Comparison of four methods for sperm preparation for IUI

Production of transgenic first filial puppies expressing mutated human amyloid precursor protein gene

Propagation of transgenic animals by germline transmission using assisted reproductive technologies such as in vitro fertilization (IVF) is the most efficient way to produce transgenic colonies for biomedical research. The objective of this study was to generate transgenic puppies from a founder dog expressing the mutated human amyloid precursor protein (mhAPP) gene. Experiment I assessed the characteristics of the semen prepared by freshly diluted, swim-up, and Percoll gradient methods using a computer-assisted semen analyzer (CASA). Motile and progressively motile sperm counts were higher in the Percoll gradient samples (p < 0.05) than in the swim-up and freshly diluted samples. In Experiment II, a total of 59, 70, and 65 presumptive zygotes produced by fresh, Percoll gradient, and swim-up methods, respectively, were transferred to surrogates (5 for each group); the Percoll gradient (27.27%) and swim-up samples (14.29%) showed the highest blastocyst formation rates, while fresh diluted semen did not produce any blastocyst. Experiment III examined the full-term developmental ability of embryos. Among the 5 surrogates in the Percoll gradient group, one (20.0%) became pregnant; it had 4 (6.15%) sacs and delivered 4 (6.15%; 2 males and 2 females) live puppies. Among the 4 puppies, 2 (50.0%) were found to transmit the transgene on their nail and toe under GFP fluorescence. Furthermore, the integration and expression of the mhAPP transgene were examined in the umbilical cords of all the IVF-derived puppies, and the presence of the transgene was only observed in the GFP-positive puppies. Thus, semen prepared by the Percoll method could generate transgenic puppies by male germline transmission using the IVF technique. Our result will help propagate transgenic dogs efficiently, which will foster human biomedical research.

Prediction of Sperm Progression in Three Dimensions Using Rapid Optical Imaging and Dynamic Mechanical Modeling

We present a multidisciplinary approach for predicting how sperm cells with various morphologies swim in three-dimensions (3D), from milliseconds to much longer time scales at spatial resolutions of less than half a micron. We created the sperm 3D geometry and built a numerical mechanical model using the experimentally acquired dynamic 3D refractive-index profiles of sperm cells swimming in vitro as imaged by high-resolution optical diffraction tomography. By controlling parameters in the model, such as the size and shape of the sperm head and tail, we can then predict how different sperm cells, normal or abnormal, would swim in 3D, in the short or long term. We quantified various 3D structural factor effects on the sperm long-term motility. We found that some abnormal sperm cells swim faster than normal sperm cells, in contrast to the commonly used sperm selection assumption during in vitro fertilization (IVF), according to which sperm cells should mainly be chosen based on their progressive motion. We thus establish a new tool for sperm analysis and male-infertility diagnosis, as well as sperm selection criteria for fertility treatments.

Relationship between sperm parameters and clinical outcomes of Intra Uterine Insemination (IUI)

Background:

Intrauterine insemination (IUI) is a widely utilized method for treating the infertile couples. The aim of the present study was to determine the pregnancy and abortion rates after IUI and to examine the relationship of sperm parameters with these rates.

Methods:

This retrospective study was performed on 911 infertile couples undergoing IUI treatment in Shahid Akbarabadi IVF Centre from May 2017 to May 2019. To evaluate the correlation of sperm parameters with the clinical pregnancy and abortion rates, odds ratio (OR) with 95% confidence intervals (CI) was calculated.

Results:

In this study, the pregnancy rate following IUI was 15.7% (143/911), and among women who achieved pregnancy, the abortion rate was 42.0% (60/143). According to the multiple logistic regression analysis, none of the sperm parameters was associated with the pregnancy rate. Couples with either male or female factor infertility etiologies were more likely to get pregnant than those with unexplained infertility. Regarding the abortion rate, multiple logistic regression analysis revealed that normal sperm count was related to a lower abortion rate (adjusted OR=0.25, 95% CI=0.07–0.91).

