Metabolomic Analysis Evidences That Uterine Epithelial Cells Enhance Blastocyst Development in a Microfluidic Device.

Here we report the use of a microfluidic system to assess the differential metabolomics of murine embryos cultured with endometrial cells-conditioned media (CM). Groups of 10, 1-cell murine B6C3F1 × B6D2F1 embryos were cultured in the microfluidic device. To produce CM, mouse uterine epithelial cells were cultured in potassium simplex optimized medium (KSOM) for 24 h. Media samples were collected from devices after 5 days of culture with KSOM (control) and CM, analyzed by reverse phase liquid chromatography and untargeted positive ion mode mass spectrometry analysis. Blastocyst rates were significantly higher (p < 0.05) in CM (71.8%) compared to control media (54.6%). We observed significant upregulation of 341 compounds and downregulation of 214 compounds in spent media from CM devices when compared to control. Out of these, 353 compounds were identified showing a significant increased abundance of metabolites involved in key metabolic pathways (e.g., arginine, proline and pyrimidine metabolism) in the CM group, suggesting a beneficial effect of CM on embryo development. The metabolomic study carried out in a microfluidic environment confirms our hypothesis on the potential of uterine epithelial cells to enhance blastocyst development. Further investigations are required to highlight specific pathways involved in embryo development and implantation.

Comparison of Embryo and Clinical Outcomes in Different Types of Incubator Between Two Different Embryo Culture Systems.

This study aimed to compare the clinical outcomes of an oxidative stress-reducing embryo culture system (ORES) containing compounds that minimize intercellular oxidative stress, with those of a standard embryo culture system (StES). Furthermore, we investigated the efficiency of the ORES regarding the type of incubator used (time-lapse incubator [TLI] or non-time-lapse dry incubator [non-TLI]) and maternal age. In this retrospective study, we analyzed 3610 oocyte retrieval cycles (in 2537 patients) and 1726 single vitrified-warmed blastocyst transfer (SVBT) cycles (in 1726 patients) performed in a single center between April 2018 and July 2019. Transfers of single vitrified-warmed blastocysts, confirmed by fetal heartbeat, were used to assess clinical outcomes. The clinical outcomes of ORES and StES were compared in both TLI and non-TLI. Groups were stratified according to maternal age (≤39 years old, young age group; ≥40 years old, advanced age group). A significant difference in ongoing pregnancy rates was observed between the ORES and StES groups when non-TLI was used (34.9 vs. 27.0%, respectively; p < 0.05), unlike when TLI was used. Furthermore, ongoing pregnancy rates were significantly higher in the ORES group (24.8%) than in the StES group (14.9%) in the advanced age group, unlike in the young age group when non-TLI was used. In conclusion, compared to StEs, the ORES during all in vitro fertilization procedures improved ongoing pregnancy rates in the advanced age group using the non-TLI.

Técnicas de Reproducción Humana asistida de alta complejidad / Human Reproduction Techniques high complexity assisted

