24 research outputs found
Revealing the secret life of pre-implantation embryos by time-lapse monitoring: A review
No full textHigh implantation success following in vitro fertilization cycles are achieved via the
transfer of embryos with the highest developmental competence. Multiple
pregnancies as a result of the transfer of several embryos per cycle accompany with
various complication. Thus, single-embryo transfer (SET) is the preferred practice in
assisted reproductive technique (ART) treatment. In order to improve the pregnancy
rate for SET, embryologists need reliable biomarkers to aid their selection of
embryos with the highest developmental potential. Time-lapse technology is a
noninvasive alternative conventional microscopic assessment. It provides
uninterrupted and continues the survey of embryo development to transfer day.
Today, there are four time-lapse systems that are commercially available for ART
centers. In world and Iran, the first time lapse babies were born in 2010 and 2015,
respectively, conceived by SET. Here, we review the use of time-lapse monitoring in
the observation of embryogenesis as well as its role in SET. Although, the findings
from our review support common use of time-lapse monitoring in ART centers; but,
future large studies assessing this system in well-designed trials are necessary
Efficacy of the in vitro splitting of human preimplantation embryos from ART programs
No full textThe aim of this study was to evaluate the efficiency of in vitro embryo splitting (IES) procedures. We also assessed the
quality of the blastocysts developed from embryos obtained from different sources
Human cumulus cell sensitivity to vitrification, an ultrastructural study
No full textCumulus cells (CCs) play an important role in the regulation of female gamete development, meiotic maturation, oocyte-sperm interaction, capacitation and acrosome reaction. However, their role in maintaining oocyte competence after vitrification is unclear as controversial data on their protecting action against oocyte cryoinjuries are available. Here we described the effects of vitrification on the ultrastructure of human CCs collected from women undergoing assisted reproductive technologies (ARTs). In total, 50 patches of CCs, sampled from high-quality human cumulus-oocyte complexes, were randomly allocated into two groups after patient informed consent: 1, fresh CCs (controls, n = 25); 2, vitrified CCs (n = 25). Samples were then prepared and observed by transmission electron microscopy. In fresh CCs, in which small cell clusters were visible, cell membranes were joined by focal gap junctions. Microvilli were rare and short. Nuclei, mitochondria, smooth endoplasmic reticulum (SER), Golgi apparatus and lipid droplets appeared well preserved; vacuoles were scarce. After vitrification, we observed two populations of CCs: light CCs, with a smooth appearance and few short microvilli; and dark CCs, with numerous and long microvilli. In both, most of the organelles appeared similar to those of fresh CCs. Lipid droplets were denser and more numerous, with respect to fresh CCs. They were mainly located in the peri-nuclear and sub-plasmalemmal regions. Numerous packed electron-negative vacuoles were visible. The vitrification procedure did not cause alterations in the fine structure of major organelles, except for an increased amount of lipid droplets and vacuoles. This specific sensitivity of human CCs to vitrification should be considered during ARTs
Impact of different embryo loading techniques on pregnancy rates in in vitro fertlizaton/embryo transfer cycles
No full textBackground: Embryo transfer (ET) technique is one of the important factors of in vitro fertlization success. Among the different steps in ET technique, less attention has been given to embryo loading (EL). The aim was to compare the impact of two different techniques of EL on pregnancy rate in IVF/ET cycles. Materials and Methods: In this retrospective study, 144 and 170 patients were placed in groups A and B, respectively. In Group A, the embryos were drawn directly into the ET catheter from culture microdrop under the oil. In Group B, the embryos were transferred from culture microdrop into G2 medium in center-well dish. Then, the embryos were drawn into the catheter and finally transferred into the uterus. Both groups were adjusted for other parameters based on the EL technique. The main outcome measure was pregnancy rate. Results: There were insignificant differences for etiology of infertility, source of sperm, type of stimulation protocol, percent of IVF or intracytoplasmic sperm injection type of ET catheter, cycles with good quality embryos and transferred embryos between two groups. The rate of both chemical and clinical pregnancy was higher in Group B compared to A, but the difference was insignificant (P = 0.09 and P = 0.1, respectively). Conclusion: It seems that there is no difference in the outcome by loading the embryo from microdrop or center-well dish
Is there any correlation between oocyte polarization microscopy findings with embryo time lapse monitoring in ICSI program?
