Comparing thaw survival, implantation and live birth rates from cryopreserved zygotes, embryos and blastocysts

Sex ratio of offspring is not statistically altered following pre-implantation genetic testing under a specific sex selection policy

PURPOSE

To determine whether the use of pre-implantation genetic testing (PGT) under a specific sex selection policy is associated with alterations in offspring sex ratio.

METHODS

This was a single-center retrospective cohort study of singleton live births from January 2018-December 2020 achieved via single blastocyst non-PGT or PGT frozen embryo transfer (FET). Per institutional policy, sex may be disclosed following PGT. If both sexes are available and morphologic grade is similar, patients may select the sex of the embryo to be transferred. Demographics and cycle characteristics were compared between non-PGT vs. PGT cycles with Mann-Whitney U or χ2. Poisson regression with robust variance estimates was used to model the probability of female vs. male offspring among non-PGT vs. PGT cycles, reported as risk ratio (RR) and 95% confidence interval (CI).

RESULTS(S)

Among 541 live births, 350 (64.7%) were achieved with PGT and 191 (35.3%) without PGT. In both groups, female sex was more common, representing 59.4% of PGT-offspring and 55.0% of non-PGT offspring. After adjusting for potential confounders, the use of PGT was not significantly associated with an increased likelihood of female offspring (RR 1.04, 95% CI 0.98-1.11, p = 0.22).

CONCLUSION(S)

Singletons born following FET had a higher rate of female sex than male. Allowing sex selection per institutional policy did not increase this ratio. These results contrast with those of prior publications and should motivate individual centers to monitor their own sex ratios. As utilization of PGT increases, local, regional, and national monitoring will become increasingly important.

A proof of concept for a deep learning system that can aid embryologists in predicting blastocyst survival after thaw

The ability to understand whether embryos survive the thaw process is crucial to transferring competent embryos that can lead to pregnancy. The objective of this study was to develop a proof of concept deep learning model capable of assisting embryologist assessment of survival of thawed blastocysts prior to embryo transfer. A deep learning model was developed using 652 labeled time-lapse videos of freeze-thaw blastocysts. The model was evaluated against and along embryologists on a test set of 99 freeze-thaw blastocysts, using images obtained at 0.5 h increments from 0 to 3 h post-thaw. The model achieved AUCs of 0.869 (95% CI 0.789, 0.934) and 0.807 (95% CI 0.717, 0.886) and the embryologists achieved average AUCs of 0.829 (95% CI 0.747, 0.896) and 0.850 (95% CI 0.773, 0.908) at 2 h and 3 h, respectively. Combining embryologist predictions with model predictions resulted in a significant increase in AUC of 0.051 (95% CI 0.021, 0.083) at 2 h, and an equivalent increase in AUC of 0.010 (95% CI -0.018, 0.037) at 3 h. This study suggests that a deep learning model can predict in vitro blastocyst survival after thaw in aneuploid embryos. After correlation with clinical outcomes of transferred embryos, this model may help embryologists ascertain which embryos may have failed to survive the thaw process and increase the likelihood of pregnancy by preventing the transfer of non-viable embryos.

Development of a predictive model for luteal phase oocyte retrieval in poor responders undergoing natural cycle IVF

The aim of this study is the development of a prediction model indicating successful application of Oocyte Retrieval performed during the Luteal Phase (LuPOR) in poor responders, as defined by the retrieval of at least one MII oocyte. Recruitment included 1688 poor responders diagnosed as per Bologna Criteria, undergoing natural cycle ICSI between 2012 and 2020. Oocyte collections were performed during the follicular phase and during the luteal phase similarly. Antral Follicle Count (AFC), Estradiol (E₂) levels evaluated on both trigger days prior to Follicular Phase Oocyte Retrieval (FoPOR) and LuPOR, and the number of small follicles 8–12 mm that were not aspirated during FoPOR were identified as predictive factors indicative of an efficient LuPOR practice with an Area Under the Curve (AUC) of 0.86, 0.86, 0.89 as well as 0.82 respectively. The combination of the above-mentioned characteristics into a prediction model provided an AUC of 0.88, specificity and a sensitivity of 0.73 and 0.94 respectively and an accuracy of 0.89. The model provided a positive predictive value (PPV) of 93.5% and a negative predictive value (NPV) of 46.8%. The clinical conclusion of the present study aims to be of added value to the clinician, by providing a prediction model defining the POR population benefiting from LuPOR. The high PPV of this model may renders this tool helpful for the practitioner that considers LuPOR.