Conclusion:

The present study did not reveal a significant relationship between none of the sperm parameters and pregnancy rate after IUI treatment. However, among women who got pregnant, continuation of the pregnancy was associated with the normal sperm count. Furthermore, analysis of all semen parameters together in comparison to one parameter alone might be more accurate to predict pregnancy or abortion. Further prospective cohort studies with a large number of couples are required.

An update on the techniques used to measure oxidative stress in seminal plasma

Reactive oxygen species (ROS) are produced in significant amounts by spermatozoa and leucocytes. They are necessary to carry out various physiological functions such as sperm capacitation, hyperactivation, acrosome reaction, sperm-zona binding and cellular signalling pathways. Oxidative stress (OS) results when the ROS levels overwhelm the available antioxidant reserve. A number of direct and indirect tests have been developed to assess oxidative stress. In this manuscript, we discuss these common direct and indirect tests as well as their advantages and disadvantages. Tests measuring sperm dysfunction secondary to oxidative stress such as lipid peroxidation, DNA fragmentation and protein alterations are also described.

Reactive oxygen species in reproduction: harmful, essential or both?

The process of embryonic development is crucial and radically influences preimplantation embryo competence. It involves oocyte maturation, fertilization, cell division and blastulation and is characterized by different key phases that have major influences on embryo quality. Each stage of the process of preimplantation embryonic development is led by important signalling pathways that include very many regulatory molecules, such as primary and secondary messengers. Many studies, both in vivo and in vitro, have shown the importance of the contribution of reactive oxygen species (ROS) as important second messengers in embryo development. ROS may originate from embryo metabolism and/or oocyte/embryo surroundings, and their effect on embryonic development is highly variable, depending on the needs of the embryo at each stage of development and on their environment (in vivo or under in vitro culture conditions). Other studies have also shown the deleterious effects of ROS in embryo development, when cellular tissue production overwhelms antioxidant production, leading to oxidative stress. This stress is known to be the cause of many cellular alterations, such as protein, lipid, and DNA damage. Considering that the same ROS level can have a deleterious effect on the fertilizing oocyte or embryo at certain stages, and a positive effect at another stage of the development process, further studies need to be carried out to determine the rate of ROS that benefits the embryo and from what rate it starts to be harmful, this measured at each key phase of embryonic development.

Semen preparation techniques for intrauterine insemination

BACKGROUND

Semen preparation techniques for assisted reproduction, including intrauterine insemination (IUI), were developed to select the motile morphologically normal spermatozoa. The yield of many motile, morphologically normal spermatozoa might influence treatment choices and therefore outcomes.

OBJECTIVES

To compare the effectiveness of three different semen preparation techniques (gradient; swim-up; wash and centrifugation) on clinical outcomes (live birth rate; clinical pregnancy rate) in subfertile couples undergoing IUI.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group (CGFG) trials register, CENTRAL, MEDLINE, Embase, Science Direct Database, National Research Register, Biological Abstracts and clinical trial registries in March 2019, and checked references and contacted study authors to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing the efficacy in terms of clinical outcomes of semen preparation techniques used for subfertile couples undergoing IUI.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcomes are live birth rate and clinical pregnancy rate per couple.

