Usefulness of random-start progestin-primed ovarian stimulation for fertility preservation

Background Progestin-primed ovarian stimulation (PPOS) has been used in infertility cases in recent years, and several reports have stated that it has oocyte collection results similar to those of gonadotropin-releasing hormone antagonist (GnRH-ant) protocol. For emergency fertility preservation, random-start ovarian stimulation is usually recommended. Therefore we compared the clinical outcomes of random-start PPOS with those of conventional random-start GnRH-ant protocols in fertility-preserving cases. Methods We retrospectively examined 86 cycles of oocyte collection, of which 56 were random-start GnRH-ant and 30 were random-start PPOS for fertility preservation at our hospital between January 2016 and April 2021. The primary outcome was the number of mature oocytes per cycle. The secondary outcome was the number of vitrified blastocysts per cycle for embryo freezing cases. Results No significant differences were noted in the number of days of stimulation, total dose of gonadotropin preparation, and the number of mature oocytes and vitrified blastocysts. The number of hospital visits for monitoring was significantly lower in the PPOS group. The start of menstruation before oocyte collection was significantly less in the PPOS group. Conclusions Random-start PPOS and GnRH-ant were similar in oocyte collection results. PPOS can reduce the number of hospital visits, thus reducing patient stress. PPOS at the start of the luteal phase can prevent the start of menstruation during ovarian stimulation.

A simple and economic protocol for efficient in vitro fertilization using cryopreserved mouse sperm

The advent of genome editing tools like CRISPR/Cas has substantially increased the number of genetically engineered mouse models in recent years. In support of refinement and reduction, sperm cryopreservation is advantageous compared to embryo freezing for archiving and distribution of such mouse models. The in vitro fertilization using cryopreserved sperm from the most widely used C57BL/6 strain has become highly efficient in recent years due to several improvements of the procedure. However, purchase of the necessary media for routine application of the current protocol poses a constant burden on budgetary constraints. In-house media preparation, instead, is complex and requires quality control of each batch. Here, we describe a cost-effective and easily adaptable approach for in vitro fertilization using cryopreserved C57BL/6 sperm. This is mainly achieved by modification of an affordable commercial fertilization medium and a step-by-step description of all other necessary reagents. Large-scale comparison of fertilization rates from independent lines of genetically engineered C57BL/6 mice upon cryopreservation and in vitro fertilization with our approach demonstrated equal or significantly superior fertilization rates to current protocols. Our novel SEcuRe (Simple Economical set-up for Rederivation) method provides an affordable, easily adaptable and harmonized protocol for highly efficient rederivation using cryopreserved C57BL/6 sperm for a broad application of colony management in the sense of the 3Rs.

Prolonged Cryopreservation Negatively Affects Embryo Transfer Outcomes Following the Elective Freeze-All Strategy: A Multicenter Retrospective Study

BackgroundWith the development of embryo freezing and warming technology, frozen-thawed embryo transfer (FET) has been widely utilized. However, studies investigating the association between cryopreservation duration and FET outcomes are limited and controversial, and previous studies did not conduct stratification analyses based on demographic or clinical characteristics.MethodsThis multicenter retrospective study included 17,826 women who underwent their first FET following the freeze-all strategy during the period from January 2014 to December 2018. Duration of cryopreservation was categorized into five groups: 3–8 weeks, 8–12 weeks, 12–26 weeks, 26–52 weeks, and >52 weeks. Modified Poisson regression and multivariate logistic regression were used to assess the association between cryostorage time of vitrified embryos and transfer outcomes. Moreover, further stratification analyses were performed according to variables with p <0.05 in multivariate models.ResultsIn this large multicenter study, we observed that storage duration was inversely associated with the possibility of pregnancy and live birth (p <0.001), but not with the risk of ectopic pregnancy and miscarriage. Stratification analyses based on maternal age, the number of oocytes retrieved, and condition of embryo transferred indicated that the inverse correlation was significant in the subpopulation with characteristics: (1) less than 40 years old, (2) more than 3 oocytes retrieved, and (3) only high-quality blastocysts transferred.ConclusionThe results of this large, multicenter, retrospective study suggested that prolonged cryopreservation was inversely associated with the probability of pregnancy and live birth. Therefore, for patients who adopt a freeze-all strategy, early FET might achieve a better outcome.

