracellular calcium signals with a fluorescent probe. Results: Mr. S and his brother have normal, conventional sperm parameters. Both brothers have had repeated intrauterine insemination failures and one fertilization failure after conventional in vitro fertilization. Mr. S obtained 2 healthy babies after intracytoplasmic sperm injection. Genetic analysis found a homozygote deletion of the STRC (stereocilin) gene (NM 153700: c.1-? 5328+?del) that removes the CATSPER 2 gene. Mutation of the STRC gene is known to be associated with hearing loss. Sperm functional tests revealed an inability of progesterone to activate intracellular calcium signaling and to induce acrosome reaction. Conclusion: We demonstrate the absence of a calcium signal and acrosome reaction after progesterone in our patient with a CATSPER 2 mutation. We emphasize the importance of the male medical interview and of the genetic investigation of hearing loss. We show that in vitro fertilization-intracytoplasmic sperm injection is necessary, even where normal sperm parameters are present.

How and when to measure pH in IVF culture media: validation of a portable blood gas analyzer in two IVF culture dishes for time lapse and conventional incubators.

PURPOSE: Maintaining a stable pH at optimal level in human embryo culture media is crucial for embryo development but poses a challenge for all IVF laboratories. We validate analytically reliable conditions for pH measurement that are as close as possible to the embryo microenvironment during IVF. METHODS: This was a multicentric study. A Siemens EPOC portable blood gas analyzer was used. The analytical validation was carried out under the culture medium (Global Total HSA®) conditions of use (microdroplets, under oil overlay, in a IVF incubator with (EmbryoScope®) or without a time lapse system (K system G210+®) and using IVF dishes. The validation included repeatability ("within-run" precision), total precision (between-day precision), trueness based on inter-laboratory comparison, inaccuracy based on external quality assessment and comparison to the reference technique. We also assessed the pre-analytical medium incubation time required to obtain a target value. RESULTS: A measurement after an incubation period of 24 to 48 h is more representative of the pH to which the embryo will be exposed throughout the culture. The "within-run" and "between-day" precision show very low coefficients of variation (CV%): 0.17 to 0.22% and 0.13 to 0.34%, respectively, with IVF culture media. Trueness (% bias) range from - 0.07 to - 0.03%. We demonstrate good correlation between EPOC and reference pH electrode with an overestimation of 0.03 pH units of EPOC. CONCLUSION: Our method demonstrates good analytical performance for IVF laboratories wishing to implement a robust quality assurance system to monitor pH in embryo culture media. Compliance with stringent pre-analytical and analytical conditions is essential.

Multigenerational Effects of a Complex Human-Relevant Exposure during Folliculogenesis and Preimplantation Embryo Development: The FEDEXPO Study.

Animal toxicological studies often fail to mimic the complexity of the human exposome, associating low doses, combined molecules and long-term exposure. Since the reproductive potential of a woman begins in the fetal ovary, the literature regarding the disruption of its reproductive health by environmental toxicants remains limited. Studies draw attention to follicle development, a major determinant for the quality of the oocyte, and the preimplantation embryo, as both of them are targets for epigenetic reprogramming. The "Folliculogenesis and Embryo Development EXPOsure to a mixture of toxicants: evaluation in the rabbit model" (FEDEXPO) project emerged from consideration of these limitations and aims to evaluate in the rabbit model the impacts of an exposure to a mixture of known and suspected endocrine disrupting chemicals (EDCs) during two specific windows, including folliculogenesis and preimplantation embryo development. The mixture combines eight environmental toxicants, namely perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), ß-hexachlorocyclohexane (ß-HCH), 2,2'4,4'-tetrabromodiphenyl ether (BDE-47), di(2-ethylhexyl) phthalate (DEHP) and bisphenol S (BPS), at relevant exposure levels for reproductive-aged women based on biomonitoring data. The project will be organized in order to assess the consequences of this exposure on the ovarian function of the directly exposed F0 females and monitor the development and health of the F1 offspring from the preimplantation stage. Emphasis will be made on the reproductive health of the offspring. Lastly, this multigenerational study will also tackle potential mechanisms for the inheritance of health disruption via the oocyte or the preimplantation embryo.