A comparison of fertility preservation outcomes in patients who froze oocytes, embryos, or ovarian tissue for medically indicated circumstances: a systematic review and meta-analysis

OBJECTIVE

To compare obstetric outcomes in patients cryopreserving reproductive cells or tissues before gonadotoxic therapy.

DESIGN

A literature search was conducted following PRISMA guidelines on Embase, Medline, and Web of Science. Studies reporting obstetric outcomes in cancer patients who completed cryopreservation of oocyte, embryo, or ovarian tissue were included.

SETTING

Not applicable.

PATIENT(S)

Cancer patients attempting pregnancy using cryopreserved cells or tissues frozen before cancer therapy.

INTERVENTION(S)

Oocyte, embryo, or ovarian tissue cryopreservation for fertility preservation in cancer.

MAIN OUTCOME MEASURE(S)

The total numbers of clinical pregnancies, live births, and miscarriages in women attempting pregnancy using cryopreserved reproductive cells or tissues were calculated. A meta-analysis determined the effect size of each intervention.

RESULT(S)

The search returned 4,038 unique entries. Thirty-eight eligible studies were analyzed. The clinical pregnancy rates were 34.9%, 49.0%, and 43.8% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. No significant differences were found among groups. The live birth rates were 25.8%, 35.3%, and 32.3% for oocyte, embryo, and ovarian tissue cryopreservation, respectively, with no significant differences among groups. The miscarriage rates were 9.2%, 16.9%, and 7.5% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. Significantly fewer miscarriages occurred with ovarian tissue cryopreservation than with embryo cryopreservation.

CONCLUSION(S)

This enquiry is required to counsel cancer patients wishing to preserve fertility. Although the limitations of this study include heterogeneity, lack of quality studies, and low utilization rates, it serves as a starting point for comparison of reproductive and obstetric outcomes in patients returning for family-planning after gonadotoxic therapy.

Factors associated with vitrification-warming survival in 6167 euploid blastocysts

PURPOSE

To understand the clinical factors associated with embryo survival after vitrification in a cohort of human blastocysts screened by preimplantation genetic testing for aneuploidy (PGT-A).

METHODS

Patient demographic, embryo, and cycle characteristics associated with failed euploid blastocyst survival were compared in a cohort of women (n = 6167) who underwent IVF-PGT-A.

RESULTS

Compared to those that survived warming, vitrified euploid embryos that failed to survive after warming came from IVF cycles with significantly higher estradiol levels at time of surge (2754.8 ± 1390.2 vs. 2523.1 ± 1190.6 pg/mL, p = 0.03), number of oocytes retrieved (19.6 ± 10.7 vs. 17.5 ± 9.8, p = 0.005), and basal antral follicle count (BAFC) (15.3 ± 8.5 vs. 13.9 ± 7.2, p = 0.05). Euploid embryos were less likely to survive warming if they came from cycles before 2015 (24.6% vs. 13.2%, p < 0.001), were cryopreserved on day 7 versus day 5 or 6 (9.1% vs. 3.0%, p < 0.001), underwent two trophectoderm biopsies (6.9% vs. 2.3%, p < 0.001), had a grade C inner cell mass (15.4% vs. 7.7%, p < 0.001), or were fully hatched (41.1% vs. 12.2%, p < 0.001). In the multivariate model, which controlled for relevant confounders, the association between decreased survival and increased BAFC, year of IVF cycle, double trophectoderm biopsy, and fully hatched blastocysts remained statistically significant.

CONCLUSION

Euploid embryos that are fully hatched at time of vitrification, come from patients with high ovarian reserve, or require repeat trophectoderm biopsy are less likely to survive vitrification-warming. Our results provide a framework for reproductive counseling and offer realistic expectations to patients about the number of embryos needed to achieve family building goals.

