Fifteen years of autologous oocyte thaw outcomes from a large university-based fertility center.

OBJECTIVE: To review the outcomes of patients who underwent autologous oocyte thaw after planned oocyte cryopreservation. DESIGN: Retrospective cohort study. SETTING: Large urban university-affiliated fertility center. PATIENT(S): All patients who underwent ≥1 autologous oocyte thaw before December 31, 2020. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The primary outcome was the final live birth rate (FLBR) per patient, and only patients who had a live birth (LB) or consumed all remaining inventory (cryopreserved oocytes and resultant euploid/untested/no result embryos) were included. The secondary outcomes were laboratory outcomes and LB rates per transfer. RESULT(S): A total of 543 patients underwent 800 oocyte cryopreservations, 605 thaws, and 436 transfers. The median age at the first cryopreservation was 38.3 years. The median time between the first cryopreservation and thaw was 4.2 years. The median numbers of oocytes and metaphase II oocytes (M2s) thawed per patient were 14 and 12, respectively. Overall survival of all thawed oocytes was 79%. Of all patients, 61% underwent ≥1 transfer. Among euploid (n = 262) and nonbiopsied (n = 158) transfers, the LB rates per transfer were 55% and 31%, respectively. The FLBR per patient was 39%. Age at cryopreservation and the number of M2s thawed were predictive of LB; the FLBR per patient was >50% for patients aged <38 years at cryopreservation or who thawed ≥20 M2s. A total of 173 patients (32%) have remaining inventory. CONCLUSION(S): Autologous oocyte thaw resulted in a 39% FLBR per patient, which is comparable with age-matched in vitro fertilization outcomes. Studies with larger cohorts are necessary.

Planned oocyte cryopreservation-10-15-year follow-up: return rates and cycle outcomes.

OBJECTIVE: To evaluate the outcomes of planned oocyte cryopreservation patients most likely to have a final disposition. DESIGN: Retrospective cohort study of all patients who underwent at least 1 cycle of planned oocyte cryopreservation between Jan 2005 and December 2009. SETTING: Large urban University-affiliated fertility center PATIENT(S): All patients who underwent ≥1 cycle of planned oocyte cryopreservation in the study period. INTERVENTION(S): None MAIN OUTCOME MEASURE(S): Primary outcome was the disposition of oocytes at 10-15 years. Secondary outcomes included thaw/warming types, laboratory outcomes, and live birth rates. Outcomes and variables treated per patient. RESULT(S): A total of 231 patients with 280 cycles were included. The mean age at the first retrieval was 38.2 years (range 23-45). A total of 3,250 oocytes were retrieved, with an average of 10 metaphase II frozen/retrieval. To date, the oocytes of 88 patients (38.1%) have been thawed/warmed, 109 (47.2%) remain in storage, 27 (11.7%) have been discarded, and 7 (3.0%) have been transported elsewhere. The return rate (patients who thawed/warmed oocytes) was similar by Society for Assisted Reproductive Technology age group. The mean age of patients discarding oocytes was 47.4 years (range, 40-57). Of the 88 patients who thawed/warmed oocytes, the mean age at the time of thaw/warming was 43.9 years (range, 38-50) with a mean of 5.9 years frozen (range, 1-12). Nine patients (10.2%) thawed/warmed for secondary infertility. A total of 62.5% of patients created embryos with a partner, and 37.5% used donor sperm. On average, 14.3 oocytes were thawed/warmed per patient, with 74.2% survival (range, 0%-100%) and a mean fertilization rate of 68.8% of surviving oocytes. Of 88 patients, 39 (44.3%) planned a fresh embryo transfer (ET); 36 of 39 patients had at least 1 embryo for fresh ET, and 11 had a total of 14 infants. Forty-nine of 88 patients (55.7%) planned for preimplantation genetic testing for aneuploidy, with a mean of 4.2 embryos biopsied (range, 0-14) and a euploidy rate of 28.9%. Of the 49 patients, 17 (34.7%) had all aneuploidy or no embryos biopsied. Twenty-four patients underwent a total of 36 single euploid ET with 18 live births from 16 patients. Notably, 8 PGT-A patients had a euploid embryo but no ET, affecting the future cumulative pregnancy rate. Overall, 80 patients with thaw/warming embryos had a final outcome. Of these, 20 had nothing for ET (arrested/aneuploid), and of the 60 who had ≥1 ET, 27 had a total of 32 infants, with a live birth rate of 33.8% (27/80). CONCLUSION(S): We report the final outcomes of patients most likely to have returned, which is useful for patient counseling: a utilization rate of 38.1% and a no-use rate of 58.9%, similar across age groups. Further studies with larger cohorts as well as epidemiologic comparisons to patients currently cryopreserving are needed.