International cooperation and the challenge of internet accessibility in Caribbean territories: example of a collaborative platform between the University Hospital of Martinique and Ramón González Coro Hospital in Cuba, through the French PRPH-3 program.

BACKGROUND: Martinique shares with the other Caribbean countries specific public health issues, particularly in the diagnostic and therapeutic management of cancer patients. Mutualization of human and material resources by promoting cooperation is the most appropriate response to the challenges of the health systems of the Caribbean territories. Through the French PRPH-3 program, we propose to set up a collaborative digital platform adapted to the specificities of the Caribbean to strengthen professional links and skills in oncofertility and oncosexology and reduce inequalities in access to reproductive and sexual health care for cancer patients. METHODS: Within the context of this program, we have developed of an open-source platform based on a Learning Content Management System (LCMS), with an operating system developed by UNFM for low speed internet. LO libraries have been created and interaction between trainers and learners were done in asynchronous mode. This training management platform is based on: a TCC learning system (Training, Coaching, Communities); a web-hosting with pedagogical engineering appropriate to low bandwidth; a reporting system and a responsibility for processing. RESULTS: We have carried out a flexible, multilingual and accessible digital learning strategy functionality called e-MCPPO according to low-speed internet ecosystem. In close connection with the e-learning strategy we conceived (i) a multidisciplinary team; (ii) an appropriate training program for expert health professionals and (iii) a responsive design. DISCUSSION AND CONCLUSION: This low-speed web-based infrastructure allows communities of experts to cooperate in creating, validating, publishing and managing academic learning content. The self-learning modules provide the digital layer for each learner to extend their skills. Learners, as well as trainers, would gradually take ownership of this platform and encourage its promotion. Innovation in this context is both technological (low-speed Internet broadcasting, free interactive software) and organizational (moderating educational resources). This collaborative digital platform is unique in its form and content. This challenge could contribute to the digital transformation of the Caribbean ecosystem for capacity building in this specifics topics.

Is in vitro maturation of oocytes retrieved ex vivo from ovarian tissue an effective fertility preservation technique in the presence of organic ovarian cysts?

OBJECTIVE(S): In vitro maturation (IVM) of oocytes retrieved ex vivo from ovarian tissue (OTO-IVM) could be an additional source of mature oocytes with the potential to optimise medical fertility preservation (FP) after oophorectomy. It is often undertaken at the same time as the ovarian tissue cryopreservation (OTC). In the presence of an organic ovarian cyst, OTO-IVM could prove to be the only technique available to permit FP since ovarian stimulation, transvaginal ovarian needle puncture or future ovarian tissue graft are contraindicated. However, the presence of an organic cyst could alter follicular growth and the number of retrievd oocytes. Our study aims to assess the efficiency of OTO-IVM in such situations. STUDY DESIGN: Retrospective, observational study involving 20 female patients with FP by OTO-IVM between May 2017 and November 2021 at the University Hospital of Toulouse. Oocytes retrieved "ex vivo" were transferred to an IVM medium with HP-hMG, LH and HSA and then vitrified after 24 to 48 h of IVM. Data analysis was performed on the total population and comparatively between patients who had or did not have an organic ovarian cyst. RESULTS: The indications included 15 oncologic and 5 non-oncologic indications. Ten had an organic ovarian cyst on the retrieved ovary. The number of retrieved oocytes was 17.4+/-12.0 in the absence of cyst vs 4.1+/-6.3 in the presence (p = 0.003). The number of vitrified mature oocytes was 5.8+/-5.3 in the absence vs 1.1+/-2.2 (median = 0) in the presence of a cyst (p = 0.03). Ninety percent of the patients with an organic cyst had less than two vitrified mature oocytes. The mean maturation rate was 34%, not significantly different between the two groups. We found a correlation between serum AMH level and the number of mature oocytes: ρ:0.47 CI95 = [0.02; 0.76]; p = 0.04. CONCLUSION(S): OTO-IVM is an additional source of mature oocytes to optimise FP after oophorectomy. However, in the presence of an organic ovarian cyst on the retrieved ovary, the exocrine, paracrine and endocrine functions of the ovary are impaired. As such, the number of immature oocytes obtained is highly impacted and appears to be insufficient to be able to propose systematically this technique in such situations.