Predictors and outcomes in breast cancer patients who did or did not pursue fertility preservation

PURPOSE

Breast cancer is the most common cancer in reproductive age women, and treatment can affect fertility; however, there is often concern regarding the safety of increased estradiol (E₂) levels and potential delays in treatment with ovarian stimulation for fertility preservation (FP). The aim of this study was to compare recurrence and survival in breast cancer patients who pursued FP without concurrent letrozole to those who did not (non-FP).

METHODS

We reviewed charts of women with breast cancer who contacted the FP patient navigator (PN) at Northwestern University from 01/2005-01/2018. Oncology and fertility outcome data were collected. Data were analyzed by Chi-square test or regression, as appropriate. Kaplan-Meier curves were used to examine breast cancer recurrence and survival. Statistical analyses were performed with SPSS IBM Statistics 26.0 for Windows.

RESULTS

332 patients were included, of which 157 (47.3%) underwent FP. Median days to treatment after consulting the PN was 35 in the FP group and 21 in non-FP (p < 0.05). Cancer recurrence was noted in 7 (4.7%) FP patients and 13 (7.9%) non-FP patients (NS), and mortality in 5 (3.2%) FP patients and 7 (4.2%) non-FP patients (NS). Within the FP group, no significant differences were found in recurrence or mortality based on ER status, age, BMI, peak E₂ level or total gonadotropin dose. Likelihood of pursuing FP was primarily a function of age and parity, and was not affected by breast cancer stage. To date, 21 have used cryopreserved specimens, and 13 (62%) had a live birth.

CONCLUSIONS

FP is safe and effective in breast cancer patients, regardless of receptor status; E₂ elevations and the 2-week delay in treatment start are unlikely to be clinically significant. These findings are unique in that our institution does not use concomitant letrozole during stimulation to minimize E₂ elevations in breast cancer patients.

Does fresh single embryo transfer outcome predict the result of a subsequent vitrified-warmed blastocyst of the same cohort?

Reflecting the current trends, the utilization of frozen-thawed transfer cycles has been steadily increasing worldwide; outcome predictors of these cycles are therefore a major research goal. Our aim was to investigate whether the outcome of a fresh single blastocyst transfer (SBT) can serve as a prognostic factor for the subsequent vitrified-warmed SBT originating from the same cohort. A retrospective cohort study was performed at a single unit. Non-donor fresh cycles were analyzed as predictors of the following vitrified-warmed cycle. Only SBTs were included. Cycles designated to a freeze-all policy and cycles involving pre-implantation genetic analysis were excluded. A total of 1127 vitrified-warmed single blastocyst cycles were included. The indications for artificial reproductive technologies were comparable across the study groups. Vitrified-warmed cycles following a live birth outcome in the fresh cycle were more likely to result in a clinical pregnancy than those following a fresh cycle, which failed to reach a live birth. The same trend was observed for live birth rate following vitrified-warmed transfer in the fresh cycle. After correcting for possible confounders, age and embryo quality were significantly correlated with the chance for a live birth, but the previous fresh cycle did not affect the results. We therefore conclude that after adjustment for age, embryo quality and number of previous oocyte retrieval cycles, the fresh cycle outcome was not a significant influential factor for the following vitrified-warmed cycle.

Fertility preservation in women with early-stage gynecologic cancer: optimizing oncologic and reproductive outcomes

Almost all standard therapies for gynecologic cancer, including surgical intervention, gonadotoxic chemotherapy, and radiation therapy, threaten a woman's childbearing potential. Preservation of fertility should be discussed with premenopausal women with early-stage gynecologic cancer shortly after diagnosis and, for women who desire to preserve fertility, during treatment planning. Many authors have investigated both oncologic and reproductive outcomes following fertility-sparing therapy, and there is ongoing development of assisted reproduction techniques available to cancer patients and survivors. Women with early-stage (IA1-IB1) cervical cancer may be candidates for fertility-sparing cervical conization, simple trachelectomy, or radical trachelectomy. In women with stage I epithelial ovarian cancer, fertility-sparing surgery appears safe overall, although controversy remains in patients with high-risk features (eg, high pathologic grade, clear cell histology, or stage IC disease). In women with low-grade, early-stage endometrial cancer, hormonal therapy has emerged as a viable option. Criteria for patient selection for fertility-sparing therapy are not well defined, thus patients and providers must carefully discuss potential risks and benefits. In general, in carefully selected patients, survival outcomes do not appear to differ significantly between radical and fertility-sparing approaches. Women who undergo fertility-sparing therapies may experience a number of fertility and obstetric complications. Preconception counseling with high-risk obstetric specialists is important to optimize health before a woman attempts to conceive. Identifying appropriate candidates for fertility-sparing treatments, assessing fertility potential, and helping women conceive after cancer treatment is best accomplished through multidisciplinary collaboration between gynecologic oncologists and fertility specialists.