No full textNo cytotoxic effects from application of pentoxifylline to spermatozoa on subsequent pre-implantation embryo development in mice
No full textThe aim was to assess the effect of spermatozoa exposed to PTX on the rates of fertilization and embryo development and apoptotic cells within blastocysts in an animal model. Mice Oocytes were inseminated with spermatozoa exposed to 3.6 mmol PTX for 30 min, or with neat spermatozoa. Then fertilization and embryo development rate, blastocyst formation and quality, as well as total cell number of blastocyst, and DNA fragmentation index (DFI) in blastocysts were surveyed in both groups. Fertilization and embryo development rate were similar between the groups. The rates of blastocyst formation did not differ significantly between control and PTX groups (52.4% vs. 51.8%). The average of total cell count in blastocysts and DFI in control and PTX groups were also insignificant (31.08 ± 1.5 vs. 34.14 ± 1.5 and 9.76 ± 5.0 vs. 11.77 ± 5.4). Application of PTX for enhancing sperm motility does not cause a cytotoxic effect on subsequent embryo development and embryo genome integrity
Morphology and viability of human spermatozoa vitrified with a new, cryoprotectant-free, artificial seminal fluid
No full textCryopreservation is a process finalized to store tissues and cells at a very low temperature. The most common freezing protocols used for gamete preservation in Assisted Reproductive Technologies are slow freezing and vitrification (1). Vitrification combines ultrarapid cooling with high concentrations of cryoprotectants; it avoids, better than slow freezing, the formation of ice crystals. It has been demonstrated, however, that cryoprotectant addition may significantly reduce cell viability (2). This study was aimed to design a new, cryoprotectant-free, medium similar to normal human seminal fluid (SF) formulation (artificial seminal fluid; ASF), and to compare the cryoprotective potential of this medium with SF and Human tubal fluid (HTF) medium. Thirty normal ejaculates were processed with swim-up technique and sperm suspensions were divided in four groups: fresh (controls); vitrified in HTF (Vit HTF); vitrified in patients’ SF (Vit SF); and vitrified in ASF (Vit ASF). To identify the effects of the different media we assessed sperm parameters of motility, viability and morphology after warming. Spermatozoa ultrastructure was also evaluated by scanning and transmission electron microscopy (SEM and TEM). The results showed that sperm motility, viability and normal morphology were significantly higher in Vit ASF than in Vit HTF. The same parameters were better in Vit ASF than in Vit SF, but only viability differed significantly. Deep cytoplasmic invaginations and folded tails were commonly observed by SEM in all vitrified sperms, but this alterations were more evident in Vit HTF and Vit SF than in Vit ASF. By TEM, acrosome damage, plasma membrane loss, chromatin vacuolation, disruption of mitochondria and adherence of several tail sections together were observed in all vitrified groups; the latter phenomenon, however, was more evident in Vit HTF and Vit SF than in Vit ASF. In conclusion, vitrification of human spermatozoa with ASF seems more effective in preserving sperm quality than Vit SF and, particularly, Vit HTF
Quality of testicular spermatozoa improves with changes in composition of culture medium
No full textAbstract Background Spermatozoa retrieved from the testis and epididymis are deprived of the beneficial effects of seminal fluid. Thus applying an artificial medium with normal seminal fluid characteristics, known as artificial seminal fluid (ASF), may provide an appropriate condition for improving some sperm parameters in azoospermia. The objective was to investigate the impact of in vitro exposure of testicular and epididymal spermatozoa to ASF on sperm quality. The study was conducted on testicular (n = 20) and epididymal (n = 20) sperm specimens obtained from azoospermic men. Each sample was divided into two equal parts: Part I) for processing and incubation with Ham’s F10 medium; Part II) for processing and incubation with ASF. Results After 2 h incubation, testicular sperm motility was significantly higher in ASF than in Ham’s F10 medium. In comparison to 0 h, mitochondrial membrane potential levels of testicular spermatozoa were significantly higher after 2 h and 24 h in ASF and after 24 h in Ham’s F10 medium. Furthermore, the data indicated significantly lower rates of epididymal spermatozoa with high MMP in both media after 24 h. There were no significant differences in the DNA fragmentation index of testicular and epididymal spermatozoa between ASF and Ham’s F10 medium at different time points. Conclusion The results demonstrated that in vitro incubation of testicular spermatozoa improved their motility more effectively than Ham’s F10 medium in the short term (2 h), but had no effect on epididymal spermatozoa. Since the physiology of testicular spermatozoa is different from that of ejaculated spermatozoa, it seems that a special environment should be designed and used for each of them
A comparison of sperm parameters DNA fragmentation and telomere length in testicular versus ejaculated spermatozoa
No full textAbstract While previous studies reported conflicting findings on DNA fragmentation in testicular versus ejaculated spermatozoa, this study aimed to perform a detailed analysis of testicular spermatozoa, evaluating sperm parameters and detailed morphology, DNA fragmentation, and relative telomere length across testicular and ejaculated spermatozoa. The study included 60 men in four groups: normozoospermic men (control), men with oligoasthenoteratozoospermia (OAT), men with a history of sperm presence in the semen who were candidates for conventional testicular sperm extraction (TESE), and non-obstructive azoospermia (NOA) patients undergoing microdissection testicular sperm extraction (M-TESE). Spermatozoa were evaluated for vitality (eosin staining), teratozoospermia Index (TZI) and detailed morphology (Diff-Quik staining), DNA fragmentation (sperm chromatin dispersion assay), and relative telomere length (q-PCR). The results demonstrated that sperm vitality was significantly lower in the OAT group. The control group showed markedly higher rate of normal morphology and lower TZI compared to the OAT, TESE, and M-TESE groups. The TESE and M-TESE groups showed higher rates of head-midpiece abnormalities and residual bodies compared to the control group (P < 0.0001, P < 0.0001, respectively). Sperm DNA fragmentation in the control group showed a significant decrease relative to all experimental groups (P < 0.0001). The control group demonstrated a significantly higher proportion of sperm with intact acrosomes than all experimental groups (P < 0.0001). Moreover, the relative sperm telomere length was markedly lower in the M-TESE group compared to the control (P = 0.0006), OAT, and TESE groups (P < 0.0001). Our results demonstrated that testicular sperm have significantly elevated DNA damage levels. Moreover, these spermatozoa exhibit increased frequencies of morphological abnormalities in the head and midpiece regions, reacted acrosomes, and residual bodies