INTRODUCCIÓN: La infertilidad es definida por la Organización Mundial de la Salud (OMS) como la patología del sistema reproductor caracterizada por la incapacidad de lograr un embarazo clínico después de 12 meses o más de relaciones sexuales no protegidas.[1] Las técnicas de alta complejidad son aquellos procedimientos que incluyen la manipulación de gametos, o embriones humanos para generar el embarazo. Entre las técnicas incluidas se encuentra la fertilización in-vitro (FIV) y la inyección intra-citoplasmática de espermatozoides (ICSI), transferencia de embriones y criopreservación de los mismos, la donación de ovocitos y embriones y el tratamiento de útero subrogado. [1,2]. En el año 2015 se reglamentó el acceso a las técnicas de reproducción humana asistida de alta complejidad en el Uruguay. La Ley Nº 19.167/013, los Decretos Nº 84/015 y N° 46/017, reglamentaron la financiación de las mencionadas técnicas.[3] Para el acceso a la cobertura las pacientes deberán tener una edad mayor de 18 y menor de 40, y deben cumplir con los criterios establecidos en la normativa de cobertura financiera.[2] El 17 de Agosto del 2020, mediante Decreto del Poder Ejecutivo se modifica la accesibilidad a las técnicas de Reproducción Humana Asistida, eliminado el incremento de los copagos según número de intentos, permitiendo un mayor alcance de la población objetivo.[4] Son tres las clínicas de fertilidad habilitadas en 2015 por el Ministerio de Salud Pública, a realizar procedimientos financiados por el Fondo Nacional de Recursos; Clínica Suizo Americana (CSA), Centro de Esterilidad Montevideo (CEM), y Centro de Reproducción Humana ( CERHIN). OBJETIVOS: Conocer el resultado de las técnicas de reproducción humana asistida de alta complejidad financiadas por el Fondo Nacional de Recursos desde el inicio de la cobertura. METODOLOGÍA: El presente es un estudio observacional retrospectivo, de una cohorte de pacientes usuarias de los procedimientos de RHA, basados en registros secundarios del Fondo Nacional de Recursos y Ministerio de Salud. De acuerdo a los objetivos específicos planteados se consideraron dos puntos de corte diferentes: para el 1er objetivo se tomaron aquellas mujeres incluidas en la cobertura financiera de las técnicas de reproducción humana asistida, desde el inicio de la cobertura en abril de 2015 hasta el 31 de diciembre de 2019. Para el análisis del segundo objetivo se evaluaron los nacidos vivos producto de las técnicas de reproducción humana asistida realizadas hasta el 31 de marzo de 2019 (Nacidos Vivos hasta diciembre de 2019). RESULTADOS: Caracterizar a las pacientes que hicieron uso del programa de RHA desde el inicio de cobertura hasta diciembre de 2019. La caracterización será en función de la edad, clínica de fertilidad, departamento de procedencia y tipo de prestador. CONCLUSIONES: Hasta diciembre de 2019 un total de 3.264 mujeres hicieron uso de las prestaciones financiadas por el Fondo Nacional de Recursos de técnicas de Reproducción Humana Asistida de alta complejidad, atribuyéndose a marzo de 2019 como resultado un total de 1.008 Nacidos Vivos producto de las técnicas financiadas (nacidos vivos hasta diciembre 2019). El corrimiento de la edad de inicio de la maternidad, ha hecho a las técnicas de Reproducción Asistida una opción en el tratamiento de la infertilidad de las parejas. Año a año, se incluyen aproximadamente 700 mujeres a la cobertura por el FNR, la actual disminución de los copagos y la extensión de edad de maternidad proyectan un número de mujeres a financiar creciente. La edad media de presentación ha variado en función del marco normativo, presentado al 2019 un promedio de 36,19 años (el más bajo desde el inicio de la cobertura), la modificación en la edad de presentación seguramente influya en resultados futuros tanto para gestaciones como para Nacidos Vivos. La evolución temporal muestra anualmente una tendencia creciente en la elección de una de las clínicas, observándose la siguiente distribución entre las clínicas con los siguientes porcentajes de distribución: CEM (año 2015 el 64.4%, en 2019 80,4%), CSA (año 2015 22,7%, en 2019 14.5%), Cerhin (año 2015 12.9%, en 2019 5.1%). La mayoría de las transferencias embrionarias evaluadas pertenecieron a transferencias en fresco (60.7%), superando el número de transferencias con embriones criopreservados. Los resultados mostraron una mayor tasa de parto en transferencias de criopreservados respecto a transferencias en fresco, en todos los grupos etarios e independiente de las clínicas de RHA esto debido a las mejores condiciones del endometrio al momento de la implantación. La tasa de parto en relación a la transferencia cae con el aumento de la edad materna, siendo el grupo menor a 35 años el que presentó mejores resultados. En los grupos etarios analizados Uruguay se presenta con una Tasa de parto por transferencia global mejor a la reportada por el resto de los países (según el registro de Red Lara). Respecto a las clínicas de Reproducción Asistida en las categorías analizadas, una de las clínicas presentó mejores tasas de parto por transferencias independiente de la edad materna con valores puntuales favorables en todos los rangos etarios analizados. Los resultados de Ovodonación obtenidos son similares a los obtenidos para ovocitos propios, siendo imputados el 22% de las transferencias realizadas y el 21% del total de los nacidos vivos adjudicables a las técnicas de reproducción Asistida. En un total de 1.008 nacimientos, se presentó una proporción de embarazos múltiples de 20,1% con variabilidad entre clínicas (19,3%-26,2%).