Novel aspects on gonadotoxicity and fertility preservation in lymphoproliferative neoplasms

The topic of fertility preservation in patients with a lymphoproliferative disease offers new aspects of debate, due to the introduction of novel chemotherapeutic regimens and small molecules in the clinical landscape. Cancer related infertility is mostly dependent on gonadotoxic treatments and fertile female patients are today addressed to the oocyte cryopreservation or to ovarian cortex fragment cryopreservation. These methods present advantages and disadvantages, which will be discussed in the present review, together with the options for male patients. The recent discovery of functional ovarian stem cells (OCSs) in woman ovarian cortex, opens new avenues offering a innovative procedure for fertility preservation through as model of regenerative medicine. Here, we review the gonadotoxic potential of "classical" chemotherapeutic treatments as well as of "novel" targeted therapies actually employed for lymphoproliferative neoplasms in young patients and revisit both the today available and future chances to preserve and restore fertility after the cancer healing.

Ovarian Stimulation Is Safe and Effective for Patients with Gynecologic Cancer

Purpose: To compare long-term outcomes of gynecologic cancer patients who pursued controlled ovarian hyperstimulation (COH) for fertility preservation (FP) with those who did not. Methods: Retrospective cohort, COH, and health outcomes in gynecologic cancer patients; data were analyzed by chi-square test, t-tests, and logistic regression. Results: Ninety patients with a gynecologic malignancy contacted the FP patient navigator: 45.6% (n = 41) had ovarian cancer, 25.6% (n = 23) endometrial cancer, 18.9% (n = 17) cervical cancer, 5.6% (n = 5) uterine cancer, and 4.4% (n = 4) multiple gynecologic cancers. From this cohort, 32 underwent COH, 43 did not, and 18 pursued ovarian tissue cryopreservation (OTC; 3 patients had both COH and OTC). Median age and type of cancer were not significantly different between the groups. COH patients had a range of 1-35 oocytes retrieved. Days to next cancer treatment in the COH group was 36 days; for those who declined COH, it was 22 days (not significant [NS], p > 0.05). There were two recurrences reported in the stimulation group and four in the no stimulation group (NS). Five deaths were reported, two in the stimulation group, none in the no stimulation group, and three in the OTC group (NS); 34% (n = 11) COH patients returned to use cryopreserved specimens, of which 45% (n = 5) had a live birth. Conclusion: Although time to next treatment was longer in the group of patients who underwent COH, this did not reach statistical significance. It appears that in selected patients with GYN malignancies, COH for oocyte or embryo cryopreservation is safe, with reasonable stimulation outcomes and no difference in long-term outcomes.

Ovarian stimulation is a safe and effective fertility preservation option in the adolescent and young adult population

PURPOSE

The aim of this study is to describe the multidisciplinary approach and controlled ovarian hyperstimulation (COH) outcomes in adolescent and young adult (AYA) patients (ages 13-21) who underwent oocyte cryopreservation for fertility preservation (FP).

METHODS

Multi-site retrospective cohort was performed from 2007 to 2018 at Northwestern University and Michigan University. Data were analyzed by chi-square test, t-test, and logistic regression.

RESULTS

Forty-one patients began COH of which 38 patients successfully underwent oocyte retrieval, with mature oocytes obtained and cryopreserved without any adverse outcomes. To treat this group of patients, we use a multidisciplinary approach with a patient navigator. When dividing patients by ages 13-17 vs. 18-21, the median doses of FSH used were 2325 and 2038 IU, the median number of mature oocytes retrieved were 10 and 10, and median number frozen oocytes were 11 and 13, respectively. Median days of stimulation were 10 for both groups. There was no statistical difference in BMI, AMH, peak E₂, FSH dosage, days stimulated, total oocytes retrieved, mature oocytes retrieved, and oocytes frozen between the two groups. Three patients were canceled for poor response.

