RESUMEN
In the last four decades, the assisted reproductive technology (ART) field has witnessed advances, resulting in improving pregnancy rates and diminishing complications, in particular reduced incidence of multiple births. These improvements are secondary to advanced knowledge on embryonic physiology and metabolism, resulting in the ability to design new and improved culture conditions. Indeed, the incubator represents only a surrogate of the oviduct and uterus, and the culture conditions are only imitating the physiological environment of the female reproductive tract. In vivo, the embryo travels through a dynamic and changing environment from the oviduct to the uterus, while in vitro, the embryo is cultured in a static fashion. Importantly, while culture media play a critical role in optimising embryo development, a large host of additional factors are equally important. Additional potential variables, including but not limited to pH, temperature, osmolality, gas concentrations and light exposure need to be carefully controlled to prevent stress and permit optimal implantation potential. This manuscript will provide an overview of how different current culture conditions may affect oocyte and embryo viability with particular focus on human literature.
Asunto(s)
Implantación del Embrión , Técnicas Reproductivas Asistidas , Embarazo , Humanos , Femenino , Implantación del Embrión/fisiología , Desarrollo Embrionario/genética , Embrión de Mamíferos , Medios de Cultivo , Técnicas de Cultivo de Embriones/métodos , Fertilización In Vitro/métodosRESUMEN
RESEARCH QUESTION: Does type of culture medium used influence obstetric and perinatal outcomes after vitrified-warmed single blastocyst transfers? DESIGN: Retrospective cohort study involving singletons after vitrified-warmed single blastocyst embryo transfers, using embryos cultured in either Irvine Continuous Single Culture medium (CSC) or Vitrolife G5TM PLUS medium culture system between 2013 and 2020. RESULTS: A total of 2475 women who had singleton deliveries were included for final analysis: 1478 had embryos cultured in CSC and 997 had embryos cultured in G5TM PLUS medium. Birth outcomes, including preterm birth, mean birth weight, gestational age- and sex-adjusted birth weight (Z-scores), rates of large-for-gestational-age, small-for-gestational-age, low birth weight and macrosomia, and the distribution of newborn gender did not differ significantly between groups in crude and adjusted analyses. Women whose embryos were cultured in G5TM PLUS frequently suffered from pregnancy-induced hypertensive disorders compared with those who had embryos cultured in CSC (4.7% versus 3.0%; Pâ¯=â¯0.031). This difference was no longer significant after adjusting for several key confounders (adjusted odds ratio 1.49, 95% CI 0.94 to 2.38, Pâ¯=â¯0.087). Other obstetric complications, including gestational diabetes mellitus, preterm premature rupture of membranes, abnormal placentation, postpartum haemorrhage and the mode of delivery were all similar between the two groups. CONCLUSIONS: The present study adds new information to the current evidence by suggesting that the embryo culture medium does not affect birth outcomes and obstetric complications when comparison is limited to Irvine CSC and Vitrolife G5TM PLUS in vitrified-warmed single blastocyst transfer cycles.
Asunto(s)
Complicaciones del Embarazo , Nacimiento Prematuro , Embarazo , Recién Nacido , Humanos , Femenino , Peso al Nacer , Criopreservación , Estudios Retrospectivos , Vitrificación , Transferencia de Embrión , Medios de Cultivo , BlastocistoRESUMEN
Recently, infertility has become one of the most important endemic conditions, affecting approximately 15-20 % of couples worldwide. Among others, the careerist lifestyle, the increasing maternal age and the parallel increment in the aneuploidy rate of embryos play a crucial role in this phenomenon. In this study, embryological parameters and pregnancy outcomes were investigated in IVF cycles using either sequential embryo culture or a single step culture system. By sequential media, oocytes/embryos are needlessly exposed to the potentially negative effects of light exposure, temperature decrement and altered oxygen tension. In comparison with sequential media, single step media induced 1.28, 1.21 and 1.21-fold increments in implantation, biochemical pregnancy and clinical pregnancy rates, respectively. Pregnancy outcomes showed strong maternal age-dependency, so the difference between the two investigated culture systems was equalized by the increasing maternal ages (35-44 years) and the supposed incidence of embryo aneuploidy. Nevertheless, the significant enlargements in the outcomes of the younger ages (25-34) induced by the single step cultures suggest that, beside the resultant maternal aneuploidy, aneuploidy (reduced pregnancy rates) may evolve from exposure to the mentioned environmental stress factors.