Access to infertility care in a low-resource setting: bridging the gap through resident and fellow education in a New York City public hospital.

PURPOSE: Improving access to care is an issue at the forefront of reproductive medicine. We sought to describe how one academic center, set in the background of a large and diverse metropolitan city, cares for patients with extremely limited access to reproductive specialists. METHODS: The NYU Reproductive Endocrinology and Infertility (REI) Fellowship program provides a "fellow-run clinic" within Manhattan's Bellevue Hospital Center, which is led by the REI fellows and supervised by the REI attendings of the NYU Langone Health system. A description of the history of the hospital as well as the logistics of the fertility clinic is provided as a logistical template for implementation. RESULTS: The fellow-run fertility clinic at Bellevue hospital is held on two half days per month seeing approximately 150 new patients per year. The fertility workup, counseling, surgery, as well as ovulation induction, and early pregnancy management are offered within the construct of the fellowship and residency at NYU. Barriers to care and ways to circumvent those barriers are discussed in detail. CONCLUSION: By utilizing the ambition and construct of the OB/GYN programs, we greatly improve care for an otherwise underserved patient population by offering an efficient and optimal infertility workup and treatment in a population that would otherwise be without care. We utilize the framework of graduate medical education to provide autonomy, experience, and mentorship to both residents and fellows in our programs in an effort to provide a solution to combating inequity in infertility care.

Why do euploid embryos miscarry? A case-control study comparing the rate of aneuploidy within presumed euploid embryos that resulted in miscarriage or live birth using next-generation sequencing.

OBJECTIVE: To determine whether undetected aneuploidy contributes to pregnancy loss after transfer of euploid embryos that have undergone array comparative genomic hybridization (aCGH). DESIGN: Case-control study. SETTING: University-based fertility center. PATIENT(S): Cases included 38 patients who underwent frozen euploid ET as determined by aCGH, resulting in miscarriage. Controls included 38 patients who underwent frozen euploid ET as determined by aCGH, resulting in a live birth. INTERVENTION(S): Next-generation sequencing (NGS) protocols were internally validated. Saved amplified DNA samples from the blastocyst trophectoderm biopsies previously diagnosed as euploid by aCGH were reanalyzed using NGS. Cytogenetic reports of the products of conception for 20 of the pregnancies resulting in miscarriage were available for comparison. MAIN OUTCOME MEASURE(S): The incidence of aneuploidy and mosaicism using NGS within embryos resulting in miscarriage and live birth. RESULT(S): Of euploid embryos analyzed by aCGH resulting in miscarriage, 31.6% were mosaic and 5.2% were polyploid by NGS. The rate of chromosomal abnormalities was significantly higher in embryos resulting in miscarriage (36.8%) than in those resulting in live births (15.8%). The rate of mosaicism was twice as high among embryos resulting in miscarriage than those resulting in live birth, but this was not statistically significant. Next-generation sequencing detected more cases of mosaicism than cytogenetic analysis of products of conception. CONCLUSION(S): Undetected aneuploidy may increase the risk of first trimester pregnancy loss. Next-generation sequencing may detect mosaicism and triploidy more frequently than aCGH, which could help to identify embryos at high risk of miscarriage. Mosaic embryos, however, should not be discarded as some can result in live births.