Degenerated oocyte in the cohort adversely affects IVF outcome.

The presence of Degenerated Oocyte (DEG) was mostly described after intracytoplasmic sperm injection (ICSI), with fewer reports on DEG at the time of ovum pick-up (OPU). This study aims to assess morphokinetics of embryos cultured in a time-lapse incubator and compare cohorts with and without DEG at OPU. In a retrospective cohort study from January 1, 2016 until September 31, 2017 a total of 399 IVF/ICSI cycles and 2980 embryos were evaluated. In 81 of 399 cycles at least one DEG oocyte was observed at the time of OPU. The remaining 318 cycles with no DEG oocyte were compared as a control group. In the DEG group, significantly more oocytes were collected per patient (12.9 ± 7.2 vs. 10.1 ± 6.1. P < 0.001). Fertilization rate, pregnancy and clinical pregnancy rates were comparable between the two groups, however, the morphokinetics and developmental scores of the embryos were significantly worse in the DEG group, (KID 3.4 ± 1.6 vs. 3.2 ± 1.6 P = 0.002 and ESHRE 1.5 ± 1.1 vs. 1.4 ± 1.0 P = 0.046). Significantly more patients achieved top-quality embryos in the NON DEG group (58.8% vs. 53.0%, P = 0.03), however, comparable delivery rate was achieved in both groups. In the DEG group, the frequency of DEG oocyte per cycle was negatively correlated with pregnancy rate. GnRH agonist protocol and the 17-20G needle used for OPU were significant predictors for the presence of DEG oocyte at OPU. In conclusions DEG oocyte may negatively affect IVF outcome, however, younger patients, and significantly more oocytes collected in the DEG group compensate for the IVF results.

Successful vitrification of dromedary camel embryos using a novel embryo vitrification kit.

Embryos (n = 87) collected 8 days after mating and 7 days after ovulation were vitrified using a camel-specific vitrification kit. Vitrification solutions (VS) containing 20% foetal calf serum, with or without 2% bovine serum albumin (BSA) were used to cryopreserve embryos, in three steps VS1 (5 min), VS2 (5 min) and VS3 (30-35 s) at room temperature (RT) before being loaded into open pulled straws and immediately frozen in liquid nitrogen. Embryos were subsequently thawed in warming solutions (WS) in three steps: WS1 at 37 °C (1 min), WS2 at RT (5 min) then into holding media at RT (5-60 min) prior to transfer, in pairs, into recipient camels 6 days after ovulation. There were 42 of 43 embryos viable after vitrification in media without BSA and these were subsequently transferred into 21 recipient females which resulted in ten pregnancies 60 days after transfer (48% pregnancy rate). There were 38 of 44 viable embryos vitrified in media containing BSA that were transferred in pairs into 19 recipient females which resulted in five pregnancies 60 days after transfer (26% pregnancy rate; P > 0.05). Of the total 15 foetuses that developed to 60 days of gestation after vitrification, 11 resulted from embryos of 200-499 µm diameter and four from embryos of 500-700 µm diameter (P > 0.05). There were encouraging results with use of this novel vitrification kit for the commercial application of cryopreservation of camel embryos with a diameter of 300-550 µm.

Sealed culture system for supporting mouse preimplantation embryo development in vitro.

This study investigated the possibility of a sealed culture system in polymerase chain reaction (PCR) tubes to maintain embryo development. The embryo density that could support the development of 2-cell stage mouse embryos to the hatching stage was determined. At an embryo density of 1:2 (100 embryos cultured in 200µL CZB medium that had been pretreated with a reference gas containing 5% O2), the developmental rate was higher and fewer embryos exhibited reactive oxygen species- or hypoxia-induced injury compared with other sealed culture groups. Expression of growth factors (insulin-like growth factor (IGF) 1, IGF2, epidermal growth factor and transforming growth factor-α) and their receptors was evaluated, with similar expression patterns seen for embryos in sealed culture (5% O2, embryo density of 1:2) compared with the control group (embryos cultured in microdrops and placed in a 37°C, 5% CO2 water-jacketed incubator; P>0.05). After transfer of blastocysts generated by the sealed culture into recipients, there were no obvious differences in the rate of normal live pups births between the sealed culture and control groups (P>0.05). Thus, the sealed embryo culture system in PCR tubes is feasible for use in situations which cannot use a traditional incubator, such as in space and during the transport of embryos.