MAIN RESULTS

We included seven RCTS in the review; we included six of these, totalling 485 couples, in the meta-analysis. No trials reported the primary outcome of live birth. The evidence was of very low-quality. The main limitations were (unclear) risk of bias, signs of imprecision and inconsistency in results among studies and the small number of studies/participants included.Swim-up versus gradient technique Considering the quality of evidence, we are uncertain whether there was a difference between clinical pregnancy rates (CPR) for swim-up versus a gradient technique (odds ratio (OR) 0.83, 95% CI 0.51 to 1.35; I² = 71%; 4 RCTs, 370 participants; very low-quality evidence). The results suggest that if the chance of pregnancy after the use of a gradient technique is assumed to be 24%, the chance of pregnancy after using the swim-up technique is between 14% and 30%. We are uncertain whether there was a real difference between ongoing pregnancy rates per couple (OR 0.39, 95% CI 0.19 to 0.82; heterogeneity not applicable; 1 RCT, 223 participants; very low-quality evidence). Considering the quality of evidence, we are uncertain whether there was a difference between multiple pregnancy rates (MPR) per couple comparing a swim-up versus gradient technique (MPR per couple 0% versus 0%; 1 RCT, 25 participants; very low-quality of evidence). Considering the quality of evidence, we are also uncertain whether there was a difference between miscarriage rates (MR) per couple comparing a swim-up versus gradient technique (OR 0.85, 95% CI 0.28 to 2.59; I² = 44%; 3 RCTs, 330 participants; very low-quality evidence). No studies reported on ectopic pregnancy rate, fetal abnormalities or infection rate.Swim-up versus wash techniqueConsidering the quality of evidence, we are uncertain whether there is a difference in clinical pregnancy rates after a swim-up technique versus wash and centrifugation (OR 0.41, 95% CI 0.15 to 1.13; I² = 55%; 2 RCTs, 78 participants; very low-quality evidence). The results suggest that if the chance of pregnancy after the use of a wash technique is assumed to be 38%, the chance of pregnancy after using the swim-up technique is between 9% and 41%. Considering the quality of evidence, we are uncertain whether there was a difference between multiple pregnancy rates between swim-up technique versus wash technique (OR 0.49, 95% CI 0.02 to 13.28; heterogeneity not applicable; 1 RCT, 26 participants; very low-quality evidence). Miscarriage rate was only reported by one study: no miscarriages were reported in either treatment arm. No studies reported on ongoing pregnancy rate, ectopic pregnancy rate, fetal abnormalities or infection rate.Gradient versus wash techniqueConsidering the quality of evidence, we are uncertain whether there is a difference in clinical pregnancy rates after a gradient versus wash and centrifugation technique (OR 1.78, 95% CI 0.58 to 5.46; I² = 52%; 2 RCTs, 94 participants; very low-quality evidence). The results suggest that if the chance of pregnancy after the use of a wash technique is assumed to be 13%, the chance of pregnancy after using the gradient technique is between 8% and 46%. Considering the quality of evidence, we are uncertain whether there was a difference between multiple pregnancy rates per couple between the treatment groups (OR 0.33, 95% CI 0.01 to 8.83; very low-quality evidence). Considering the quality of evidence, we are also uncertain whether there was a difference between miscarriage rates per couple between the treatment groups (OR 6.11, 95% CI 0.27 to 138.45; very low-quality evidence). No studies reported on ongoing pregnancy rate, ectopic pregnancy rate, fetal abnormalities or infection rate.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend any specific semen preparation technique: swim-up versus gradient versus wash and centrifugation technique. No studies reported on live birth rates. Considering the quality of evidence (very low), we are uncertain whether there is a difference in clinical pregnancy rates, ongoing pregnancy rates, multiple pregnancy rates or miscarriage rates per couple) between the three sperm preparation techniques. Further randomised trials are warranted that report live birth data.

Sperm DNA fragmentation index influences assisted reproductive technology outcome: A systematic review and meta-analysis combined with a retrospective cohort study

Studies have explored the influence of DNA damage in assisted reproductive technology (ART), but the outcome remains controversial. To determine whether sperm DNA fragmentation index (DFI) has any effect on ART outcomes, we collected detailed data regarding 1,333 IVF cycles performed at our centre, and the data of our retrospective cohort study were extracted for this meta-analysis. We searched PubMed, Web of Science, EMBASE and Google Scholar and performed a systemic review and meta-analysis. Primary meta-analysis of 10 studies comprising 1,785 couples showed that live birth rate was no significantly different between low-DFI group and high-DFI group (p > 0.05). Secondary meta-analysis of 25 studies comprising 3,992 couples showed a higher miscarriage rate in high-DFI group than in low-DFI group (RR=1.57 [1.18, 2.09], p < 0.01). Meta-analysis of eight studies comprising 17,879 embryos revealed a lower good-quality embryo rate (RR=0.65 [0.62, 0.68], p < 0.01). Meta-analysis of 23 studies comprising 6,771 cycles showed that the high-DFI group had a lower clinical pregnancy rate than low-DFI group (RR=0.85 [0.75, 0.96], p < 0.01). Heterogeneity of included studies weakened our conclusions. Our study showed that DFI has adverse effects on ART outcome. More well-designed studies exploring the association between DFI and ART outcome are desired.