Discrepant diagnosis rate of array comparative genomic hybridization in thawed euploid blastocysts.

PURPOSE: Preimplantation genetic screening (PGS) and diagnosis (PGD) with euploid embryo transfer is associated with improved implantation and live birth rates as compared to routine in vitro fertilization. However, misdiagnosis of the embryo is a potential risk. The purpose of this study was to investigate the clinical discrepant diagnosis rate associated with transfer of trophectoderm-biopsied blastocysts deemed to be euploid via array comparative genomic hybridization (aCGH). METHODS: This is a retrospective cohort study including cycles utilizing PGS or PGD with trophectoderm biopsy, aCGH, and euploid embryo transfer at a large university-based fertility center with known birth outcomes from November 2010 through July 2014 (n = 520). RESULTS: There were 520 embryo transfers of 579 euploid embryos as designated by aCGH. Five discrepant diagnoses were identified. Error rate per embryo transfer cycle was 1.0 %, 0.9 % per embryo transferred, and 1.5 % per pregnancy with a sac. The live birth (LB) error rate was 0.7 % (both sex chromosome errors), and the spontaneous abortion (SAB) error rate was 17.6 % (3/17 products of conception tested, but could range from 3/42 to 7/42). No single gene disorders were mistakenly selected for in any known cases.  CONCLUSIONS: Although aCGH has been shown to be a highly sensitive method of comprehensive chromosome screening, several possible sources of error still exist. While the overall error rate is low, these findings have implications for counseling couples that are contemplating PGS and PGD with aCGH.

Deliveries from trophectoderm biopsied, fresh and vitrified blastocysts derived from polar body biopsied, vitrified oocytes.

This longitudinal study reports preliminary findings of six patients who underwent first polar body biopsy followed by oocyte vitrification. All oocytes were warmed, inseminated by intracytoplasmic sperm injection and cultured to blastocyst. All suitable blastocysts underwent trophectoderm biopsy for aneuploidy screening, and supernumerary blastocysts were vitrified. Euploid blastocysts were transferred either fresh or in a subsequent programmed cycle. Of the 91 metaphase II oocytes, 30 had euploid first polar bodies. Development to blastocyst was more likely in oocytes with a euploid first polar body (66.7% versus 24.6%; P < 0.001). Nineteen euploid blastocysts were produced: 10 from oocytes with a euploid first polar body and nine from oocytes with an aneuploid first polar body. Five out of six patients (83%) had a live birth or ongoing pregnancy at the time of analysis. Eleven euploid blastocysts have been transferred and seven implanted (64%). Although the chromosomal status of the first polar body was poorly predictive of embryonic ploidy, an association was found between chromosomal status of the first polar body and development to blastocyst. Further study is required to characterize these relationships, but proof of concept is provided that twice biopsied, twice cryopreserved oocytes and embryos can lead to viable pregnancies.

Baby budgeting: oocyte cryopreservation in women delaying reproduction can reduce cost per live birth.

OBJECTIVE: To determine whether oocyte cryopreservation for deferred reproduction is cost effective per live birth using a model constructed from observed clinical practice. DESIGN: Decision-tree mathematical model with sensitivity analyses. SETTING: Not applicable. PATIENT(S): A simulated cohort of women wishing to delay childbearing until age 40 years. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Cost per live birth. RESULT(S): Our primary model predicted that oocyte cryopreservation at age 35 years by women planning to defer pregnancy attempts until age 40 years would decrease cost per live birth from $55,060 to $39,946 (and increase the odds of live birth from 42% to 62% by the end of the model), indicating that oocyte cryopreservation is a cost-effective strategy relative to forgoing it. If fresh autologous assisted reproductive technology (ART) was added at age 40 years, before thawing oocytes, 74% obtained a live birth, and cost per live birth increased to $61,887. Separate sensitivity analyses demonstrated that oocyte cryopreservation remained cost effective as long as performed before age 38 years, and more than 49% of those women not obtaining a spontaneously conceived live birth returned to thaw oocytes. CONCLUSION(S): In women who plan to delay childbearing until age 40 years, oocyte cryopreservation before 38 years of age reduces the cost to obtain a live birth.