Pre- and Postnatal Dietary Exposure to a Pesticide Cocktail Disrupts Ovarian Functions in 8-Week-Old Female Mice.

Female infertility has a multifactorial origin, and exposure to contaminants, including pesticides, with endocrine-disrupting properties is considered to be involved in this reproductive disorder, especially when it occurs during early life. Pesticides are present in various facets of the environment, and consumers are exposed to a combination of multiple pesticide residues through food intake. The consequences of such exposure with respect to female fertility are not well known. Therefore, we aimed to assess the impact of pre- and postnatal dietary exposure to a pesticide mixture on folliculogenesis, a crucial process in female reproduction. Mice were exposed to the acceptable daily intake levels of six pesticides in a mixture (boscalid, captan, chlorpyrifos, thiacloprid, thiophanate and ziram) from foetal development until 8 weeks old. Female offspring presented with decreased body weight at weaning, which was maintained at 8 weeks old. This was accompanied by an abnormal ovarian ultrastructure, a drastic decrease in the number of corpora lutea and progesterone levels and an increase in ovary cell proliferation. In conclusion, this study shows that this pesticide mixture that can be commonly found in fruits in Europe, causing endocrine disruption in female mice with pre- and postnatal exposure by disturbing folliculogenesis, mainly in the luteinisation process.

Semi-automated versus manual embryo vitrification: inter-operator variability, time-saving, and clinical outcomes.

PURPOSE: Does semi-automated vitrification have lower inter-operator variability and better clinical outcomes than manual vitrification? METHODS: Retrospective analyses of 282 patients whose embryos had been cryopreserved, manually with Irvine®-CBS® (MV) or semi-automatically vitrified with the GAVI® method (AV) (from November 2017 to September 2020). Both techniques were performed during the same period by 5 operators. Inter-operator variability was statistically analyzed between operators who performed the vitrification and those who performed the warming process to compare the intact survival rate (% embryos with 100% intact blastomeres) and the positive survival rate (at least 50% intact blastomeres). Additionally, the complete vitrification time was assessed for the 2 techniques according to the number of vitrified embryos. RESULTS: Manual vitrification involved warming 338 embryos in 266 cycles for 181 couples compared to 212 embryos in 162 AV cycles for 101 patients. The positive survival rate was higher (p < 0.05) after MV (96%; 323/338) than after AV (90%; 191/212). The intact survival rate (86 vs 84%) and the clinical pregnancy rate (27 vs 22%) were not significantly different between MV and AV. Regarding the inter-operator variability, no significant difference in positive and intact survival rate was evident between the 5 technicians, neither by vitrification nor by warming steps with MV and AV. Concerning time-saving, the MV technique proved to be quicker than AV (minus 11 ± 9 min). CONCLUSIONS: Manual vitrification exhibited favorable total survival rates and was more time efficient, while both MV and AV cooling and warming treatments showed little operator variability.

Need for choosing the ideal pH value for IVF culture media.

PURPOSE: Monitoring the pH of IVF culture media is a good practice, but the required pH levels have been "arbitrarily" set. Assisted reproductive technology centers around the world are spending time and money on pH monitoring without any consensus to date. The objective of this narrative review was to evaluate the importance of pH monitoring during IVF, discover how the oocyte and embryo regulate their intracellular pH and try to determine the optimal pH to be applied. METHODS: A narrative literature review was performed on publications in the PubMed database reporting on the impact of pH on cellular function, oocyte and embryo development, IVF outcomes and pathophysiology, or on physiological pH in the female reproductive tract. RESULTS: Intracellular pH regulates many cellular processes such as meiotic spindle stability of the oocyte, cell division and differentiation, embryo enzymatic activities, and blastocoel formation. The internal pH of the human embryo is maintained by regulatory mechanisms (mainly Na+/H+ and HCO3-/Cl- exchangers) that can be exceeded, particularly in the oocyte and early-stage embryos. The opinion that the optimal pH for embryo culture is physiological pH is not correct since several physicochemical parameters specific to IVF culture conditions (temperature, medium composition, duration of culture, or implication of CO2) can modify the intracellular pH of the embryo and change its needs and adaptability. CONCLUSIONS: Because correct and stable extracellular pH is essential to embryo health and development, monitoring pH is imperative. However, there is a lack of clinical data on choosing the ideal pH for human IVF culture media.

