Prediction of spontaneous preterm birth in women with previous full dilatation cesarean delivery

BACKGROUND

A previous term (≥37 weeks' gestation), full-dilatation cesarean delivery is associated with an increased risk for a subsequent spontaneous preterm birth. The mechanism is unknown. We hypothesized that the cesarean delivery scar characteristics and scar position relative to the internal cervical os may compromise cervical function, thereby leading to shortening of the cervical length and spontaneous preterm birth.

OBJECTIVE

This study aimed to determine the relationship of cesarean delivery scar characteristics and position, assessed by transvaginal ultrasound, in pregnant women with previous full-dilatation cesarean delivery with the risk of shortening cervical length and spontaneous preterm birth.

STUDY DESIGN

This was a single-center, prospective cohort study of singleton pregnant women (14 to 24 weeks' gestation) with a previous term full-dilatation cesarean delivery who attended a high-risk preterm birth surveillance clinic (2017-2021). Women underwent transvaginal ultrasound assessment of cervical length, cesarean delivery scar distance relative to the internal cervical os, and scar niche parameters using a reproducible transvaginal ultrasound technique. Spontaneous preterm birth prophylactic interventions (vaginal cervical cerclage or vaginal progesterone) were offered for short cervical length (≤25 mm) and to women with a history of spontaneous preterm birth or late miscarriage after full-dilatation cesarean delivery. The primary outcome was spontaneous preterm birth; secondary outcomes included short cervical length and a need for prophylactic interventions. A multivariable logistic regression analysis was used to develop multiparameter models that combined cesarean delivery scar parameters, cervical length, history of full-dilatation cesarean delivery, and maternal characteristics. The predictive performance of models was examined using the area under the receiver operating characteristics curve and the detection rate at various fixed false positive rates. The optimal cutoff for cesarean delivery scar distance to best predict a short cervical length and spontaneous preterm birth was analyzed.

RESULTS

Cesarean delivery scars were visualized in 90.5% (220/243) of the included women. The spontaneous preterm birth rate was 4.1% (10/243), and 12.8% (31/243) of women developed a short cervical length. A history- (n=4) or ultrasound-indicated (n=19) cervical cerclage was performed in 23 of 243 (9.5%) women; among those, 2 (8.7%) spontaneously delivered prematurely. A multiparameter model based on absolute scar distance from the internal os best predicted spontaneous preterm birth (area under the receiver operating characteristics curve, 0.73; 95% confidence interval, 0.57-0.89; detection rate of 60% for a fixed 25% false positive rate). Models based on the relative anatomic position of the cesarean delivery scar to the internal os and the cesarean delivery scar position with niche parameters (length, depth, and width) best predicted the development of a short cervical length (area under the receiver operating characteristics curve, 0.79 [95% confidence interval, 0.71-0.87]; and 0.81 [95% confidence interval, 0.73-0.89], respectively; detection rate of 73% at a fixed 25% false positive rate). Spontaneous preterm birth was significantly more likely when the cesarean delivery scar was <5.0 mm above or below the internal os (adjusted odds ratio, 6.87; 95% confidence interval, 1.34-58; P =.035).

CONCLUSION

In pregnancies following a full-dilatation cesarean delivery, cesarean delivery scar characteristics and distance from the internal os identified women who were at risk for spontaneous preterm birth and developing short cervical length. Overall, the spontaneous preterm birth rate was low, but it was significantly increased among women with a scar located <5.0 mm above or below the internal cervical os. Shortening of cervical length was strongly associated with a low scar position. Our novel findings indicate that a low cesarean delivery scar can compromise the functional integrity of the internal cervical os, leading to cervical shortening and/or spontaneous preterm birth. Assessment of the cesarean delivery scar characteristics and position seem to have use in preterm birth clinical surveillance among women with a previous, full-dilatation cesarean delivery and could better identify women who would benefit from prophylactic interventions.