Changing ovarian stimulation parameters in a subsequent cycle does not increase the number of euploid embryos.

OBJECTIVE: To compare the euploidy outcome in patients that underwent 2 ovarian stimulation cycles with trophectoderm biopsy. DESIGN: Retrospective repeated-measures cohort study. SETTING: University-based fertility center. PATIENT(S): A total of 116 patients, from 2011 through 2013, that underwent 2 ovarian stimulation cycles followed by trophectoderm biopsy with array comparative genomic hybridization. INTERVENTION(S): Days of stimulation, average diameter of the 2 lead follicles on day of trigger, dose of gonadotropins, type of cycle (gonadotropin-releasing hormone [GnRH] antagonist, GnRH-antagonist plus clomiphene citrate [CC], microdose GnRH agonist). MAIN OUTCOME MEASURE(S): Number of euploid embryos. RESULT(S): Patients were analyzed based on whether they had ≥1 euploid embryos in their first cycle vs. none. There was no increase in the number of euploid embryos with more days of stimulation or increases in the dose of gonadotropins in either group. Significantly more euploid embryos were seen in patients who had no euploid embryo(s) in the first cycle (Group 0) that had CC added to a GnRH-antagonist cycle (1.11 more euploid embryos) or were triggered when follicle sizes were 2 mm larger (0.40 euploid embryos), but these increases were not significant compared with a control group. Patients with euploid embryo(s) in the first cycle (Group 1) had significantly more euploid embryos when daily dose was increased by 75-149 international units, but this relationship was not significant compared with a control group with no increase in daily dose. CONCLUSION(S): No specific intervention increased the number of euploid embryos within the same patient any more than simply repeating a similar stimulation cycle. An attempt was made to control for interpatient variability, but individual patients have considerable intercycle variability.

Association of body mass index with embryonic aneuploidy.

OBJECTIVE: To determine whether an association exists between body mass index (BMI) and embryo ploidy in patients undergoing in vitro fertilization (IVF) with trophectoderm biopsy and 24-chromosome preimplantation genetic screening (PGS). DESIGN: Retrospective cohort study. SETTING: University-based fertility center. PATIENT(S): 279 women aged 20-45 years with documented height and weight from the day of oocyte retrieval who underwent 24-chromosome PGS between 2010 and 2013. INTERVENTION(S): None. PRIMARY OUTCOMES: number and percentage of euploid embryos. RESULT(S): Patients were grouped by World Health Organization (WHO) BMI class: underweight (<18.5, n = 11), normal weight (18.5-24.9, n = 196), overweight (25-29.9, n = 50), and obese (≥30, n = 22). Groups were similar by age (mean ± standard error of the mean: 37.5 ± 1.2 to 39.2 ± 0.9), ovarian reserve, and IVF cycle parameters. There was no difference in the number or percentage of euploid embryos by BMI category (<18.5: 27.6% ± 8.5; 18.5-24.9: 34.5% ± 2.2; 25-29.9: 32.1% ± 4.3; ≥30: 30.9% ± 7.3). Age was inversely related to euploidy, but adjusted multivariate regression models failed to demonstrate a statistically significant relationship between BMI and euploidy in underweight (adjusted odds ratio [AOR] 0.44; 95% confidence interval [CI], 0.09-2.10), overweight (AOR 0.90; 95% CI, 0.43-2.00), or obese (AOR 0.74; 95% CI, 0.25-2.20) patients compared with the normal-weight reference group. CONCLUSION(S): No statistically significant relationship was identified between BMI and euploidy in an otherwise homogenous cohort of patients undergoing IVF with PGS, suggesting that the negative impact of overweight and obesity on IVF and reproductive outcomes may not be related to aneuploidy.