Techniques used for IUI: is it time for a change?

STUDY QUESTION

Are the guidelines for the technical aspects of IUI (WHO, 2010) still in accordance with the current literature?

SUMMARY ANSWER

In general, the laboratory guidelines of the World Health Organization (WHO) are a suitable protocol, although the evidence is not always conclusive and some changes are advisable.

WHAT IS KNOWN ALREADY

Lack of standardization of the technical procedures required for IUI might result in inter-laboratory variation in pregnancy rates. Most centers still use their own materials and methods even though some guidelines are available.

STUDY DESIGN, SIZE, DURATION

A structural review focusing on the association between pregnancy rates and the procedures of semen collection (e.g. ejaculatory abstinence, collection place), semen processing (e.g. preparation method, temperature during centrifugation/storage), insemination (e.g. timing of IUI, bed rest after IUI) and the equipment used.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A literature search was performed in Medline and the Cochrane library. When no adequate studies of the impact of a parameter on pregnancy results were found, its association with sperm parameters was reviewed.

MAIN RESULTS AND THE ROLE OF CHANCE

For most variables, the literature review revealed a low level of evidence, a limited number of studies and/or an inadequate outcome measure. Moreover, the comparison of procedures (i.e. semen preparation technique, time interval between semen, collection, processing and IUI) revealed no consensus about their results. It was not possible to develop an evidence-based, optimal IUI treatment protocol.

LIMITATIONS, REASONS FOR CAUTION

The included studies exhibited a lack of standardization in inclusion criteria and methods used.

WIDER IMPLICATIONS OF THE FINDINGS

This review emphasizes the need for more knowledge about and standardization of assisted reproduction technologies. Our literature search indicates that some of the recommendations in the laboratory guidelines could be adapted to improve standardization, comfort, quality control and to cut costs.

STUDY FUNDING/COMPETING INTEREST(S)

The Dutch Foundation for Quality Assessment in Medical Laboratories (SKML), Nijmegen, The Netherlands. S.K. and W.N. have no conflicts of interest to disclose. C.B. and A.W. are members of the board of the SKML. With a grant from SKML, L.L. was paid for her time to perform the research and write the publication. D.B. received grants from Merck Serono, Ferring and MSD, outside the submitted work.

REGISTRATION NUMBER

N/A.

Semen preparation methods and sperm telomere length: density gradient centrifugation versus the swim up procedure

Previous studies have shown that both density gradient centrifugation (DGC) and swim up (SU) procedures can select spermatozoa with longer telomeres for assisted reproduction techniques (ART). However, it is unknown which approach is more effective. The aim of the present study was to compare the effects of these two methods on sperm telomere length (STL). A total of 150 normozoospermic subjects were recruited. STL, DNA fragmentation index (DFI), reactive oxygen species (ROS) content and progressive motility of semen samples were detected before and after the procedures of DGC and SU. When compared to raw semen, the average length of sperm telomeres was significantly longer after the two sperm preparation methods. However, no significant difference was found between the DGC and SU procedures. We also found that semen prepared by the two methods had lower DNA fragmentation, ROS content and sperm progressive motility. However, no significant difference was found in those parameters between the two procedures. This is the first study that compares the effects of the DGC and SU procedures on STL, and the results show that both methods can recover a sperm population with longer STL and better DNA integrity for ART.

The pellet swim-up is the best technique for sperm preparation during in vitro fertilization procedures

PURPOSE

The aim of this study was to investigate the most suitable sperm preparation technique to apply in order to obtain a spermatozoon population with minimal DNA damage during in vitro fertilization procedures. We compared four preparation techniques: direct swim-up (DSU), pellet swim-up (PSU), density gradient (DG), and density gradient followed by swim-up (DG-SU), evaluating the effects of each technique on the DNA damage rate, evaluated by DNA fragmentation index of the spermatozoa obtained.

METHODS

In this observational study, 98 semen samples from couples undergoing IVF/ICSI cycles were included. Data were collected between April and November 2014 at the ANDROS Day Surgery Clinic, Palermo, Italy.