Time-lapse technology for embryo culture and selection.

Culturing of human embryos in optimal conditions is crucial for a successful in vitro fertilisation (IVF) programme. In addition, the capacity to assess and rank embryos correctly for quality will allow for transfer of the potentially 'best' embryo first, thereby shortening the time to pregnancy, although not improving cumulative pregnancy and live birth rates. It will also encourage and facilitate the implementation of single embryo transfers, thereby increasing safety for mother and offspring. Time-lapse technology introduces the concept of stable culture conditions, in connection with the possibility of continuous viewing and documenting of the embryo throughout development. However, so far, even when embryo quality scoring is based on large datasets, or when using the time-lapse technology, the morphokinetic scores are still mainly based on subjective and intermittent annotations of morphology and timings. Also, the construction of powerful algorithms for widespread use is hampered by large variations in culture conditions between individual IVF laboratories. New methodology, involving machine learning, where every image from the time-lapse documentation is analysed by a computer programme, looking for patterns that link to outcome, may in the future provide a more accurate and non-biased embryo selection.

Unstable osmolality of microdrops cultured in non-humidified incubators.

PURPOSE: To investigate the stability of osmolality in non-humidified and humidified incubators for assisted reproductive technologies (ART). METHODS: Drops of three single-step culture media (media A, B, and C) were incubated for 5 or 6 days covered with four different mineral oils (oils A, B, C, and D) in non-humidified incubator A, non-humidified incubator B, or humidified incubator C to investigate the effects of incubator environment (humidification), drop volume, culture media, and mineral oil on the stability of osmolality in microdrops. RESULTS: A significant and linear increase was shown in the osmolality of 50-µL and 200-µL microdrops covered with mineral oil during 5 days incubation in non-humidified benchtop incubators. The maximum increase was 20 mOsm/kg, and the extent of the increase was affected by microdrop volume and possibly by the type of mineral oil used to cover the drops. In contrast, the osmolality of 50-µL and 200-µL microdrops did not change during 5 days incubation in a humidified benchtop incubator. CONCLUSIONS: Mineral oil alone may not adequately prevent gradual changes in the osmolality of low-volume microdrops during extended in vitro culture of human embryos in non-humidified incubators. As a result, the osmolality may increase to high enough levels to stress some human embryos and adversely affect clinical outcomes. We therefore recommend that the stability of osmolality should be given more consideration to ensure optimal culture conditions for ART.

Rabbit Whole Embryo Culture.

The rabbit is a mainstay of regulatory developmental toxicity testing; however, due to the historic absence of experimental tools for this species, there is a dearth of information about its fundamental embryology and the mechanisms underlying developmental toxicity. Relatively recently, there have been advances in the methods of rabbit whole embryo culture (WEC), and this has prompted an increase in understanding of rabbit embryogenesis. Described herein are the methods used to remove early somite-stage embryos (gestation day 9) and sustain their growth for 48 h. Although there are similarities to the well-described rodent WEC, there are also important differences. Akin to rodent WEC, the major phases of organogenesis can be investigated, including neural tube development, cardiac looping, segmentation, and the development of the anlagen of the optic and otic regions, craniofacial development, somites, and early limb bud development. Unlike the rodent, rabbit WEC requires the use of an apparatus that allows for the continuous gassing of embryos, and one may observe the expansion and closure of the visceral yolk sac around the embryo. After completion of the culture period, embryos are examined across several growth and developmental parameters including a quantitative morphological scoring system. Embryonic growth and development in the absence of maternal influences allows for the study of the direct action of agents or their metabolites on the embryo. The use of both rodent and rabbit WEC together is a powerful strategy with which to investigate species-specific vulnerabilities to specific agents.

Cumulative live birth rates and perinatal outcomes with the use of time-lapse imaging incubators for embryo culture: a retrospective cohort study of 1882 ART cycles.