Integrated Placental Modelling of Histology with Gene Expression to Identify Functional Impact on Fetal Growth

Fetal growth restriction (FGR) is a leading cause of perinatal morbidity and mortality. Altered placental formation and functional capacity are major contributors to FGR pathogenesis. Relating placental structure to function across the placenta in healthy and FGR pregnancies remains largely unexplored but could improve understanding of placental diseases. We investigated integration of these parameters spatially in the term human placenta using predictive modelling. Systematic sampling was able to overcome heterogeneity in placental morphological and molecular features. Defects in villous development, elevated fibrosis, and reduced expression of growth and functional marker genes (IGF2, VEGA, SLC38A1, and SLC2A3) were seen in age-matched term FGR versus healthy control placentas. Characteristic histopathological changes with specific accompanying molecular signatures could be integrated through computational modelling to predict if the placenta came from a healthy or FGR pregnancy. Our findings yield new insights into the spatial relationship between placental structure and function and the etiology of FGR.

Time series radiomics for the prediction of prostate cancer progression in patients on active surveillance

Serial MRI is an essential assessment tool in prostate cancer (PCa) patients enrolled on active surveillance (AS). However, it has only moderate sensitivity for predicting histopathological tumour progression at follow-up, which is in part due to the subjective nature of its clinical reporting and variation among centres and readers. In this study, we used a long short-term memory (LSTM) recurrent neural network (RNN) to develop a time series radiomics (TSR) predictive model that analysed longitudinal changes in tumour-derived radiomic features across 297 scans from 76 AS patients, 28 with histopathological PCa progression and 48 with stable disease. Using leave-one-out cross-validation (LOOCV), we found that an LSTM-based model combining TSR and serial PSA density (AUC 0.86 [95% CI: 0.78-0.94]) significantly outperformed a model combining conventional delta-radiomics and delta-PSA density (0.75 [0.64-0.87]; p = 0.048) and achieved comparable performance to expert-performed serial MRI analysis using the Prostate Cancer Radiologic Estimation of Change in Sequential Evaluation (PRECISE) scoring system (0.84 [0.76-0.93]; p = 0.710). The proposed TSR framework, therefore, offers a feasible quantitative tool for standardising serial MRI assessment in PCa AS. It also presents a novel methodological approach to serial image analysis that can be used to support clinical decision-making in multiple scenarios, from continuous disease monitoring to treatment response evaluation. KEY POINTS: •LSTM RNN can be used to predict the outcome of PCa AS using time series changes in tumour-derived radiomic features and PSA density. •Using all available TSR features and serial PSA density yields a significantly better predictive performance compared to using just two time points within the delta-radiomics framework. •The concept of TSR can be applied to other clinical scenarios involving serial imaging, setting out a new field in AI-driven radiology research.

Serum biomarker-based early detection of pancreatic ductal adenocarcinomas with ensemble learning

BACKGROUND

Earlier detection of pancreatic ductal adenocarcinoma (PDAC) is key to improving patient outcomes, as it is mostly detected at advanced stages which are associated with poor survival. Developing non-invasive blood tests for early detection would be an important breakthrough.

METHODS

The primary objective of the work presented here is to use a dataset that is prospectively collected, to quantify a set of cancer-associated proteins and construct multi-marker models with the capacity to predict PDAC years before diagnosis. The data used is part of a nested case-control study within the UK Collaborative Trial of Ovarian Cancer Screening and is comprised of 218 samples, collected from a total of 143 post-menopausal women who were diagnosed with pancreatic cancer within 70 months after sample collection, and 249 matched non-cancer controls. We develop a stacked ensemble modelling technique to achieve robustness in predictions and, therefore, improve performance in newly collected datasets.

RESULTS

Here we show that with ensemble learning we can predict PDAC status with an AUC of 0.91 (95% CI 0.75-1.0), sensitivity of 92% (95% CI 0.54-1.0) at 90% specificity, up to 1 year prior to diagnosis, and at an AUC of 0.85 (95% CI 0.74-0.93) up to 2 years prior to diagnosis (sensitivity of 61%, 95% CI 0.17-0.83, at 90% specificity).