In vitro fertilization with preimplantation genetic screening improves implantation and live birth in women age 40 through 43.

PURPOSE: In Vitro Fertilization is an effective treatment for infertility; however, it has relatively low success in women of advanced maternal age (>37) who have a high risk of producing aneuploid embryos, resulting in implantation failure, a higher rate of miscarriage or birth of a child with chromosome abnormalities. The purpose of this study was to compare the implantation, miscarriage and live birth rates with and without preimplantation genetic screening (PGS) of embryos from patients aged 40 through 43 years. METHODS: This is a retrospective cohort study, comparing embryos screened for ploidy using trophectoderm biopsy and array comparative genomic hybridization to embryos that were not screened. We compared pregnancy outcomes for traditional fresh IVF cycles with day 5 embryo transfers, Frozen Embryo Transfer (FET) cycles without PGS and PGS-FET (FET of only euploid embryos) cycles of patients with maternal ages ranging from 40 to 43 years, undergoing oocyte retrievals during the period between 1/1/2011 and 12/31/2012. RESULTS: The implantation rate of euploid embryos transferred in FET cycles (50.9%) was significantly greater than for unscreened embryos transferred in either fresh (23.8%) or FET (25.4%) cycles. The incidence of live birth per transferred embryo for PGS-FET (45.5%) was significantly greater than for No PGS fresh (15.8%) or No PGS FET (19.0 %) cycles. The incidences of live birth per implanted sac for PGS FET cycles (89.3%), No PGS fresh cycles (66.7%) and No PGS FET cycles (75.0%) were not significantly different. CONCLUSIONS: The present data provides evidence of the benefits of PGS with regard to improved implantation and live birth rate per embryo transferred.

Long-term cryopreservation of human oocytes does not increase embryonic aneuploidy.

OBJECTIVE: To determine if long-term cryopreservation of human oocytes affects oocyte developmental competence, blastocyst euploidy, or live-birth rates. DESIGN: Retrospective cohort study. SETTING: University-based fertility center. PATIENT(S): A total of 33 patients with cryopreserved oocytes underwent oocyte thaw, blastocyst culture, trophectoderm biopsy, and 24-chromosome preimplantation genetic screening (PGS) with array comparative genomic hybridization between December 2011 and July 2014; subjects were compared with 2:1 age-matched controls with fresh oocytes whose embryos underwent trophectoderm biopsy and PGS during the same period. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Rates of fertilization, blastulation, euploidy, implantation, and live birth. RESULT(S): Thirty-three patients (mean age 36.2 ± 3.8 y) thawed 475 oocytes that had been cryopreserved for a median of 3.5 years. Compared with 66 age-matched controls who underwent in vitro fertilization and PGS with fresh oocytes, embryos derived from cryopreserved oocytes demonstrated compromised blastocyst formation (54.5% vs. 66.2%) despite no impairment in fertilization (72.8% vs. 73.2%). Results showed no difference in the number of euploid blastocysts (1.7 ± 1.9 vs. 2 ± 2.5), percentage of euploid blastocysts (44.5% vs. 47.6%), rate of implantation (65% vs. 65%), or rate of live birth and ongoing pregnancy (62.5% vs. 55%) after 24-chromosome PGS with cryopreserved or fresh oocytes. CONCLUSION(S): Embryos derived from cryopreserved oocytes demonstrate impaired blastulation but equivalent rates of euploidy, implantation, and live birth compared with blastocysts derived from fresh oocytes, supporting the safety and efficacy of oocyte cryopreservation.

What do reproductive-age women who undergo oocyte cryopreservation think about the process as a means to preserve fertility?