OBJECTIVE: Comparison of live birth rates and the perinatal outcomes after fresh and frozen embryo transfer between time-lapse imaging (TLI) and standard culture (SC) incubators. DESIGN: Retrospective cohort study. SETTING: A single tertiary level IVF unit. POPULATION: Women undergoing IVF between January 2014 and October 2015. METHODS: Comparison was done between 1064 IVF cycles using TLI (TLI cycles) and 818 IVF cycles using SC (SC cycles). MAIN OUTCOME MEASURES: Cumulative live birth rate per oocyte retrieval and perinatal outcomes including birthweight, gestational age, preterm birth (PTB) (<37 weeks), early preterm birth (PTB; <32 weeks), low birthweight (LBW; <2500 g), very LBW (<1500 g) and macrosomia (>4500 g). RESULTS: The fresh embryo transfer live birth rate was noted to be higher for TLI cycles [TLI 36.8 versus SC 33.9%, adjusted odds ratio (aOR) 1.28, 95% CI 1.05-1.57], but the frozen embryo transfer live birth rates were not significantly different. The mean birthweight was higher in the TLI group after both fresh [adjusted mean difference (aMD) 174.78 g, 95% CI 64.80-284.77] and frozen embryo transfers (aMD 175.91 g, 95% CI 16.98-334.84). After a fresh embryo transfer, there was a lower risk of early PTB and very LBW in the TLI group. Among frozen embryo transfers, there was a lower risk of early PTB and LBW in the TLI group. CONCLUSIONS: TLI incubators are associated with improved perinatal outcomes and higher mean birthweight after fresh and frozen embryo transfer. TWEETABLE ABSTRACT: Time-lapse imaging incubators in IVF improve perinatal outcomes after both fresh and frozen embryo transfers.

[Method validation of a critical parameter in human embryos culture: culture media pH]. / Validation de la mesure d'un paramètre critique en culture d'embryons humains : le pH.

In vitro human embryos culture depends largely on the atmospheric conditions within the incubators of the laboratory. The pH of culture media, an indirect reflection of the CO2 content inside these incubators, is a critical parameter. Collaboration between the biochemistry and reproductive biology departments enabled the automated measurement of the pH in the culture medium on a blood gas analyzer. This method has been validated and evaluated. It is applicable in all laboratories whatever the medium and the conditions of culture. It allows strict monitoring of this parameter for the optimization of the culture conditions necessary to improve the results of in vitro fertilization attempts.

Considerations Regarding Embryo Culture Conditions: From Media to Epigenetics.

There are numerous reports on embryo culture media and conditions in the laboratory, as the subject is multifaceted and complex, reflecting the variation in practice. In this scoping review, we attempt to approach the topic of culture media and conditions from the practitioners' perspective aiming to highlight, in a comprehensive fashion, important aspects regarding the options available, introduce points of debate and controversy, while maintaining the viewpoint of the practicing embryologist's concerns.

Microinjection of Exogenous Nucleic Acids into Eggs: Ciona Species.

Microinjection is a common technique used to deliver nucleic acids into eggs and embryos in Ciona species. There are three Ciona species that are commonly used for research-Ciona intestinalis type A (C. robusta), C. intestinalis type B (C. intestinalis), and C. savignyi. Here, we present the microinjection methods using eggs and embryos of C. intestinalis type A and C. savignyi; however, our methods would also be applicable to eggs and embryos of C. intestinalis type B. Microinjection is a classical and widely used delivery method, which involves the use of a glass micropipette, a hollow glass needle with a microscopic tip, to inject nucleic acids into eggs and embryos under a stereo microscope. The required amount of nucleic acids is much smaller for microinjection than for electroporation, another delivery method. Proteins, and other chemicals, such as fluorescent dye, can be introduced with nucleic acids using a microinjection.

Practical Guide for Ascidian Microinjection: Phallusia mammillata.

Phallusia mammillata has recently emerged as a new ascidian model. Its unique characteristics, including the optical transparency of eggs and embryos and efficient translation of exogenously introduced mRNA in eggs, make the Phallusia system suitable for fluorescent protein (FP)-based imaging approaches. In addition, genomic and transcriptomic resources are readily available for this ascidian species, facilitating functional gene studies. Microinjection is probably the most versatile technique for introducing exogenous molecules such as plasmids, mRNAs, and proteins into ascidian eggs/embryos. However, it is not practiced widely within the community; presumably, because the system is rather laborious to set up and it requires practice. Here, we describe in as much detail as possible two microinjection methods that we use daily in the laboratory: one based on an inverted microscope and the other on a stereomicroscope. Along the stepwise description of system setup and injection procedure, we provide practical tips in the hope that this chapter might be a useful guide for introducing or improving a microinjection setup.