Potential chances for natural fertility influence results of intrauterine inseminations.

OBJECTIVE: Intra-uterine insemination (IUI) is widely used for different indications. The aim of the present study was to evaluate the efficiency of intra-uterine insemination as a function of indication and origin of the inseminated spermatozoa. STUDY DESIGN: The retrospective study involved 827 first attempts of IUI in 827 couples between January 2011 and July 2017 in the Toulouse university hospital. Of these, 642 used fresh sperm from the husband, 40 frozen sperm from the husband and 145 frozen sperm from donors. The measured outcome parameter was live birth rate per attempt. RESULTS: When comparing couples lacking functional gametes (due to male or female causes), to couples who could potentially conceive spontaneously, i.e. subfertile, the latter were found to have a significantly lower live birth rate (18% vs 26%; P < 0.05). Even when adjusted for demographic parameters, which differed significantly between the 2 groups (female age, percentage of women suffering from primary infertility, BMI, number of inseminated motile spermatozoa and stimulation duration), this difference remained statistically significant (OR = 0.639 [0.425-0.961]; P = 0.0316). CONCLUSION: When compared to couples lacking functional gametes, subfertile couples have poor IUI outcomes, suggesting a hidden cause of infertility, despite no apparent differences in ovarian reserve, tubal potency, results of ovarian stimulation and normal conventional sperm parameters. Further studies are required to better characterise and identify this subgroup of women with poor IUI outcomes.

Age-specific anti-Mullerian hormone (AMH) levels poorly affects cumulative live birth rate after intra-uterine insemination.

OBJECTIVE: To evaluate the impact of age-specific anti-Mullerian (AMH) levels on the cumulative live birth rate after 4 intra uterine inseminations (IUI). STUDY DESIGN: The retrospective study study involved 509 couples who underwent their first IUI between January 2011 and July 2017 in the Toulouse University Hospital. All IUI were performed after an ovarian stimulation combining recombinant FSH and GnRH antagonist. The main measure outcome was the cumulative live birth rate (LBR) defined as the number of deliveries with at least one live birth resulting from a maximum of 4 IUI attempts. RESULTS: When compared to normal or high levels, low age-specific AMH (<25th of the AMH in each age group) was associated to a non-significant lower live birth rate (31%, 38% and 42% respectively for low, normal and high age-specific groups; P = 0.170) and non-significant higher miscarriage rate (26%; 19% and 14% respectively for low, normal and high age-specific groups; P = 0.209). However, it must be pointed out that in low age-specific AMH the initial FSH doses used for stimulation were higher than in the other groups. CONCLUSION: This study shows that the age-specific levels of AMH have only a slight effect on IUI outcome when adapting the stimulation protocols to their level.

Association between progesterone to number of mature oocytes index and live birth in GnRH antagonist protocols.

RESEARCH QUESTION: What is the association between blood progesterone level alone, progesterone to mature oocytes index (PMOI) and IVF outcomes? DESIGN: Clinical data from 960 couples undergoing their first fresh embryo transfer after an intracytoplasmic sperm injection attempt carried out between September 2012 and July 2017 were analysed. All patients underwent ovarian stimulation combining recombinant FSH and gonadotrophin releasing hormone antagonist. Progesterone was measured on the day on which ovulation was triggered. The PMOI was divided into four groups based on 25th, 50th and 75th percentiles, and live birth and implantation rates were compared between the groups. RESULTS: A negative association was found between PMOI levels, live birth and implantation rates. When adjusting for age, ovarian stimulation index (OSI) and number of embryos transferred, the PMOI remained negatively correlated to live birth rate (LBR) (OR = 0.147 [0.031 to 0.701]; P = 0.0161), whereas total blood progesterone was no longer evident. Moreover, the LBR (18.5% versus 28.4%; P < 0.01) and implantation rate (12.4% versus 21.0%; P < 0.01) were significantly decreased only when PMOI was 0.167 ng/ml or greater, irrespective of progesterone concentration (< or ≥1.08 ng/ml). The opposite was not true, however. Similar PMOIs were recorded in the same patient from one attempt to the next, and were partially linked to basal FSH, anti-Müllerian hormone, antral follicle count and OSI. CONCLUSIONS: PMOI seems to be more predictive than total progesterone level of IVF outcome and reflects the ability of embryos to develop as it is linked to the implantation rate.

