Bed rest after embryo transfer negatively affects in vitro fertilization: a randomized controlled clinical trial.

Objective To evaluate the influence of 10 minutes of bed rest after ET on the achievement of a live-born infant (LBI) in patients undergoing IVF treatment with oocyte donation (OD). Design Prospective, randomized, parallel assignment, controlled trial. Setting Private IVF center. Patient(s) A total of 240 patients undergoing a first IVF cycle with OD in our center. Intervention(s) Ten minutes of bed rest after ET or no bed rest, that is, allowing patients to ambulate immediately after the ET. Main Outcome Measure(s) The primary outcome was LBI rate per randomized patient. Secondary outcomes were implantation rate and biochemical and clinical miscarriage rates. Result(s) LBI rates (56.7% vs.…

Vitrification of human mature oocytes in clinical practice.

Oocyte cryopreservation has long been the focus of unsuccessful efforts to perfect its clinical application. Lately, vitrification has been shown to provide high degrees of success by different research groups. This review attempts to address the efficiency of oocyte vitrification in clinical practice through an analysis of reports of IVF cycles in which embryo transfers have been conducted with vitrified metaphase-II human oocytes.

Vitrification of human oocytes.

In recent years, growing evidence for the safety and efficiency of oocyte vitrification has made this technique be increasingly proposed for fertility preservation (FP). The populations who could benefit from FP include oncological patients who need the option to preserve their gametes before undergoing potential sterilizing treatment, patients with non-oncologic conditions requiring gonadotoxic chemotherapy and women who wish to delay their motherhood for a variety of reasons. By vitrifying oocytes, women have the chance to conceive in the future, have their own genetic offspring and maintain their reproductive autonomy. This review focuses on describing current knowledge on oocyte vitrifi…

Oocyte vitrification versus ovarian cortex transplantation in fertility preservation for adult women undergoing gonadotoxic treatments: a prospective cohort study

Objective To compare the efficacy of oocyte vitrification (OV) with that of ovarian cortex cryopreservation and transplantation (OCT) in women undergoing gonadotoxic treatments. Design Prospective observational cohort study. Setting Not applicable. Patient(s) Candidates for chemo-/radiotherapy who joined our fertility preservation (FP) program were included in this study between 2005 and 2015. One cohort included 1,024 patients undergoing OV; the other cohort included 800 patients undergoing OCT. Intervention(s) OV using the cryotop device and OCT using a slow freezing protocol. Main Outcome Measure(s) Live-birth rate (LBR) and clinical pregnancy rate (CPR). Result(s) Basal antimullerian ho…

Embryo culture: can we perform better than nature?

Culture of preimplantation-stage embryos has always been a key element of laboratory embryology and has contributed substantially to the success of many assisted reproduction procedures. During the past decade, its importance has increased as extended in-vitro embryo culture and single blastocyst transfer have become indispensable parts of the approach to decreasing the chance of multiple pregnancy while preserving the overall efficiency of the treatment. However, in spite of the scientific and commercial challenge stimulating research worldwide to optimize embryo culture conditions, a consensus is missing even in the basic principles, including composition and exchange of media, the requir…

New Tools for Embryo Selection: Comprehensive Chromosome Screening by Array Comparative Genomic Hybridization

The objective of this study was to evaluate the usefulness of comprehensive chromosome screening (CCS) using array comparative genomic hybridization (aCGH). The study included 1420 CCS cycles for recurrent miscarriage (n=203); repetitive implantation failure (n=188); severe male factor (n=116); previous trisomic pregnancy (n=33); and advanced maternal age (n=880). CCS was performed in cycles with fresh oocytes and embryos (n=774); mixed cycles with fresh and vitrified oocytes (n=320); mixed cycles with fresh and vitrified day-2 embryos (n=235); and mixed cycles with fresh and vitrified day-3 embryos (n=91). Day-3 embryo biopsy was performed and analyzed by aCGH followed by day-5 embryo tran…

Comparison between storage of vitrified oocytes by cryotop method in liquid nitrogen vs. vapour phase of liquid nitrogen tanks

Use of cryo-banked oocytes in an ovum donation programme: a prospective, randomized, controlled, clinical trial

background: An efficient oocyte cryopreservation method is mandatory to establish a successful egg-banking programme. Although there are increasing reports showing good clinical outcomes after oocyte cryopreservation, there is still a lack of large controlled studies evaluating the effectiveness of oocyte cryo-banking. In this study, we aimed to compare the outcome of vitrified-banked oocytes with the gold standard procedure of employing fresh oocytes. methods: A randomized, prospective, triple-blind, single-centre, parallel-group controlled-clinical trial (NCT00785993), including 600 recipients (a ¼ 0.05 and power of 80% for sample-size calculation) selected among 1032 eligible patients fr…

Effect of oocyte morphology on post-warming survival and embryo development in vitrified autologous oocytes.