A simple and economic protocol for efficient in vitro fertilization using cryopreserved mouse sperm v2

The advent of genome editing tools like CRISPR/Cas has substantially increased the number of genetically engineered mouse models in recent years. In support of refinement and reduction, sperm cryopreservation is advantageous compared to embryo freezing for archiving and distribution of such mouse models. The in vitro fertilization using cryopreserved sperm from the most widely used C57BL/6 strain has become highly efficient in recent years due to several improvements of the procedure. However, purchase of the necessary media for routine application of the current protocol poses a constant burden on budgetary constraints. In-house media preparation, instead, is complex and requires quality control of each batch. Here, we describe a cost-effective and easily adaptable approach for in vitro fertilization using cryopreserved C57BL/6 sperm. This is mainly achieved by modification of an affordable commercial fertilization medium and a step-by-step description of all other necessary reagents. This protocol is compatible with frozen sperm from all major repositories and the IVF can easily be adapted to accommodate freshly harvested sperm.

A 3D Printed Vitrification Device for Storage in Cryopreservation Vials

Sperm cryopreservation by vitrification is a promising approach for small-bodied animals such as zebrafish (Danio rerio). However, most vitrification tools adopted in aquatic research were initially designed for applications other than sperm (such as human embryo freezing) and, thus, pose challenges for adoption to sperm vitrification. Three-dimensional (3D) printing combined with open hardware sharing is an emerging strategy to address challenges in the development of cryopreservation tools. The goal of this study was to develop a 3D printed Vitrification Device for Cryo-Vials (VDCV) that can be integrated with the existing vial storage systems. The VDCV combined the vitrification and handling components to achieve functions of sample handling, vitrification, storage, and identification. The vitrification component featured a base, a stem, and a loop. A total of 36 configurations with various loop lengths (8, 10, and 12 mm); loop widths (2.0, 2.5, 3.0, and 3.5 mm); and support structures (open, transverse, and axial) of the VDCD prototypes were designed, fabricated, and tested. Device handling orientations (horizontal and vertical holding angles prior to and during freezing) were also investigated. Computer simulations estimated that the cooling rate of the samples ranged from 0.6–1.5 × 105 °C/min in all the configurations. Prior to freezing, loops with axial supports produced a minimum of 92% film retention. The overall trends of full vitrification occurrence were observed: horizontal plunging > vertical plunging, and axial support > transverse support and open loop. A loop length of 8 mm had the highest overall vitrification occurrence (86–100%). No significant differences (p = 0.6584) were shown in a volume capacity (5.7–6.0 µL) among the three supporting configurations. A single unit of VDCV can provide loading efficiencies of about 6 × 107 sperm/vial, pooling of samples from 3–6 males/vial, and fertilization for 1800 eggs/vial. The VDCV are low-cost (<$0.5 material cost per unit) and can be customized, standardized, securely labeled, and efficiently stored. The prototypes can be accessed by user communities through open-fabrication file sharing and fabricated with consumer-level 3D printers, thus facilitating community-level standardization.

Fresh or Frozen Embryo Selection in Embryo Transfer: Live Birth Rates and Obstetric and Fetal/Neonatal Results

: Assisted reproductive techniques used in the treatment of infertility have been promising methods for infertile individuals. Embryo selection and embryo transfer are an important part of assisting reproductive techniques. The selection of the embryo to be transferred is important for the implantation and clinical pregnancy success. In addition, whether to use a fresh embryo or frozen embryo for embryo transfer is a controversial issue. While the fresh embryo transfer technique is widely used, the frozen embryo transfer technique has become widespread. The main factor in choosing the method of freezing the embryos is to avoid the negative effects of controlled ovarian hyperstimulation on endometrial receptivity. Therefore, it is thought that the use of frozen embryos can improve pregnancy outcomes and reduce the risk of developing obstetric and perinatal problems. However, in the embryo freezing technique, there are problems such as the risk of developing degeneration in the embryo during freezing or thawing process and postponing the transfer. In addition, adverse conditions have been reported such as an increased risk of developing hypertensive disorders in the mother and macrosomia in the baby.