CONCLUSION

COH with oocyte cryopreservation is a feasible FP option for AYAs who may not have other alternatives when appropriate precautions are taken, such as proper counseling and having a support team. These promising outcomes correspond to similar findings of recent small case series, providing hope for these patients to have genetically related offspring in the future.

Preserving fertility in female patients with hematological malignancies: a multidisciplinary oncofertility approach

Oncofertility is a new interdisciplinary field at the intersection of oncology and reproductive medicine that expands fertility options for young cancer patients. The most common forms of hematological malignancies that occur in girls and young women and therefore necessitate oncofertility care are acute lymphocytic leukemia, acute myeloid leukemia, non-Hodgkin's lymphoma, and Hodgkin's lymphoma. Aggressive gonadotoxic anticancer regimens including alkylating chemotherapy and total body irradiation are used often in treating girls and young women with hematological malignancies. The risks of gonadotoxicity and subsequent iatrogenic premature ovarian insufficiency and fertility loss depend mainly on the type and stage of the disease, dose of anticancer therapy as well as the age of the patient at the beginning of treatment. To avoid or at least mitigate the devastating complications of anticancer therapy-induced gonadotoxicity, effective and comprehensive strategies that integrate different options for preserving and restoring fertility ranging from established to experimental strategies should be offered before, during, and after chemotherapy or radiotherapy. A multidisciplinary approach that involves strong coordination and collaboration between hemato-oncologists, gynecologists, reproductive biologists, research scientists, and patient navigators is essential to guarantee high standard of care.

Assessing the impact of delayed blastulation using time lapse morphokinetics and preimplantation genetic testing in an IVF patient population

PURPOSE

There is clinical evidence that early cleavage timing parameters predictive of blastocyst development also correlate with embryo implantation potential. The aim of this study is to determine the developmental competency of embryos with delayed blastulation.

METHODS

Retrospective study performed from 2015 to 2016 at the Division of Reproductive Endocrinology and Infertility at Northwestern University.

RESULTS

A total of 2,292 embryos from 524 patients were included. Day 6 blastocysts had statistically significant longer times for every time point analyzed than day 5 blastocysts (p < 0.001). We found no statistically significant difference in euploidy rates between day 5 (44%) and day 6 (41%) embryos (p = 0.573). t7 and t8 time points were independent predictors of euploidy after controlling for day of biopsy (p < 0.015 and p < 0.014, respectively). Intrauterine pregnancy (IUP) and live birth (LB) were less likely to occur after transferring day 6 embryos (p = 0.0033 and p = 0.0359) without previous genetic testing. However, in embryos that undergo preimplantation genetic testing for aneuploidy (PGT-A), there were no significant differences in IUP or LB rates.

CONCLUSION

Early time-lapse points can be used to predict embryo development. Day of blastulation may be an independent predictor IUP, with day 6 blastocysts having lower pregnancy and live birth rates. Our data suggests that day 5 and day 6 PGT-A tested embryos show similar rates of euploidy, suggesting that differences in PR seen in the non-PGT-A tested group may be caused by factors other than aneuploidy. Genetic testing technologies in combination with time-lapse microscopy may provide further information to improve IVF outcomes.

Pregnancy rates after pre-implantation genetic screening for aneuploidy are only superior when trophectoderm biopsy is performed on hatching embryos

PURPOSE

In vitro fertilization with trophectoderm embryo biopsy and pre-implantation genetic screening with comprehensive chromosomal screening (PGS-CCS) for aneuploidy is becoming increasingly more popular. Embryos are cryopreserved and implanted in a subsequent frozen thawed embryo transfer cycle (FET). No studies have investigated differences in pregnancy outcomes by timing of trophectoderm biopsy relative to stages of blastocyst development.

METHODS

Retrospective study of all patients (n = 363) at a single IVF center between January 1, 2013 and December 31, 2016 undergoing single embryo transfer with PGS-CCS where embryos were cryopreserved with subsequent FET. Embryo expansion and grading was assessed both at the time of biopsy and transfer. Pregnancy rates were analyzed by embryo expansion and embryo grading.