CONCLUSIONS

The ensemble modelling strategy explored here outperforms considerably biomarker combinations cited in the literature. Further developments in the selection of classifiers balancing performance and heterogeneity should further enhance the predictive capacity of the method.

P-479 Oocyte morphology in cancer patients undergoing fertility preservation

Study question

The aim of this study was to evaluate the influence of oncological disease on oocyte morphology in patients undergoing fertility preservation (FP) before cancer treatment.

Summary answer

Oncological disease could be a risk factor for oocyte dysmorphology, considering higher incidence of dysmorphisms in patients with hematological cancer and BRCA mutation carriers.

What is known already

The data on the effect of oncological disease and the type of cancer on ovarian stimulation outcomes are still limited.There is evidence about a higher incidence of alterations in oocyte morphology among pantients indergoing fertility preservation, most of them attribute it to the use of letrozole. However the clinical impact of cancer on the incidence of oocyte dismorphysms and the following IVF outcomes is unclear. The published studies highlight the importance of establishing the influence of such factors on the oocyte quality.

Study design, size, duration

This prospective clinical trial was conducted at the V.I. Kulakov Scientific Research Center for OG&P in Russia. Patients with cancer who had requested oocyte and/or embryo retrieval and cryopreservation prior to cancer treatment were included in the study. A total of 240 patients were selected for the study. All patients signed an informed consent form approved by the ethics committee before participating in the study.

Participants/materials, setting, methods

The patients were divided into 5 groups: group I (n = 65) included patients with breast cancer; group II (n = 35) - cervical cancer; group III (n = 48) - hematologic cancer and group IV (n = 40) - other types of cancer. Group V (n = 52) consisted of comparable patients with tubal factor of infertility. We analysed characteristics of oogenesis and embryogenesis.

We observed the features of cytoplasm, zona pellucida and the perivitelline space and polar bodies of human oocytes.

Main results and the role of chance

The mean age, BMI and AMH did not differ among groups.

The number of mature oocytes obtained was significantly lower in all groups with cancer (I-553 (68.6%), II-239 (77.4%), III-394 (76.4%) and IV-267 (71.0%)) compared to 312 (75%) in the control group (p = 0.005). As it can be seen from the data, patients with breast cancer had a large number of immature and degenerated oocytes. Moreover, the frequency of suoocyte dysmorphysms (such an increased perivitelline space (p = 0.007), an irregular zona pellucida (p &lt; 0.001)) was higher. These changes may be associated with the prescription of aromatase inhibitors to the group of patients. The presence of cytoplasmic vacuoles in the oocytes in the group of patients with hematologic cancer was also significantly higher (p &lt; 0.001).

An important step in the work was to analyze the number and quality of oocytes obtained from BRCA-positive breast cancer patients. The present study included 18 women with BRCA-positive breast cancer.

The number of degenerated oocytes and oocytes with necrotic cytoplasmic areas was significantly higher in the group of patients carrying a germinal mutation in the BRCA gene.

Limitations, reasons for caution

the findings of our study suggest that women with cancer undergoing FP achieve similar oocyte yields as women with no cancer, although those with hematological cancer and BRCA mutation carriers have more frequent changes in oocyte morphology.

Wider implications of the findings

Our findings contribute to preexisting evidence that FP should be offered to pre-menopausal women diagnosed with cancer.

Trial registration number

not applicable

P-665 Fertility in female patients treated for Hodgkin’s lymphoma

Study question

we aimed to determine factors which could possibly predict future ability to conceive in patients that are to be treated for Hodgkin's lymphoma.

Summary answer

we identified the key characteristics for high probability to achieve a spontaneous pregnancy: younger age, high ovarian reserve and GnrH-a or COC during chemotherapy.