Asunto(s)
Técnicas de Cultivo de Embriones/métodos , Resultado del Embarazo , Inyecciones de Esperma Intracitoplasmáticas/métodos , Adulto , Aneuploidia , Medios de Cultivo , Transferencia de Embrión/métodos , Femenino , Humanos , Luz , Edad Materna , Oxígeno , Embarazo , Índice de Embarazo , TemperaturaRESUMEN
In vitro fertilization (IVF) and embryo culture in the human is a unique endeavor. Human assisted reproductive technology (ART) is practiced clinically to treat infertility. Due to the obvious ethical considerations of ART as applied to human medicine, only rarely is embryo culture undertaken for research purposes. As most IVF clinics are for profit businesses, a robust industry has developed to supply embryologists with quality control-tested media, equipment, and supplies necessary to support human IVF laboratory operation. Moreover, commercial items are preferred for efficiency and consistency, and strict quality control is required by accrediting organizations. As such, very little manual formulation or preparation of culture medium is typically required. Although human embryo culture is performed clinically, there is a surprising degree of variability in the details of the techniques used. In this chapter, we describe state-of-the-art procedures for gamete collection, in vitro fertilization, embryo culture, and embryo transfer that result in excellent blastocyst development and pregnancy rates for patients seeking treatment for infertility.
Asunto(s)
Blastocisto/metabolismo , Técnicas de Cultivo de Embriones/métodos , Transferencia de Embrión/métodos , Fertilización In Vitro/métodos , Blastocisto/citología , Femenino , Humanos , EmbarazoRESUMEN
PURPOSE: To assess whether continuous embryo culture involves better embryological and/or clinical outcomes than sequential. METHODS: Prospective study at a private IVF center. All consecutive IVF cycles (September 2013-2015) fulfilling the inclusion criteria underwent embryo culture in either Continuous-Single-Culture-Media (CSCM, n = 972) or sequential media (Quinn's Advantage, n = 514), respectively. ICSI, blastocyst culture in either standard (MINC) or undisturbed (Embryoscope) incubation, transfer (until September 2016), and pregnancy follow-up (until September 2017) were performed. When aneuploidy testing was required, trophectoderm biopsy and qPCR were performed. Sub-analyses and logistic regression corrected for confounders were performed. The primary outcomes were overall blastocyst rate per oocyte and mean blastocyst rate per cycle. The sample size was defined to reach 95 and 80% statistical power for the former and the latter outcome, respectively. Secondary outcomes were euploidy (if assessed), cumulative delivery rates, gestational age, and birthweight. RESULTS: Continuous embryo culture resulted into a higher overall blastocyst rate per inseminated oocyte than sequential (n = 2211/5841, 37.9% vs. 1073/3216, 33.4%; p < 0.01), confirmed also from a cycle-based analysis (mean blastocyst rate: 38.7% ± 29.7% vs. 34.3% ± 29.4%; p = 0.01). The continuous media (OR = 1.23), the undisturbed incubation system (OR = 1.22), the maternal age (OR = 0.92), and the sperm factor (OR = 0.85) were outlined as positive predictors of blastulation. However, the cumulative delivery rates per ended cycle (i.e., delivery achieved or no blastocyst produced or left; > 90%) were comparable in the two groups (n = 244/903, 27.0% vs. 129/475, 27.2%). The neonatal outcomes were similar. CONCLUSIONS: Continuous culture involves better embryological but similar clinical outcomes than sequential. This large prospective study supports the absence of clinical disparity among the two approaches.
Asunto(s)
Técnicas de Cultivo de Embriones/métodos , Fertilización In Vitro/métodos , Aneuploidia , Blastocisto/fisiología , Medios de Cultivo/metabolismo , Implantación del Embrión/fisiología , Transferencia de Embrión/métodos , Femenino , Humanos , Edad Materna , Oocitos/fisiología , Embarazo , Índice de Embarazo , Estudios Prospectivos , Inyecciones de Esperma Intracitoplasmáticas/métodosRESUMEN
Oxidation-reduction potential describes the balance between the oxidants and antioxidants in fluids including semen. Various artificial culture media are used in andrology and IVF laboratories for sperm preparation and to support the development of fertilized oocytes under in vitro conditions. The composition and conditions of these media are vital for optimal functioning of the gametes. Currently, there are no data on the status of redox potential of sperm processing and assisted reproduction media. The purpose of this study was to compare the oxidation-reduction potential values of the different media and to calibrate the oxidation-reduction potential values of the sperm wash medium using oxidative stress inducer cumene hydroperoxide and antioxidant ascorbic acid. Redox potential was measured in 10 different media ranging from sperm wash media, freezing media and assisted reproductive technology one-step medium to sequential media. Oxidation-reduction potential values of the sequential culture medium and one-step culture medium were lower and significantly different (p < 0.05) from the sperm wash media. Calibration of the sperm wash media using the oxidant cumene hydroperoxide and antioxidant ascorbic acid demonstrated that oxidation-reduction potential and the concentration of oxidant or antioxidant are logarithmically dependent. This study highlights the importance of calibrating the oxidation-reduction potential levels of the sperm wash media in order to utilize it as a reference value to identify the physiological range of oxidation-reduction potential that does not have any adverse effect on normal physiological sperm function.