RESULTS

Implantation, clinical pregnancy, and live birth rates improved significantly with increased embryo expansion at the time of embryo biopsy (P < 0.001). Pregnancy loss decreased with increases in embryo expansion prior to biopsy (P < 0.001). Superior live birth rates with PGS-CCS were seen when embryos were hatching at the time of biopsy (p < 0.001). For fresh and frozen embryo transfers without PGS-CCS, embryo expansion did not affect pregnancy outcomes.

CONCLUSIONS

PGS-CCS significantly increases implantation and live birth rates only if embryos are hatching at the time of biopsy. The embryo biopsy itself on a non-hatching embryo significantly damages the embryo in ways which are not reflected in future embryo expansion. IVF labs should wait until embryos hatch before performing trophectoderm biopsy.

Long-term outcomes in cancer patients who did or did not pursue fertility preservation

OBJECTIVE

To compare long-term outcomes of cancer patients who pursued fertility preservation (FP) with those who did not and compare random-start (RS) and menstrual cycle-specific (CS) protocols for FP.

DESIGN

Retrospective cohort.

SETTING

Single urban academic institution.

PATIENT(S)

Oncology patients who contacted the FP patient navigator, 2005-2015.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Time to cancer treatment, disease-free survival, and reproductive outcomes in FP versus no-FP patients and cycle outcomes for RS versus CS protocols. Data were analyzed by χ² and logistic regression.

RESULT(S)

Of 497 patients who met the inclusion criteria, 41% elected FP. The median number of days to cancer treatment was 33 and 19 days in the FP and no-FP groups, respectively. There was no difference in cancer recurrence or mortality. There were no differences in stimulation parameters, outcomes, or days to next cancer treatment in RS versus CS protocols. Twenty-one patients returned to use cryopreserved specimens, resulting in 16 live births. Eight of 21 returning patients used a gestational carrier. Thirteen FP (6.4%) and 16 no-FP (5.5%) patients experienced a spontaneous pregnancy.

CONCLUSION(S)

FP is both safe and efficacious for eligible cancer patients. Only 10% of patients returned to use cryopreserved specimens, and almost half used a gestational carrier, suggesting the need for further research into reproductive decision-making in cancer survivors.

The use of serum anti-Mullerian hormone (AMH) levels and antral follicle count (AFC) to predict the number of oocytes collected and availability of embryos for cryopreservation in IVF

AIM

To investigate the predictive value of anti-Mullerian hormone (AMH) and antral follicle count (AFC) on the final number of oocytes retrieved and the availability of embryos for cryopreservation in in vitro fertilization (IVF) cycles.

PATIENTS AND METHODS

In this prospective study, one hundred and twenty women in their first IVF treatment were enrolled. The short stimulation agonist protocol was used for controlled ovarian hyperstimulation in all cases. Serum AMH levels were measured during the menstrual cycle preceding treatment. AFC was measured in cycle day 2, just before starting ovarian stimulation.

RESULTS

A strong, positive correlation between AMH, AFC and the number of collected oocytes was found. The patients with available and suitable supplementary embryos for cryopreservation had higher levels of AMH and larger numbers of AFC.

CONCLUSION

AMH and AFC appear to be valuable markers mainly for ovarian reserve and response to IVF treatment. Serum AMH levels and AFC are significantly associated with the number of retrieved oocytes. Also, a positive correlation with the availability of supernumerary embryos suitable for cryopreservation was observed.

Freeze-all cycle for all normal responders?

PURPOSE

The purpose of this study is to evaluate the freeze-all strategy in subgroups of normal responders, to assess whether this strategy is beneficial regardless of ovarian response, and to evaluate the possibility of implementing an individualized embryo transfer (iET) based on ovarian response.

METHODS

This was an observational, cohort study performed in a private IVF center. A total of 938 IVF cycles were included in this study. The patients were submitted to controlled ovarian stimulation (COS) with a gonadotropin-releasing hormone (GnRH) antagonist protocol and a cleavage-stage day 3 embryo transfer. We performed a comparison of outcomes between the fresh embryo transfer (n = 523) and the freeze-all cycles (n = 415). The analysis was performed in two subgroups of patients based on the number of retrieved oocytes: Group 1 (4-9 oocytes) and Group 2 (10-15 oocytes).