What is known already

Hodgkin's lymphoma is considered one of the most aggressive yet successfully treatable oncological diseases. Prevalence among younger patients and highly gonadotoxic chemotherapy regimens bring up a question of fertility preservation. The issue of predicting the future fertility potential of patients who will have undergone chemotherapy treatment is unresolved to this day. Determining the influence of different factors would allow the creation of personalized fertility preservation treatment plans for each patient.

Study design, size, duration

This observational study was conducted at the V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology. It included 149 patients of reproductive age diagnosed with Hodgkin's lymphoma who had indications to chemotherapy. All of the patients signed an informed consent form prior to participation.

Participants/materials, setting, methods

The study included 149 participants with a mean age of 23 ± 6.08 years. All of the participants underwent chemotherapy either without (68.09%) or with ovarian protection (OP) (31.91%). The prevalent chemotherapeutic agents were Adriamycin, Oncovin and Bleomycin. The median number of cycles was 6 ± 2.62.

Main results and the role of chance

Out of all patients 18 had a recurrence and only one died. One patient had three recurrences but after treatment she resumed her menstrual function, achieved one spontaneous pregnancy and live birth. This patient was only 21 years old with very high antral follicular count and had a very short period between recurrences, that way her treatment was performed with continuous GnRH-a protection. Out of patients without OP, 44.8% lost their menstrual function and later had to undergo assisted reproduction treatment, including oocyte donation. Menstrual function recovery rate was higher in both groups with GnRH-a and COC - 80% and 84%, respectively – but not high enough to be statistically significant. Time to recovery was 2 ± 2.57 months, with no significant difference between groups with COC, GnRH-a or without any protection. Patients aged 30 and older had a lower menstruation recovery rate (33.33%) compared to 71.08% and 75% for those younger than 30 and 20, respectively. Two more patients were prepubescent and therefore were not included in the statistical analysis but showed normal regular menses after menarche and achieved spontaneous pregnancies.

Limitations, reasons for caution

Despite aforementioned results the quantity of factors does not let us draw compelling conclusions about their degree of influence; this way multifactorial analysis with more participants would be more preferable. A higher rate of pregnancies in OP group could also correlate with higher alertness and therefore earlier attempts to conceive.

Wider implications of the findings

our findings demonstrate the need for and possibility of predictive model development. This would provide an opportunity not only to establish fertility preservation treatment options but also help in reproductive planning for those who have completed their main treatment, taking the risk of POI into consideration.

Trial registration number

not applicable

Comparative performance of MRI-derived PRECISE scores and delta-radiomics models for the prediction of prostate cancer progression in patients on active surveillance

OBJECTIVES

To compare the performance of the PRECISE scoring system against several MRI-derived delta-radiomics models for predicting histopathological prostate cancer (PCa) progression in patients on active surveillance (AS).

METHODS

The study included AS patients with biopsy-proven PCa with a minimum follow-up of 2 years and at least one repeat targeted biopsy. Histopathological progression was defined as grade group progression from diagnostic biopsy. The control group included patients with both radiologically and histopathologically stable disease. PRECISE scores were applied prospectively by four uro-radiologists with 5-16 years' experience. T2WI- and ADC-derived delta-radiomics features were computed using baseline and latest available MRI scans, with the predictive modelling performed using the parenclitic networks (PN), least absolute shrinkage and selection operator (LASSO) logistic regression, and random forests (RF) algorithms. Standard measures of discrimination and areas under the ROC curve (AUCs) were calculated, with AUCs compared using DeLong's test.

RESULTS

The study included 64 patients (27 progressors and 37 non-progressors) with a median follow-up of 46 months. PRECISE scores had the highest specificity (94.7%) and positive predictive value (90.9%), whilst RF had the highest sensitivity (92.6%) and negative predictive value (92.6%) for predicting disease progression. The AUC for PRECISE (84.4%) was non-significantly higher than AUCs of 81.5%, 78.0%, and 80.9% for PN, LASSO regression, and RF, respectively (p = 0.64, 0.43, and 0.57, respectively). No significant differences were observed between AUCs of the three delta-radiomics models (p-value range 0.34-0.77).