Asunto(s)
Medios de Cultivo/química , Técnicas Reproductivas Asistidas , Semen/fisiología , Ácido Ascórbico/química , Derivados del Benceno/química , Calibración , Criopreservación , Medios de Cultivo/farmacología , Femenino , Humanos , Concentración de Iones de Hidrógeno , Masculino , Oxidación-Reducción , Proyectos Piloto , Valores de Referencia , Semen/efectos de los fármacos , Preservación de Semen , Espermatozoides/fisiologíaRESUMEN
The aim of the present study was to compare blastocyst formation rates after embryo culture in a single medium (Global) as compared to sequential media (ISM1/BlastAssist). In this prospective trial with sibling oocytes, 542 metaphase II (ΜΙΙ) oocytes from 31 women were randomly and equally divided to be fertilized and cultured to the blastocyst stage in either sequential media (ISM1/BlastAssist; n = 271 MII oocytes) or a single medium (Global; n = 271 MII oocytes). In both groups, embryos were cultured in an interrupted fashion with media changes on day 3. Embryo transfer was performed on day 5. Blastocyst formation rates on day 5 (61.7% ± 19.9% vs 37.0% ± 25.5%, P < .001) were significantly higher following culture in Global as compared to ISM1/BlastAssist, respectively. Fertilization rates, cleavage rates, and percentage of good quality embryos on day 3 were similar between Global and ISM1/BlastAssist, respectively. The percentages of good quality blastocysts (63.0% ± 24.8% vs 32.1% ± 37.2%, P < .001), blastocysts selected for transfer (27.8% ± 19.2% vs 11.1% ± 14.4%, P = .005), and utilization rates (62.5% ± 24.8% vs 39.0% ± 25.2%, P < .001) were significantly higher in Global as compared to ISM1/BlastAssist, respectively. In conclusion, culture in Global was associated with higher blastocyst formation rates compared to ISM1/BlastAssist, suggesting that the single medium may provide better support to the developing embryo.
Asunto(s)
Medios de Cultivo , Técnicas de Cultivo de Embriones/métodos , Desarrollo Embrionario/fisiología , Adulto , Blastocisto , Transferencia de Embrión , Femenino , Humanos , Estudios Prospectivos , HermanosRESUMEN
OBJECTIVE: To study whether a culture medium that allows undisturbed culture supports human embryo development to the blastocyst stage equivalently to a well-established sequential media. DESIGN: Randomized, double-blinded sibling trial. SETTING: Independent in vitro fertilization (IVF) clinics. PATIENT(S): One hundred twenty-eight patients, with 1,356 zygotes randomized into two study arms. INTERVENTION(S): Embryos randomly allocated into two study arms to compare embryo development on a time-lapse system using a single-step medium or sequential media. MAIN OUTCOME MEASURE(S): Percentage of good-quality blastocysts on day 5. RESULT(S): Percentage of day 5 good-quality blastocysts was 21.1% (standard deviation [SD] ± 21.6%) and 22.2% (SD ± 22.1%) in the single-step time-lapse medium (G-TL) and the sequential media (G-1/G-2) groups, respectively. The mean difference (-1.2; 95% CI, -6.0; 3.6) between the two media systems for the primary end point was less than the noninferiority margin of -8%. There was a statistically significantly lower number of good-quality embryos on day 3 in the G-TL group [50.7% (SD ± 30.6%) vs. 60.8% (SD ± 30.7%)]. Four out of the 11 measured morphokinetic parameters were statistically significantly different for the two media used. The mean levels of ammonium concentration in the media at the end of the culture period was statistically significantly lower in the G-TL group as compared with the G-2 group. CONCLUSION(S): We have shown that a single-step culture medium supports blastocyst development equivalently to established sequential media. The ammonium concentrations were lower in the single-step media, and the measured morphokinetic parameters were modified somewhat. CLINICAL TRIAL REGISTRATION NUMBER: NCT01939626.