Live birth rate and neonatal outcomes of different quantities and qualities of frozen transferred blastocyst in patients requiring whole embryo freezing stratified by age

Background: Multiple pregnancies are associated with significant complications and health risks for both mothers and infants. Single blastocyst transfer (SBT) is a logical and effective measure to reduce the incidence of multiple pregnancy with assisted reproductive technology (ART). Whether it is suitable for everyone undergoing SBT was inconclusive, in view of the consideration of embryo quality and patients’ age. Therefore, this study aimed to explore live birth rate (LBR) and neonatal outcomes of different quantities and qualities of blastocysts in patients stratified by age, using a cutoff of 35 years, who required whole embryo freezing and underwent a subsequent frozen thawed transfer (FET) cycle.Methods: A total of 3,362 patients were divided into five groups: group A (n=1569) received a single good-quality blastocyst, group B (n=1113) received two good-quality blastocysts, group C (n=313) received one good- and one average-quality blastocyst, group D (n=222) received two average-quality blastocysts, and group E (n=145) received one average-quality blastocyst.Results: For patients who received good-quality blastocysts, irrespective of age, the LBR of double blastocyst transfer (DBT) was about 50–65% and the multiple pregnancy rate (MPR) was 40–60%; however, the LBR of SBT was 40–55%, and the MPR was 3.5–6.3%. For patients who only had average-quality blastocysts, the MPR of double average-quality blastocyst transfer was as high as 30–50%. Moreover, about 70–90% of preterm births resulted from multiple pregnancies, and about 85–95% of low birth weight babies come from multiple pregnancies. The neonatal outcomes (gestational age, birth weight, and birth height) of DBT were significantly lower than those of SBT regardless of age, and this statistical difference disappeared if the patients were subgrouped by singleton or twin. There is no significant difference in neonatal outcomes between single good-quality blastocyst and single average-quality blastocyst transfer.Conclusions: SBT is a preferable option for patients regardless of age when good-quality blastocysts are available. For patients who only had average-quality blastocysts, they should be informed that DBT was associated with higher multiple pregnancy and adverse neonatal outcomes when compared with SBT regardless of age, suggesting that the practice of SBT is also feasible for these patients.

Live birth rate and neonatal outcomes of different quantities and qualities of frozen transferred blastocyst in patients requiring whole embryo freezing stratified by age

Background Multiple pregnancies are associated with significant complications and health risks for both mothers and infants. Single blastocyst transfer (SBT) is a logical and effective measure to reduce the incidence of multiple pregnancy with assisted reproductive technology (ART). Whether it is suitable for everyone undergoing SBT was inconclusive, in view of the consideration of embryo quality and patients’ age. Therefore, this study aimed to explore live birth rate (LBR) and neonatal outcomes of different quantities and qualities of blastocysts in patients stratified by age, using a cutoff of 35 years, who required whole embryo freezing and underwent a subsequent frozen thawed transfer (FET) cycle. Methods Atotal of 3,362 patients were divided into five groups: group A (n=1569) received a single good-quality blastocyst, group B (n=1113) received two good-quality blastocysts, group C (n=313) received one good-and one average-quality blastocyst, group D (n=222) received two average-quality blastocysts, and group E (n=145) received one average-quality blastocyst. Results For patients who received good-quality blastocysts, irrespective of age, the LBR of double blastocyst transfer (DBT) was about 50–65% and the multiple pregnancy rate (MPR) was 40–60%; however, the LBR of SBT was 40–55%, and the MPR was 3.5–6.3%. For patients who only had average-quality blastocysts, the MPR of double average-quality blastocyst transfer was as high as 30–50%. Moreover, about 70–90% of preterm births resulted from multiple pregnancies, and about 85–95% of low birth weight babies come from multiple pregnancies. The neonatal outcomes (gestational age, birth weight, and birth height) of DBT were significantly lower than those of SBT regardless of age, and this statistical difference disappeared if the patients were subgrouped by singleton or twin. There is no significant difference in neonatal outcomes between single good-quality blastocyst and single average-quality blastocyst transfer. Conclusions SBT is a preferable option for patients regardless of age when good-quality blastocysts are available. For patients who only had average-quality blastocysts, they should be informed that DBT was associated with higher multiple pregnancy and adverse neonatal outcomes when compared with SBT regardless of age, suggesting that the practice of SBT is also feasible for these patients.