CONCLUSIONS

PRECISE and delta-radiomics models achieved comparably good performance for predicting PCa progression in AS patients.

KEY POINTS

• The observed high specificity and PPV of PRECISE are complemented by the high sensitivity and NPV of delta-radiomics, suggesting a possible synergy between the two image assessment approaches. • The comparable performance of delta-radiomics to PRECISE scores applied by expert readers highlights the prospective use of the former as an objective and standardisable quantitative tool for MRI-guided AS follow-up. • The marginally superior performance of parenclitic networks compared to conventional machine learning algorithms warrants its further use in radiomics research.

A proteomic survival predictor for COVID-19 patients in intensive care

Global healthcare systems are challenged by the COVID-19 pandemic. There is a need to optimize allocation of treatment and resources in intensive care, as clinically established risk assessments such as SOFA and APACHE II scores show only limited performance for predicting the survival of severely ill COVID-19 patients. Additional tools are also needed to monitor treatment, including experimental therapies in clinical trials. Comprehensively capturing human physiology, we speculated that proteomics in combination with new data-driven analysis strategies could produce a new generation of prognostic discriminators. We studied two independent cohorts of patients with severe COVID-19 who required intensive care and invasive mechanical ventilation. SOFA score, Charlson comorbidity index, and APACHE II score showed limited performance in predicting the COVID-19 outcome. Instead, the quantification of 321 plasma protein groups at 349 timepoints in 50 critically ill patients receiving invasive mechanical ventilation revealed 14 proteins that showed trajectories different between survivors and non-survivors. A predictor trained on proteomic measurements obtained at the first time point at maximum treatment level (i.e. WHO grade 7), which was weeks before the outcome, achieved accurate classification of survivors (AUROC 0.81). We tested the established predictor on an independent validation cohort (AUROC 1.0). The majority of proteins with high relevance in the prediction model belong to the coagulation system and complement cascade. Our study demonstrates that plasma proteomics can give rise to prognostic predictors substantially outperforming current prognostic markers in intensive care.

Parenclitic and Synolytic Networks Revisited

Parenclitic networks provide a powerful and relatively new way to coerce multidimensional data into a graph form, enabling the application of graph theory to evaluate features. Different algorithms have been published for constructing parenclitic networks, leading to the question-which algorithm should be chosen? Initially, it was suggested to calculate the weight of an edge between two nodes of the network as a deviation from a linear regression, calculated for a dependence of one of these features on the other. This method works well, but not when features do not have a linear relationship. To overcome this, it was suggested to calculate edge weights as the distance from the area of most probable values by using a kernel density estimation. In these two approaches only one class (typically controls or healthy population) is used to construct a model. To take account of a second class, we have introduced synolytic networks, using a boundary between two classes on the feature-feature plane to estimate the weight of the edge between these features. Common to all these approaches is that topological indices can be used to evaluate the structure represented by the graphs. To compare these network approaches alongside more traditional machine-learning algorithms, we performed a substantial analysis using both synthetic data with a priori known structure and publicly available datasets used for the benchmarking of ML-algorithms. Such a comparison has shown that the main advantage of parenclitic and synolytic networks is their resistance to over-fitting (occurring when the number of features is greater than the number of subjects) compared to other ML approaches. Secondly, the capability to visualise data in a structured form, even when this structure is not a priori available allows for visual inspection and the application of well-established graph theory to their interpretation/application, eliminating the "black-box" nature of other ML approaches.

A time-resolved proteomic and prognostic map of COVID-19

COVID-19 is highly variable in its clinical presentation, ranging from asymptomatic infection to severe organ damage and death. We characterized the time-dependent progression of the disease in 139 COVID-19 inpatients by measuring 86 accredited diagnostic parameters, such as blood cell counts and enzyme activities, as well as untargeted plasma proteomes at 687 sampling points. We report an initial spike in a systemic inflammatory response, which is gradually alleviated and followed by a protein signature indicative of tissue repair, metabolic reconstitution, and immunomodulation. We identify prognostic marker signatures for devising risk-adapted treatment strategies and use machine learning to classify therapeutic needs. We show that the machine learning models based on the proteome are transferable to an independent cohort. Our study presents a map linking routinely used clinical diagnostic parameters to plasma proteomes and their dynamics in an infectious disease.