RESULT(S)

The percentages of DNA fragmentation were 18.30 ± 10.8 in raw samples, 6.6 ± 5.7 after DSU, 4.2 ± 3.8 after PSU, 12.9 ± 9.9 after DG, and 3.7 ± 4.0 after DG-SU respectively. Compared to the raw evaluation, all the preparation techniques significantly decreased the total rate of the DNA fragmentation (DSU Z = -8.60, P < 0.008; PSU Z = -8.54, P < 0.008; DG Z = -6.42, P < 0.008, and DG-SU Z = -8.60, P < 0.008, respectively). Comparing them, spermatozoa with intact DNA after PSU and DG-SU were significantly higher than after DSU (Z = -7.12, P < 0.008; Z = -6.59, P < 0.008, respectively) and after DG (Z = -8.41, P < 0.008; Z = -8.60, P < 0.008, respectively). The difference between PSU and DG-SU was not significant (Z = -2.21, P = 0.03).

CONCLUSION(S)

There are, above all, two techniques of sperm preparation which allow for the recovery of spermatozoa with the lowest DNA fragmentation rate. Furthermore, given low costs and reduced time, we believe that PSU is the best option in the treatment of semen samples during IVF/ICSI.

SPINK3 modulates mouse sperm physiology through the reduction of nitric oxide level independently of its trypsin inhibitory activity

Serine protease inhibitor Kazal-type (SPINK3)/P12/PSTI-II is a small secretory protein from mouse seminal vesicle which contains a KAZAL domain and shows calcium (Ca2+)-transport inhibitory (caltrin) activity. This molecule was obtained as a recombinant protein and its effect on capacitated sperm cells was examined. SPINK3 inhibited trypsin activityin vitrowhile the fusion protein GST-SPINK3 had no effect on this enzyme activity. The inactive GST-SPINK3 significantly reduced the percentage of spermatozoa positively stained for nitric oxide (NO) with the specific probe DAF-FM DA and NO concentration measured by Griess method in capacitated mouse sperm; the same effect was observed when sperm were capacitated under low Ca2+concentration, using either intracellular (BAPTA-AM) or extracellular Ca2+(EDTA) chelators. The percentage of sperm showing spontaneous and progesterone-induced acrosomal reaction was significantly lower in the presence of GST-SPINK3 compared to untreated capacitated spermatozoa. Interestingly, this decrease was overcome by the exogenous addition of the NO donors, sodium nitroprusside (SNP), andS-nitrosoglutathione (GSNO). Phosphorylation of sperm proteins in tyrosine residues was partially affected by GST-SPINK3, however, only GSNO was able to reverse this effect. Sperm progressive motility was not significantly diminished by GST-SPINK3 or BAPTA-AM but enhanced by the addition of SNP. This is the first report that demonstrates that SPINK3 modulates sperm physiology through a downstream reduction of endogenous NO concentration and independently of SPINK3 trypsin inhibitory activity.

The potential use of intrauterine insemination as a basic option for infertility: a review for technology-limited medical settings

Objective. There is an asymmetric allocation of technology and other resources for infertility services. Intrauterine insemination (IUI) is a process of placing washed spermatozoa transcervically into the uterine cavity for treatment of infertility. This is a review of literature for the potential use of IUI as a basic infertility treatment in technology-limited settings. Study design. Review of articles on treatment of infertility using IUI. Results. Aspects regarding the use of IUI are reviewed, including ovarian stimulation, semen parameters associated with good outcomes, methods of sperm preparation, timing of IUI, and number of inseminations. Implications of the finding in light of the needs of low-technology medical settings are summarized. Conclusion. The reviewed evidence suggests that IUI is less expensive, less invasive, and comparably effective for selected patients as a first-line treatment for couples with unexplained or male factor infertility. Those couples may be offered three to six IUI cycles in technology-limited settings.

Semen preparation techniques for intrauterine insemination

BACKGROUND

Semen preparation techniques for assisted reproduction, including intrauterine insemination (IUI), were developed to separate the motile morphological normal spermatozoa. Leucocytes, bacteria and dead spermatozoa produce oxygen radicals that negatively influence the ability to fertilize the egg. The yield of as many motile, morphologically normal spermatozoa as possible might influence treatment choices and therefore outcomes.