Abstract Research question Does the presence of dysmorphisms affect post-warming survival and embryo development in vitrified autologous oocytes? Design A retrospective study comparing post-warming survival, fertilization and embryo development between morphologically normal (n = 269) and dysmorphic oocytes (n = 147). Results The survival rate was 81.4% in the morphologically normal oocytes and 87.1% in the dysmorphic oocyte group (OR 1.53; 95% CI 0.86 to 2.72). The fertilization rate was 69.9 versus 66.4% (OR 0.85; 95% CI 0.53 to 1.36), the proportion of good-quality embryos on day 3 was 30.3% versus 32.0% (OR 1.08; 95% CI 0.59 to 1.97) and the blastocyst formation rate was 54.5% versus 60…

Storage of human oocytes in the vapor phase of nitrogen

Objective To evaluate the effectiveness of long-term vapor-phase nitrogen storage of vitrified human oocytes as a strategy for preventing the risk of cross-contamination due to direct contact with the liquid nitrogen (LN). Design Prospective randomized study. Setting Private infertility center, IVI, Valencia. Patient(s) Oocyte donors (n = 44) and recipients (n = 46). Intervention(s) Vitrification by the Cryotop method. Storage of vitrified oocytes in a vapor-phase nitrogen storage freezer and a traditional LN storage tank. Donation of the surviving oocytes and evaluation of fertilization, embryo development, and clinical results. Main Outcome Measure(s) Survival, fertilization, and cleavage…

Vitrification in assisted reproduction: myths, mistakes, disbeliefs and confusion

The purpose of this work is to update embryologists and clinicians on different approaches in human oocyte and embryo cryopreservation, by clarifying some misunderstandings and explaining the underlying reasons for controversial opinions. The work is based on literature review and critical analysis of published papers or conference abstracts during the last 24 years, with special focus on the last 3 years. Due to the latest advancements in techniques, cryopreservation now offers new perspectives along with solutions to many demanding problems, and has developed from a backup procedure to a successful alternative that is an indispensable constituent of assisted reproductive techniques. Howev…

Effect of different cryopreservation protocols on the metaphase II spindle in human oocytes.

The aim of this study was to evaluate the impact of different cryopreservation protocols on the repolymerization of metaphase (M)II spindles in human oocytes. Fresh aspirated donor oocytes were cryopreserved 3–4 h after retrieval using four different protocols: slow freezing using 1.5 mol/l 1,2-propanediol (PROH) + 0.2 mol/l sucrose (n = 36); 1.5 mol/l PROH + 0.3 mol/l sucrose (n = 34); 1.5 mol/l PROH + 0.3 mol/l sucrose with Na + depleted–choline replaced media (n = 27), and vitrification by the Cryotip method (n = 23). The control group comprised 34 fresh oocytes. Three hours after thawing, surviving and control oocytes were fixed for meiotic spindle/chromatin assessment. Survival rates w…

Comparison of concomitant outcome achieved with fresh and cryopreserved donor oocytes vitrified by the Cryotop method

Objective To evaluate the outcome of oocyte vitrification using the Cryotop method, observed in an egg donation program by simultaneously evaluating embryos derived from vitrified and fresh oocytes coming from the same stimulated cycle. Design Cohort prospective randomized study. Setting Instituto Valenciano de Infertilidad (IVI) Valencia, Spain. Patient(s) Thirty oocyte donors and 30 recipients with informed consents. Intervention(s) Vitrification by the Cryotop method. Warming 1 hour after vitrification. Microinjection of surviving MII and fresh oocytes, evaluation of fertilization, embryo development, and clinical results. Main Outcome Measure(s) Survival, fertilization, and cleavage rat…

Effect of vitrification on human oocytes: a metabolic profiling study.

Objective To evaluate the effect of oocyte vitrification in the metabolomic profile of embryos developed from vitrified and fresh oocytes in our ovum donation program. Design Analysis of the metabolic profiles of spent culture medium samples corresponding to embryos developed from vitrified and fresh oocytes. Setting In vitro fertilization (IVF) unit/metabolomic facility. Patient(s) Oocyte donors between the ages of 18 and 35 years. Intervention(s) Metabolomic profile liquid chromatography coupled with mass spectrometry (LC-MS) of spent media samples. Main Outcome Measure(s) Identification of spent media components and metabolites present and absent in vitrified and fresh day-3 embryos. Res…

Analysis of the morphological dynamics of blastocysts after vitrification/warming: defining new predictive variables of implantation