O-112 Outcomes of random-start ovarian stimulation protocols as a possible evidence of the theory of antral follicles continuous recruitment

Study question

We tried to validate the possibility and efficiency of ovarian stimulation (OS) started on any day of the menstrual cycle, based on a theory of continuous recruitment of antral follicles.

Summary answer

Formation of a pool of follicles with higher sensitivity to gonadotropic stimulation occurs several times during the menstrual cycle (MC).

What is known already

According to classical concepts and fundamental positions formulated in the middle of the last century, follicular recruitment occurs only once during the menstrual cycle - in the early follicular phase. Nowadays there is increasing evidence to suggest that there are multiple (two or three) antral follicular waves of recruitment during the MC. Also some researchers state that the process of follicle recruitment is continuous.

Study design, size, duration

This prospective clinical study was conducted at the V.I. Kulakov NMRC for OG&Pof Russia. The study included female cancer patients seeking retrieval and cryopreservation of oocytes and/or embryos before cancer treatment. 240 patients were selected for the study. The patients were divided into 5 groups depending on the cycle day on the moment when ovarian stimulation was initiated. All patients signed an informed consent form approved by the Ethics Committee.

Participants/materials, setting, methods

The 1st group consisted of patients who started standart OS from 1 to 5 days of the cycle (n = 65); the 2nd - from 6 to 10 (n = 36), the 3rd - from 11 to 15 (n = 45), the 4th - from 16 to 22 (n = 44), the 5th - from 23 to 28 (n = 50). In the late follicular and luteal phase we performed OS without a pituitary modulator. The comparative analysis included features of oo-, embryogenesis and steroidogenesis.

Main results and the role of chance

The mean age, BMI and AMH were not different among groups. There were no LH rise or OHSS signs noticed in any groups, despite that OS in late follicular and luteal phase of the MC was performed with no GnRH antagonist addition.There was no statistically significant difference in the duration of stimulation, starting doses, total dose of FSH and HMG. The largest number of oocyte cumulus complexes was obtained in the 5th group (11 (9–21) vs 7 (3,5–15,5) in the 1st group, p = 0,030). The greatest number of mature oocytes was obtained in the 4th and 1st groups. In the 2nd group the largest number of immature oocytes was obtained (37 (9.1%)). A smaller number of mature oocytes (165 (61.8%) vs 492 (72.9%) and 314 (77.5%), p = 0.001) was obtained in group 2 (compared with the 1st and the 4th groups), when stimulation was started in the presence of a dominant follicle . These periods coincided with higher estradiol and lower FSH serum levels. Based on our data the optimal moment for effective OS initiation starts with the decrease in serum estradiol which is approximately 48 hours before the menstrual bleeding.

Limitations, reasons for caution

The presented results could be applied mainly to young patients with high and normal ovarian reserve, who were in the main study group. In patients with low ovarian reserve, short menstrual cycle and early ovulation an issue of favorable time points for the initiation of OS should be resolved individually.

Wider implications of the findings

The data collected during our research could possibly contribute to future personification of OS protocols. Tailoring the ovarian stimulation protocols to the needs of the patients could decrease time needed for completing the protocol without affecting oocyte yield or their maturity.

Trial registration number

none

Feasibility of in vitro maturation of oocytes collected from patients with malignant ovarian tumors undergoing fertility preservation

OBJECTIVE

In vitro maturation of oocytes collected from oophorectomy samples might be a promising approach in the field of oncofertility. In this study, we evaluate the feasibility of in vitro maturation of oocytes collected from oophorectomy samples in patients with ovarian tumors.