RESULT(S)

In Group 1 (4-9 retrieved oocytes), the implantation rates (IR) were 17.9 and 20.5% (P = 0.259) in the fresh and freeze-all group, respectively; the ongoing pregnancy rates (OPR) were 31 and 33% (P = 0.577) in the fresh and freeze-all group, respectively. In Group 2 (10-15 oocytes), the IR were 22.1 and 30.1% (P = 0.028) and the OPR were 34 and 47% (P = 0.021) in the fresh and freeze-all groups, respectively.

CONCLUSION(S)

Although the freeze-all policy may be related to better in vitro fertilization (IVF) outcomes in normal responders, these potential advantages decrease with worsening ovarian response. Patients with poorer ovarian response do not benefit from the freeze-all strategy.

Artificial shrinkage of blastocoel using a laser pulse prior to vitrification improves clinical outcome

PURPOSE

Blastocysts contain a large amount of fluid in the blastocoel, which may pose a risk for ice crystal formation during vitrification. This study aimed to evaluate the effectiveness of laser-induced artificial shrinkage of blastocoel before vitrification on clinical outcome.

METHODS

Patients were divided into two groups: a control group with untreated, expanded blastocysts (n = 115) and a study group with blastocoel artificially eliminated by a laser pulse prior to vitrification (n = 309). Blastocyst survival, clinical pregnancy, and implantation rates were compared.

RESULT(S)

The survival rate was significantly higher in the study group compared with the control group (97.3 and 74.9 %, respectively; p > 0.01). The clinical pregnancy and implantation rates of the study group were significantly higher (p < 0.01) than that of the control group (clinical pregnancy, 67.2 vs. 41.1 %; implantation, 39.1 vs. 24.5 %.

CONCLUSION(S)

This study demonstrated that the removal of blastocoel fluid before vitrification by laser pulse of in vitro-produced human blastocysts significantly improves blastocyst survival, clinical pregnancy, and implantation rates.

Prediction model for aneuploidy in early human embryo development revealed by single-cell analysis

Aneuploidies are prevalent in the human embryo and impair proper development, leading to cell cycle arrest. Recent advances in imaging and molecular and genetic analyses are postulated as promising strategies to unveil the mechanisms involved in aneuploidy generation. Here we combine time-lapse, complete chromosomal assessment and single-cell RT-qPCR to simultaneously obtain information from all cells that compose a human embryo until the approximately eight-cell stage (n=85). Our data indicate that the chromosomal status of aneuploid embryos (n=26), including those that are mosaic (n=3), correlates with significant differences in the duration of the first mitotic phase when compared with euploid embryos (n=28). Moreover, gene expression profiling suggests that a subset of genes is differentially expressed in aneuploid embryos during the first 30 h of development. Thus, we propose that the chromosomal fate of an embryo is likely determined as early as the pronuclear stage and may be predicted by a 12-gene transcriptomic signature.

Sperm RNA as a Mediator of Genomic Plasticity

Sperm RNA has been linked recently to trans-generational, non-Mendelian patterns of inheritance. Originally dismissed as “residual” to spermatogenesis, some sperm RNA may have postfertilization functions including the transmission of acquired characteristics. Sperm RNA may help explain how trans-generational effects are transmitted and it may also have implications for assisted reproductive technologies (ART) where sperm are subjected to considerable, ex vivo manual handling. The presence of sperm RNA was originally a controversial topic because nuclear gene expression is switched off in the mature mammalian spermatozoon. With the recent application of next generation sequencing (NGS), an unexpectedly rich and complex repertoire of RNAs has been revealed in the sperm of several species that makes its residual presence counterintuitive. What follows is a personal survey of the science behind our understanding of sperm RNA and its functional significance based on experimental observations from my laboratory as well as many others who have contributed to the field over the years and are continuing to contribute today. The narrative begins with a historical perspective and ends with some educated speculation on where research into sperm RNA is likely to lead us in the next 10 years or so.