Impact of estradiol and progesterone levels during the late follicular stage on the outcome of GnRH antagonist protocols.

The study aimed to assess the impacts and the targets of progesterone (P4) and estradiol (E2) levels on IVF outcomes in GnRH antagonist protocols. The study was retrospective and concerned patients for their first fresh embryo transfers, after stimulation by a recombinant FSH (rFSH)-GnRH antagonist protocol, between September 2012 and July 2017 in the Toulouse University Hospital. Multivariable analysis, taking into account female age and the ovarian stimulation index, showed that E2 levels had no impact on IVF outcomes, while high P4 levels (>1.10 ng/mL) were associated to low pregnancy rate. The P4 concentrations were significantly negatively correlated to the percentage of top embryos and to the implantation rate. Therefore, the deleterious effect of high levels P4 could to act mainly by impairing embryo quality, which questions the place of the freeze-all strategy in these cases.

Anti-sperm antibodies detection by a modified MAR test: Towards a better definition of its indications.

RESEARCH QUESTION: Anti-sperm antibodies (ASA) have been shown to reduce male fertility but consensus about the precise situations in which tests should be carried out are lacking. In infertility investigations, should the mixed antiglobulin reaction (MAR) test be a first-line test? Should it be carried out systematically before assisted reproductive technology (ART)? What are the risk factors for ASA? DESIGN: All infertile patients (n = 1364) were tested with SpermMar (modified MAR test) between July 2013 and June 2017. Intra-patient variability of the MAR test was also assesed by comparing two tests within the same year in selected patients (n = 101). RESULTS: The main factor that influenced the percentage of ASA was the presence or absence of sperm agglutination. In the presence of agglutinations, 27 out of 72 (37.5%) patients were positive for ASA compared with 33 out of 1292 (2.6%) in the absence of agglutinations (P < 0.0001). When one risk factor was present (spontaneous sperm agglutination, history of scrotal trauma or inguinal surgery), 33 out of 179 (18.44%) tests were positive for ASA (≥50% coated spermatozoa), whereas only 27 out of 1242 (2.2%) were positive when no risk factor was present (P < 0.0001). CONCLUSIONS: ASA detection should not be systematically recommended in investigations of fertility status and before ART but reserved for when sperm agglutination is found during conventional sperm examination, or if the patient has a history of scrotal trauma or has undergone inguinal surgery.

Mother's age at menopause but not own age at menarche has an impact on ovarian reserve.

To detect clinical parameters impacting ovarian reserve, data were analyzed from 573 patients who had an anti-Müllerian hormone (AMH) measurement for infertility treatment. No impact was found on the age at menarche but a significant diminished ovarian reserve was observed when a patient's mother was menopausal before age 50. These data suggest that ovarian reserve must be monitored in such patients to offer them fertility preservation when at risk of premature ovarian insufficiency (POI).

Establishment and validation of a score to predict ovarian response to stimulation in IVF.