METHODS

This prospective observational study included 27 patients with malignant ovarian tumors. Patients underwent oophorectomy and ovarian tissue was examined for the presence of immature cumulus-oocyte complexes. These were matured in vitro for 48 hours. Mature oocytes were vitrified or used for fertilization. Serum anti-müllerian hormone (AMH) levels were analyzed in 11 patients and cancer antigen 125 (CA125) levels in 16 patients.

RESULTS

In this study, 99 cumulus-oocyte complexes were obtained from 17 patients (63%). The mean (SE) age of the patients was 33.47±1.86 years (range 16-44). A total of 14 patients had ovarian cancer (IA-IVB), one patient had ovarian cancer IC and endometrial cancer IA, one patient had endometrial cancer stage IA with metastasis into the ovary, and one patient had cervical cancer stage IIB with metastasis in the ovary. Oocytes were not obtained in 10 patients who had diminished ovarian reserve due to age (>38 years), chemotherapy, or previous surgical treatment. On average, 5.8 cumulus-oocyte complexes were obtained per patient. The maturation rate was 40.4% with an average of 2.8 metaphase II oocytes per patient. As a result of the study, 3 blastocysts in 3 patients and 22 oocytes in 9 patients were vitrified.

CONCLUSIONS

In vitro maturation of oocytes collected from oophorectomy samples in patients with malignant ovarian tumors may result in oocyte and blastocyst vitrification. However, it should be offered to patients before surgery and chemotherapy. This method might be most beneficial in patients younger than 38 years, with AMH serum levels >1 ng/mL and without a large tumor burden.

Improved maturation competence of ovarian tissue oocytes using a biphasic in vitro maturation system for patients with gynecological malignancy: a study on sibling oocytes

PURPOSE

To investigate the developmental competence of ovarian tissue oocytes from patients with gynecological tumors using a biphasic in vitro maturation system with capacitation (CAPA-IVM) in comparison with standard IVM.

METHODS

This sibling pilot study included 210 oocytes in 10 patients with gynecological malignancies. After ovariectomies, ovaries were cut into even halves and immature cumulus-oocyte complexes (COCs) were retrieved from the ovarian tissue. COCs were separately cultured in either a biphasic CAPA-IVM system for 53 h or in standard IVM for 48 h. After IVM, all COCs were denuded and mature oocytes were either vitrified (N=5) or used for ICSI (N=5). Embryos were cultured for 5-6 days and obtained blastocysts were vitrified.

RESULTS

Use of the CAPA-IVM system led to a higher meiotic maturation rate in ovarian tissue oocytes (OTO) compared to standard IVM (56 vs 35%, p=0.0045) and had a tendency to result in lower degeneration after IVM. Only the CAPA-IVM method supported blastocyst formation.

CONCLUSIONS

The biphasic in vitro maturation system improved the competence of OTO in comparison to the standard IVM method. The study suggests that fertility preservation programs could become more efficient using IVM after capacitation culture.

Cryopreservation of euploid blastocysts obtained after fertilization of in vitro matured ovarian tissue oocytes: a case report

With the increased rate of stable remission after gonadotoxic cancer treatment, new methods of fertility preservation are required in order to provide the best possible care for oncological patients. Here, we report an original case of euploid blastocyst cryopreservation after in vitro maturation of ovarian tissue oocytes (OTO IVM). Thirty-three oocytes were obtained from the ovarian tissue after ovariectomy in the breast cancer patient. Six out of 12 matured oocytes fertilized successfully and 3 blastocysts were formed. Genetic investigation for mutations associated with this type of malignancy found that the patient is not a carrier. Preimplantation genetic testing was performed only for aneuploidies and found all 3 blastocysts to be euploid and suitable for embryo transfer. Our study showed that the ovarian tissue oocytes matured in vitro have the potential for euploid blastocyst formation after ICSI which could be screened for aneuploidies and inherited mutations and then be vitrified in order to provide the best fertility preservation strategy for women with cancer.