Microinjection of Exogenous DNA into Eggs of Halocynthia roretzi.

Exogenous gene expression assays during development, including reporters under the control of 5' upstream enhancer regions of genes, constitute a powerful technique for understanding the mechanisms of tissue-specific gene expression regulation and determining the characteristics, behaviors, and functions of cells that express these genes. The simple marine chordate Halocynthia roretzi has been used for these transgenic analyses for a long time and is an excellent model system for such studies, especially in comparative analyses with other ascidians. In this study, I describe simple methods for microinjecting H. roretzi eggs with exogenous DNA, such as a promoter construct consisting of a 5' upstream region and a reporter gene, which are prerequisites for transgenic analyses. I also describe basic knowledge regarding this ascidian species, providing reasons why it is an ideal subject for developmental biology studies.

Randomized controlled trial comparing embryo culture in two incubator systems: G185 K-System versus EmbryoScope.

OBJECTIVE: To study whether the closed culture system, as compared with a benchtop incubator with similar culture conditions, has a positive impact on intracytoplasmic sperm injection (ICSI) outcomes. DESIGN: Randomized controlled trial. SETTING: University hospital. PATIENT(S): A total of 386 patients undergoing ICSI cycles with at least six mature oocytes were randomized. INTERVENTION(S): Of these patients, 195 were assigned to the group with culture in a time-lapse imaging (TLI) system (EmbryoScope) and 191 to the group with culture in the G185 K-System (G185). MAIN OUTCOME MEASURE(S): Rate of implantation (primary endpoint) and embryo morphology grade. RESULT(S): No significant differences were found in the implantation rates. The proportion of high-grade embryos on day 2 was significantly higher in the TLI group compared with the G185 group (40.4% vs. 35.2%). The impact of the incubator on embryo morphology remained significant in multivariate analysis, which took into account the woman's age, the rank of attempt, and the smoking status (TLI vs. G185: odds ratio = 1.27; 95% confidence interval, [1.04-1.55]). No difference was found in the mean number of frozen embryos, even though the total proportion of frozen embryos was significantly higher in the TLI group than in the G185 group (29.5% vs. 24.8%). CONCLUSION(S): No difference in implantation rate was found between the two incubators for fresh cycles. It remains to be determined whether the observed differences in embryo morphology and the total number of embryos cryopreserved would translate into higher cumulative outcomes with subsequent frozen embryo transfers. CLINICAL TRIAL REGISTRATION NO: NCT02722252.

Comparison of the development of human embryos cultured in either an EmbryoScope or benchtop incubator.

PURPOSE: In this current study, our main goal was to establish that EmbryoScope incubation environment is comparable to standard incubation. METHODS: The development of sibling human zygotes was compared after culture in either a benchtop incubator (SI) or an EmbryoScope time-lapse incubator (ES). Between May 2015 to April 2016, a total of 581 normally fertilized 2PN, pronuclear-stage embryos, from 47 patients were allocated to culture in either a benchtop incubator (SI) or an EmbryoScope incubator (ES). RESULTS: The development of embryos to cleavage (up to day 3) and blastocyst stages (day 5/6) was compared between the two different incubators. The proportion of good quality embryos was higher in the ES group compared to the SI on day 2 (66.8 vs. 50.5%, P = 0.014) and on day 3 (75.1 vs. 56.0%, P = 0.006). Those differences were statistically significant. A higher proportion of embryos developed to good quality blastocysts when cultured in the EmbryoScope compared to the benchtop (49.4 vs. 42.0%, P = 0.24), but this was not significant. Finally, no significant differences were noted with the proportion of blastocysts chosen for cryopreservation on day 5/6 in the two incubators. CONCLUSIONS: The findings support the view that the EmbryoScope incubator supports at least equivalent in vitro development of human embryos compared to other standard incubation methods and may promote improved development during early cleavage stages.

Humid versus dry incubator: a prospective, randomized, controlled trial.