OBJECTIVE: To better understand women's beliefs, priorities, and attitudes toward oocyte cryopreservation, to appreciate the extent of their reproductive education, and to track the reproductive paths of women who chose to undergo oocyte cryopreservation treatment. DESIGN: An anonymous 30-question survey. SETTING: Not applicable. PATIENT(S): From 2005-2011, 478 women completed ≥1 oocyte cryopreservation treatment cycle at our center to defer reproduction. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Demographics, motivations, desires, fertility knowledge, and outcomes related to oocyte cryopreservation. RESULT(S): A total of 183 patients (38%) completed the survey with >80% being aged ≥35 years; white; having no partner at time of oocyte cryopreservation; undergoing oocyte cryopreservation after an optimal reproductive age; feeling they had improved their reproductive future after oocyte cryopreservation and being empowered by the process; aware of age-related infertility; sensing popular media falsely portrayed the upper age limit for natural conception; and recorded lack of partner as the primary rationale for not yet starting a family. Nineteen percent of respondents added that workplace inflexibility contributed to their reproductive dilemma. Half stated they learned about oocyte cryopreservation from a friend; others became aware through a medical provider, the media, and the internet. Most patients (93%) have not yet returned to use their frozen oocytes; 11 stated they had. Overall, 20% reported a successful conception after oocyte cryopreservation. CONCLUSION(S): Surveying oocyte cryopreservation patients provides a glimpse into the knowledge base and motivations surrounding current female reproductive practices. Oocyte cryopreservation technology may prove to bridge the gap between reproductive prime and when a woman is realistically "ready" to have children.

Single thawed euploid embryo transfer improves IVF pregnancy, miscarriage, and multiple gestation outcomes and has similar implantation rates as egg donation.

PURPOSE: The objective of our study was to determine if trophectoderm biopsy, vitrification, array-comparative genomic hybridization and single thawed euploid embryo transfer (STEET) can reduce multiple gestations and yield high pregnancy and low miscarriage rates. METHODS: We performed a retrospective observational study comparing single thawed euploid embryo to routine age matched in vitro fertilization (IVF) patients that underwent blastocyst transfer from 2008 to 2011 and to our best prognosis group donor oocyte recipients (Donor). Our main outcome measures were implantation rate, clinical pregnancy rate, spontaneous abortion rate and multiple gestation rate. RESULTS: The STEET group had a significantly higher implantation rate (58 %, 53/91) than the routine IVF group (39 %, 237/613) while the Donor group (57 %, 387/684) had a similar implantation rate. The clinical pregnancy rates were not statistically different between the STEET and IVF groups. However, the multiple gestation rate was significantly lower in the STEET group (STEET 2 % versus IVF 34 %, Donor 47 %). CONCLUSIONS: STEET results in a high pregnancy rate, low multiple gestation rate and miscarriage rates. Despite the older age of STEET patients and transfer of twice as many embryos, the implantation rate for STEET was indistinguishable from that for egg donation. STEET offers an improvement to IVF, lowering risks without compromising pregnancy rate.

Live birth from previously vitrified oocytes, after trophectoderm biopsy, revitrification, and transfer of a euploid blastocyst.

Our objective is to describe a successful live birth from oocyte vitrification followed by thaw, fertilization, blastocyst culture, trophectoderm biopsy, vitrification, and subsequent thaw. Fifteen mature oocytes were frozen from a patient with uterine factor infertility. Thirteen oocytes survived the thaw, and five underwent trophectoderm biopsy and were refrozen. Three euploid embryos were obtained. A single euploid embryo was transferred in the second thaw cycle to a known recipient leading to the delivery of a normal male infant. This case report is proof of the concept that preimplantation screening and diagnosis is an option for fertility preservation patients.

Idiopathic recurrent miscarriage is caused mostly by aneuploid embryos.