Cryopreservation of human embryos and its contribution to in vitro fertilization success rates

Cryopreservation of human embryos is now a routine procedure in assisted reproductive technologies laboratories. There is no consensus on the superiority of any protocol, and substantial differences exist among centers in day of embryo cryopreservation, freezing method, selection criteria for which embryos to freeze, method of embryo thawing, and endometrial preparation for transfer of frozen-thawed embryos. In the past decade, the number of frozen-thawed embryo transfer cycles per started in vitro fertilization (IVF) cycle increased steadily, and at the same time the percentage of frozen-thawed embryo transfers that resulted in live births increased. Currently, cryopreservation of human embryos is more important than ever for the cumulative pregnancy rate after IVF. Interestingly, success rates after frozen-thawed embryo transfer are now nearing the success rates of fresh embryo transfer. This supports the hypothesis of so called freeze-all strategies in IVF, in which all embryos are frozen and no fresh transfer is conducted, to optimize success rates. High-quality randomized controlled trials should be pursued to find out which cryopreservation protocol is best and whether the time has come to completely abandon fresh transfers.

Fertility preservation outcomes may differ by cancer diagnosis

CONTEXT

Cancer survival has improved significantly and maintaining fertility is both a major concern and an important factor for the quality of life in cancer patients.

AIMS

To explore differences in oocyte stimulation for fertility preservation (FP) patients based on cancer diagnosis.

SETTINGS AND DEIGN

Between 2005 and 2011, 109 patients elected to pursue FP at a single institution.

MATERIALS AND METHOD

In vitro fertilization (IVF) outcome variables between four cancer diagnostic groups (breast, gynecologic, lymphoma/leukemia and other) and age-matched male factor or tubal factor infertility IVF control group were compared.

STATISTICAL ANALYSIS

ANOVA and Chi-square analyses were employed to compare variables between the groups that were normally distributed. Kruskal-Wallis with subsequent Mann-Whitney U-test were used for data that were not normally distributed.

RESULTS

Women with gynecologic malignancies were significantly older than the women in the other three groups, but tended to have a better ovarian response. Women with hematologic malignancies were most likely to have been exposed to chemotherapy and had the longest stimulations with a similar number of oocytes retrieved. The age-matched IVF controls had higher peak estradiol levels, number of oocytes obtained, and fertilization rates when compared to cancer patients with or without a history of prior chemotherapy.

CONCLUSIONS

Factors including age, type of cancer and chemotherapy exposure, can influence response to ovarian stimulation. Discussing these findings with patients presenting for FP may aid in setting realistic treatment expectations.

Is cryopreservation of embryos a legitimate surrogate marker of embryo quality in studies of assisted reproductive technology conducted using national databases?

OBJECTIVE

To investigate whether cryopreservation of supernumerary embryos is a good surrogate for embryo quality.

DESIGN

Retrospective study of 6,859 assisted reproductive technology (ART) cycles from women aged <35 years with two fresh day 3 embryos transferred.

SETTING

National Society for Assisted Reproductive Technology Clinic Outcome Reporting System data from 2006-2008.

PATIENT(S)

Women undergoing ART.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Embryo quality (good, fair, or poor), cell number, and live births were compared for cycles with and without cryopreservation, using χ(2) to evaluate statistical significance. The association of freezing with embryo quality was examined using multiple logistic regression after adjusting for confounders (patient age, oocyte yield, intracytoplasmic sperm injection [ICSI], assisted hatching, male factor infertility).

RESULT(S)

Cycles with cryopreservation were more likely to have two embryos of good quality transferred (81.3% vs. 48.5%) and had more 8-cell embryos transferred (76.0% vs. 50.1%). Relative to cycles with two good embryos (good-good), the adjusted odds ratios (OR) for cryopreservation were: good-fair (OR = 0.301, 95% confidence interval [CI] = 0.257-0.354), fair-fair (OR = 0.308, 95% CI = 0.258-0.367), and any poor (OR = 0.058, 95% CI = 0.040-0.083). The live birth rate was 52.4% for cycles with freezing and 40.6% for cycles without.

CONCLUSION(S)

Embryo quality and cell number were both associated with embryo cryopreservation. However, although cryopreservation was a strong marker for good quality, not having cryopreservation did not reliably indicate poor quality, as almost half of those cycles had two good quality embryos.