This study aimed to integrate clinical and biological parameters in a score able to predict ovarian response to stimulation for IVF in gonadotrophin-releasing hormone (GnRH) antagonist protocols. A progressive discriminant analysis to establish a score including the main clinical and biological parameters predicting ovarian response was performed by retrospectively analysing data from the first ovarian stimulation cycle of 494 patients. The score was validated in a prospectively enrolled, independent set of 257 patients undergoing their first ovarian stimulation cycle. All ovarian stimulations were performed using a combination of GnRH antagonist and recombinant FSH. Ovarian response was assessed through ovarian sensitivity index (OSI). Parameters from the patients' database were classified according to correlation with OSI: the progressive discriminant analysis resulted in the following calculation: score = 0.192 - (0.004 × FSH (IU/l)) + (0.012 × LH:FSH ratio) + (0.002 × AMH (ng/ml)) - (0.002 × BMI (kg/m2)) + (0.001 × AFC) - (0.002 × age (years)). This score was significantly correlated with OSI in the retrospective (r = 0.599; P < 0.0001) and prospective (r = 0.584; P < 0.0001) studies. In conclusion, the score including clinical and biological parameters could explain 60% of the variance in ovarian response to stimulation.

Does air pollution play a role in infertility?: a systematic review.

BACKGROUND: Air pollution is involved in many pathologies. These pollutants act through several mechanisms that can affect numerous physiological functions, including reproduction: as endocrine disruptors or reactive oxygen species inducers, and through the formation of DNA adducts and/or epigenetic modifications. We conducted a systematic review of the published literature on the impact of air pollution on reproductive function. Eligible studies were selected from an electronic literature search from the PUBMED database from January 2000 to February 2016 and associated references in published studies. Search terms included (1) ovary or follicle or oocyte or testis or testicular or sperm or spermatozoa or fertility or infertility and (2) air quality or O3 or NO2 or PM2.5 or diesel or SO2 or traffic or PM10 or air pollution or air pollutants. The literature search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We have included the human and animal studies corresponding to the search terms and published in English. We have excluded articles whose results did not concern fertility or gamete function and those focused on cancer or allergy. We have also excluded genetic, auto-immune or iatrogenic causes of reduced reproduction function from our analysis. Finally, we have excluded animal data that does not concern mammals and studies based on results from in vitro culture. Data have been grouped according to the studied pollutants in order to synthetize their impact on fertility and the molecular pathways involved. CONCLUSION: Both animal and human epidemiological studies support the idea that air pollutants cause defects during gametogenesis leading to a drop in reproductive capacities in exposed populations. Air quality has an impact on overall health as well as on the reproductive function, so increased awareness of environmental protection issues is needed among the general public and the authorities.

Effect of unilateral tubal abnormalities on the results of intrauterine inseminations.

A total of 101 patients with one normal tube were compared with 117 patients with two normal tubes to assess the effect of unilateral tubal abnormalities on the results of intrauterine inseminations. The clinical pregnancy and live birth rates seemed to reduce by one-half in almost all types of abnormality, suggesting that these patients should be preferentially treated with IVF.

Ovarian Mucinous Cystadenoma After Ovarian Graft.

BACKGROUND: Freezing strips of ovarian cortex before chemotherapy followed by transplantation is an experimental method to preserve fertility for reproductive-aged women with cancer. We report a case of a cancer patient who developed a mucinous cystadenoma in a grafted piece of ovarian cortex. CASE: A 32-year-old woman with a Ewing sarcoma had ovarian cryopreservation using cortical strip freezing before receiving chemotherapy. Five years later she had no ovarian function, and the strips were thawed and grafted back onto the ovary. She spontaneously became pregnant 1 year after this procedure and delivered a healthy neonate near term. During the cesarean delivery, a 5×3-cm cyst was removed from the graft. On pathologic evaluation, it was determined to be a mucinous cystadenoma. CONCLUSION: Ovarian pathology can develop in previously frozen ovarian cortex tissue after transplantation back onto the ovary. This suggests that routine gynecologic surveillance remains important for these women.

Follicular growth but absence of oocyte and cumulus maturation during ovarian stimulation in the days following surgical abortion: a case report.

This paper is a case report on the results of an ovarian stimulation performed in the days following an induced abortion. A patient had breast cancer diagnosed during an early pregnancy. She had an induced abortion and had, before chemotherapy an ovarian stimulation, using rFSH and GnRH antagonist, followed by follicular puncture for oocyte for vitrification in the view of fertility preservation. No oocyte could be obtained despite a good hormonal and ultrasonographical follicular growth. This case report suggest that ovarian stimulation must be delayed after abortion to allow the maturation of oocyte-cumulus complexes.