OBJECTIVE: To determine any beneficial effects of preimplantation genetic screening (PGS) of all chromosomes by array comparative genomic hybridization (aCGH), with either day 3 or blastocyst biopsy, for idiopathic recurrent pregnancy loss (RPL) patients compared with their expected loss rate. DESIGN: Case series report. SETTING: Multiple fertility centers. PATIENT(S): A total of 287 cycles of couples with idiopathic RPL (defined as two or more losses). INTERVENTION(S): PGS was done with day 3 biopsy (n = 193) or blastocyst biopsy (n = 94), followed by analysis with aCGH. MAIN OUTCOME MEASURE(S): Spontaneous abortion rate, euploidy rate. RESULT(S): A total of 2,282 embryos were analyzed, of which 35% were euploid and 60% were aneuploid. There were 181 embryo transfer cycles, of which 100 (55%) became pregnant with an implantation rate of 45% (136 sacs/299 replaced embryos) and 94 pregnancies (92%) were ongoing (past second trimester) or delivered. The miscarriage rate was found to be only 6.9% (7/102), compared with the expected rate of 33.5% in an RPL control population and 23.7% in an infertile control population. CONCLUSION(S): Current PGS results with aCGH indicate a significant decrease in the miscarriage rate of idiopathic RPL patients and high pregnancy rates. Furthermore, this suggests that idiopathic recurrent miscarriage is mostly caused by chromosomal abnormalities in embryos.

Is intracytoplasmic sperm injection overused?

PURPOSE: We determined whether the use of intracytoplasmic sperm injection in couples who previously underwent intracytoplasmic sperm injection cycles elsewhere could be decreased without compromising the pregnancy rate. MATERIALS AND METHODS: At our university in vitro fertilization-embryo transfer center we retrospectively analyzed the records of 149 fresh, in vitro fertilization-embryo transfer cycles in patients who underwent intracytoplasmic sperm injection elsewhere and subsequent fertilization by insemination only (all insemination group) or half insemination and half intracytoplasmic sperm injection at our center. We compared fertilization, implantation, clinical pregnancy and live birth rates. RESULTS: The fertilization rate was 74% and 73% for the all insemination and the half intracytoplasmic sperm injection groups, respectively. In the latter group 69% of inseminated and 78% of intracytoplasmic sperm injected oocytes were fertilized. No cycle showed complete fertilization failure. No statistically significant difference in the live birth rate was found between the 2 groups. CONCLUSIONS: More stringent criteria for intracytoplasmic sperm injection do not compromise the clinical outcome and reasonable fertilization can be achieved whether or not intracytoplasmic sperm injection is performed. Thus, although intracytoplasmic sperm injection is one of the greatest advances in our field, it is overused and should only be done for clinically proven indications.

Retrospective analysis of outcomes following transfer of previously cryopreserved oocytes, pronuclear zygotes and supernumerary blastocysts.

Oocyte cryopreservation still bears the experimental label. Remarkable innovation in this field has led to immense improvement in clinical outcomes and has even resulted in outcomes comparable to those achieved following fresh embryo transfers. Such success has prompted this centre to investigate outcomes of cryopreservation options (oocyte versus pronuclear zygote versus supernumerary day-5 blastocyst after fresh embryo transfer). This study retrospectively analysed 200 cryopreservation cycles which were divided into three groups according to cryopreservation option, which were all cultured to blastocyst-stage post thaw/warming from January 2005 to December 2008, and compared them with 400 fresh embryo transfer cycles from the same time period. When compared with fresh embryo transfer, frozen embryo transfers originating from previously cryopreserved oocytes or pronuclear zygotes resulted in similar implantation, pregnancy and live-birth rates; however, frozen embryo transfers originating from supernumerary day-5 blastocysts resulted in lower outcomes. Thus, oocyte and/or pronuclear zygote cryopreservation appear to be the most viable options for women desiring fertility preservation. Cryopreservation of supernumerary blastocysts may lead to a slightly lower live-birth rate since the best-quality blastocysts are generally transferred during the fresh embryo transfer attempt.