Objective To describe the morphological dynamics of vitrified/warmed blastocysts and to identify quantitative morphological variables related to implantation. Subsequently, by using the most predictive parameters, to develop a hierarchical model by subdividing vitrified/warmed blastocysts into categories with different implantation potentials. Design Observational, retrospective, cohort study. Setting University-affiliated private IVF center. Patient(s) The study included 429 vitrified/warmed blastocysts with known implantation data, which were evaluated by time-lapse imaging. Blastocysts were routinely placed in EmbryoScope (Vitrolife) immediately after warming until transfer. Intervention…

Twins born after transplantation of ovarian cortical tissue and oocyte vitrification

Objective To present a combination of ovarian tissue and oocyte cryopreservation as an effective strategy for achieving pregnancy in a breast cancer patient. Design Case report. Setting Tertiary care university-affiliated hospital, tissue bank, and infertility clinic. Patient(s) A 36-year-old patient diagnosed with atypical medullar breast cancer and negative for estrogen, P, and HER2 receptors underwent ovarian tissue cryopreservation before receiving chemotherapy and radiotherapy. Intervention(s) Laparoscopic ovarian cortex extraction, ovarian tissue cryopreservation, ovarian tissue thawing and transplantation, controlled ovarian stimulation (COS), oocyte retrieval, vitrification and IVF,…

New options in assisted reproduction technology: the Cryotop method of oocyte vitrification

The Cryotop vitrification method has been shown to be a very useful tool for oocyte cryopreservation, giving excellent results regarding survival and clinical outcome. There are several clinical situations in which oocyte cryopreservation provides solutions that have not been available to date. This report describes three of these situations: (i) a low-responder patient who needed a single gene diagnosis due to the presence of a genetic disease; (ii) a patient undergoing endometrial bleeding on the day of oocyte retrieval who was also affected by a genetic disorder; and (iii) a patient who failed to become pregnant after the donation of vitrified oocytes and subsequently had the re-vitrifie…

Prediction of embryo survival and live birth rates after cryotransfers of vitrified blastocysts

Which pre-vitrification parameters are the most predictive of survival and live birth in vitrified-warmed blastocyst transfer cycles?A retrospective study including 11,936 warmed blastocysts. Pre-vitrification morphological parameters analysed for blastocysts included day of vitrification; blastocyst expansion degree; trophoectoderm grade (A, B and C); and inner cell mass grade (A, B and C). Univariate and multivariate generalized estimating equations models were used to analyse survival, clinical pregnancy and live birth rate. A stepwise regression analysis was conducted to select and classify by order which outcomes were the most predictive.The odds of survival increased almost twice for …

Obstetric and perinatal outcome of babies born from vitrified oocytes.

Objective To assess outcomes after oocyte vitrification on obstetric and perinatal outcomes compared with those achieved with fresh oocytes. Design Retrospective cohort study. Setting Private university-affiliated IVF center. Patient(s) Children born after use of vitrified oocytes (1,027 from 804 pregnancies) and fresh oocytes (1,224 from 996 pregnancies). Singleton and multiples pregnancies from own and donated ova were included. Intervention(s) Oocyte vitrification by the Cryotop method. Main Outcome Measure(s) Pregnancy, delivery, and neonatal outcomes. Result(s) Vitrification had no clinically relevant adverse effects on obstetric and perinatal outcomes after adjusting for potential con…

Effect of oocyte vitrification on embryo quality: time-lapse analysis and morphokinetic evaluation.

To analyze whether oocyte vitrification may affect subsequent embryo development from a morphokinetic standpoint by means of time-lapse imaging.Observational cohort study.University-affiliated private IVF center.Ovum donation cycles conducted with the use of vitrified (n = 631 cycles; n = 3,794 embryos) or fresh oocytes (n = 1,359 cycles; n = 9,935 embryos) over 2 years.None.Embryo development was analyzed in a time-lapse imaging incubator. The studied variables included time to 2 cells (t2), 3 cells (t3), 4 cells (t4), 5 cells (t5), morula (tM), and cavitated, early, and hatching blastocyst (tB, tEB, tHB) as well as 2nd cell cycle duration (cc2 = t3 - t2). All of the embryos were classifie…

Number needed to freeze: cumulative live birth rate after fertility preservation in women with endometriosis

Research question: How does the number of oocytes used affect the cumulative live birth rate in endometriosis patients who had their oocytes vitrified for fertility preservation (FP)? Design: Retrospective observational study including data from 485 women with endometriosis who underwent FP from January 2007 to July 2018. Survival curves and Kaplan-Meier plots were used to analyse the cumulative live birth rate (CLBR) according to the number of vitrified oocytes used. Data were stratified according to age, stage of the disease and ovarian surgery prior to FP (operated vs. non-operated). Endometriosis curves were compared to plots developed using elective fertility preservation (EFP) patient…