OBJECTIVE: To evaluate the efficacy of a dry versus humidified incubator on human embryo development ex vivo. DESIGN: Prospective, double-blind, randomized, controlled trial. SETTING: Private fertility centers. PATIENT(S): A total of 297 women undergoing in vitro fertilization randomized into two groups. INTERVENTION(S): From days 0 to day 5 or 6 of culture, intervention group embryos exposed to dry culture and control group embryos exposed to humidified culture. MAIN OUTCOME MEASURE(S): Subsequent ongoing pregnancy rate. RESULT(S): After transfer of embryos, there were statistically significantly lower rates of clinical and ongoing pregnancy in the dry culture arm than in the humidified culture arm (odds ratio [OR] 0.57; 95% confidence interval [CI], 0.36-0.91; versus OR 0.54; 95% CI, 0.34-0.85). On day 3 of culture, embryo quality and compaction were lower in the dry culture group (OR 0.38; 95% CI, 0.32-0.45) than in the group exposed to humidified culture (OR 0.23; 95% CI, 0.19-0.27). On day 5 of culture, embryos in dry culture had a lower rate of blastocyst formation (OR 0.39; 95% CI, 0.33-0.46), quality (OR 0.34; 95% CI, 0.29-0.40), and cryopreservation (OR 0.41; 95% CI, 0.35-0.48). CONCLUSION(S): In this study, human embryos cultivated ex vivo in a dry incubator had statistically significantly decreased implantation and clinical and ongoing pregnancy rates. Our findings indicate the need for larger multicenter, randomized, controlled trials. CLINICAL TRIAL REGISTRATION NUMBER: NCT01695096.

Pregnancy rates of day 4 and day 5 embryos after culture in an integrated time-lapse incubator.

BACKGROUND: The aim of this study was to compare pregnancy rates in patients undergoing IVF/ICSI with embryo transfer after 4 and 5 days of culture in a closed incubation system with integrated time-lapse imaging. METHODS: Out of n = 2207 in vitro fertilization (IVF)/ intracytoplasmic sperm injection (ICSI) cycles performed between January 2011 and April 2016 at a tertiary referral university hospital, a total of n = 599 IVF/ICSI cycles with prolonged embryo culture in an integrated time-lapse system (EmbryoScope© (Vitrolife)) until day 4 or 5 were retrospectively analyzed with regard to embryo morphology and pregnancy rates. RESULTS: A transfer on day 5 compared to a transfer on day 4 did not result in higher implantation and clinical pregnancy rates (IR 29.4% on day 4 versus 33.0% on day 5, p = 0.310; CPR 45.2% on day 4 versus 45.7% on day 5, p = 1.0). The percentage of ideal embryos transferred on day 4 was comparable to the rate of ideal embryos transferred on day 5 (41.6% versus 44.1%, p = 0.508). However, on day 4 a significantly higher number of embryos was transferred (1.92 on day 4 versus 1.84 on day 5, p = 0.023), which did not result in higher rates of multiple pregnancies. CONCLUSIONS: Pregnancy rates in IVF/ICSI cycles with integrated time-lapse incubation and transfer on day 4 and 5 are comparable. This finding provides the clinician, IVF laboratory and patient with more flexibility. TRIAL REGISTRATION: This study was retrospectively registered by the local ethics committee of the University of Heidelberg on December 19, 2016 (registration number S-649/2016).

Microfluidic analysis of oocyte and embryo biomechanical properties to improve outcomes in assisted reproductive technologies.

Measurement of oocyte and embryo biomechanical properties has recently emerged as an exciting new approach to obtain a quantitative, objective estimate of developmental potential. However, many traditional methods for probing cell mechanical properties are time consuming, labor intensive and require expensive equipment. Microfluidic technology is currently making its way into many aspects of assisted reproductive technologies (ART), and is particularly well suited to measure embryo biomechanics due to the potential for robust, automated single-cell analysis at a low cost. This review will highlight microfluidic approaches to measure oocyte and embryo mechanics along with their ability to predict developmental potential and find practical application in the clinic. Although these new devices must be extensively validated before they can be integrated into the existing clinical workflow, they could eventually be used to constantly monitor oocyte and embryo developmental progress and enable more optimal decision making in ART.