OBJECTIVES

To compare the effectiveness of gradient, swim-up, or wash and centrifugation semen preparation techniques on clinical outcome in subfertile couples undergoing intrauterine insemination (IUI).

SEARCH STRATEGY

We searched the Menstrual Disorders and Subfertility Group Trials Register (13 January 2007), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 2), MEDLINE (1966 to January 2007 ), EMBASE (1980 to January 2007), Science Direct Database (1966 to January 2007), National Research Register (2000 to 2007), Biological Abstracts (2000 to January 2007), CINAHL (1982 to October 2006) and reference lists of relevant articles. We also contacted experts and authors in the field.

SELECTION CRITERIA

Parallel randomized controlled trials (RCTs) comparing the efficacy of semen preparation techniques used for subfertile couples undergoing IUI in terms of clinical outcome were included.

DATA COLLECTION AND ANALYSIS

Two reviewer authors independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Five RCTs, including 262 couples in total, were included in the meta-analysis (Dodson 1998; Grigoriou 2005; Posada 2005; Soliman 2005; Xu 2000). Xu compared the three techniques; Soliman compared a gradient technique versus a wash technique; Dodson and Posada compared a gradient technique versus a swim-up technique; whereas Grigoriou compared swim-up versus a wash technique. No trials reported the primary outcome of live birth. There was no evidence of a difference between pregnancy rates (PR) for swim-up versus a gradient or wash and centrifugation technique (Peto OR 1.57, 95% CI 0.74 to 3.32; Peto OR 0.41, 95% CI 0.15 to 1.10, respectively); nor in the two studies comparing a gradient technique versus wash and centrifugation (Peto OR 1.76, 95% CI 0.57 to 5.44). There was no evidence of a difference in the miscarriage rate (MR) in two studies comparing swim-up versus a gradient technique (Peto OR 0.13, 95% CI 0.01 to 1.33).

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend any specific preparation technique. Large high quality randomised controlled trials, comparing the effectiveness of a gradient and/ or a swim-up and/ or wash and centrifugation technique on clinical outcome are lacking. Further randomised trials are warranted.

Predictive value of the hemizona assay for pregnancy outcome in patients undergoing controlled ovarian hyperstimulation with intrauterine insemination

OBJECTIVE

The hemizona assay (HZA) is an established functional test that examines in vitro sperm-zona pellucida binding capacity with high predictive power for fertilization outcome in IVF. The objective of this study was to evaluate the value of the HZA as a predictor of pregnancy in patients undergoing controlled ovarian hyperstimulation (COH) and intrauterine insemination (IUI).

DESIGN

Prospective clinical study.

SETTING

Academic center.

PATIENT(S)

Eighty-two couples with unexplained or male factor infertility that underwent 313 IUI cycles.

INTERVENTION(S)

Basic semen analysis and HZA were performed within three months of starting COH/IUI therapy.

MAIN OUTCOME MEASURE(S)

Hemizona index (HZI) and clinical pregnancy.

RESULT(S)

Overall, patients with an HZI of <30 had a significantly lower pregnancy rate compared to patients with an HZI of > or =30 (11.1% vs. 40.6%, respectively; P<.05; relative risk for failure to conceive: 1.5 (confidence interval 1.2-1.9)). In all patients combined, and in the range of HZI 0-60, the duration of infertility (P=.000) and the HZI (P=.004) were significant determinants of conception (receiver operating characteristics (ROC) analysis). In couples with male infertility, the average path velocity and HZI were significant predictors of conception (P=.001 and P=.005, respectively, ROC analysis). The negative and positive predictive values of the HZA for pregnancy were 93% and 69%, respectively. Logistic regression analysis provided models of HZI (P=.021) and duration of infertility (P=.037) with highest predictability of conception in male factor and unexplained infertility groups, respectively.

CONCLUSION(S)

The HZA predicted pregnancy in the IUI setting with high sensitivity and negative predictive value in couples with male infertility. Results of this sperm function test are useful in counseling couples before allocating them into COH/IUI therapy.