Semen parameters and sperm morphology in men in unexplained recurrent spontaneous abortion, before and during a 3 year follow-up period

Male Contributory Factors in Recurrent Pregnancy Loss

With 40% of idiopathic cases, recurrent pregnancy loss (RPL) is a problem of great concern for patients and clinicians. In addition to financial burden, it causes a lot of frustration and anxiety in affected couples. The primary objective of this review was to gain knowledge of recent advances in the field of recurrent pregnancy losses and to understand the role of male contributory factors in idiopathic cases. For a long time, researchers and clinicians were seeking an explanation for idiopathic RPL (iRPL) in females only; however, with recent advances in reproductive biology, the role of spermatozoa in early embryonic development has caught the attention of researchers. Clinically, only routine semen parameters and karyotyping are investigated in iRPL male partners, which seem to be insufficient in the present scenario, and thus, more information at the molecular level is required for a comprehensive understanding of iRPL. In concluding remarks, we suggest targeted multi-omics investigations in a large cohort to improve our understanding of the role of male contributory factors in iRPL.

In vitro fertilization-embryo transfer in patients with unexplained recurrent pregnancy loss

Background:

Empiric therapy for patients with unexplained recurrent pregnancy loss (URPL) is not precise. Some patients will ask for assisted reproductive technology due to secondary infertility or advanced maternal age. The clinical outcomes of URPL patients who have undergone in vitro fertilization-embryo transfer (IVF-ET) require elucidation. The IVF outcome and influencing factors of URPL patients need further study.

Methods:

A retrospective cohort study was designed, and 312 infertile patients with URPL who had been treated during January 2012 to December 2015 in the Reproduction Center of Peking University Third Hospital were included. By comparing clinical outcomes between these patients and those with tubal factor infertility (TFI), the factors affecting the clinical outcomes of URPL patients were analyzed.

Results:

The clinical pregnancy rate (35.18% vs. 34.52% in fresh ET cycles, P = 0.877; 34.48% vs. 40.27% in frozen-thawed ET cycles, P = 0.283) and live birth rate (LBR) in fresh ET cycles (27.67% vs. 26.59%, P = 0.785) were not significantly different between URPL group and TFI group. URPL group had lower LBR in frozen-thawed ET cycles than that of TFI group (23.56% vs. 33.56%, P = 0.047), but the cumulative LBRs (34.69% vs. 38.26%, P = 0.368) were not significantly different between the two groups. The increased endometrial thickness (EMT) on the human chorionic gonadotropin day (odds ratio [OR]: 0.848, 95% confidence interval [CI]: 0.748–0.962, P = 0.010) and the increased number of eggs retrieved (OR: 0.928, 95% CI: 0.887–0.970, P = 0.001) were protective factors for clinical pregnancy in stimulated cycles. The increased number of eggs retrieved (OR: 0.875, 95% CI: 0.846–0.906, P < 0.001), the increased two-pronucleus rate (OR: 0.151, 95% CI: 0.052–0.437, P < 0.001), and increased EMT (OR: 0.876, 95% CI: 0.770–0.997, P = 0.045) in ET day were protective factors for the cumulative live birth outcome.

Conclusion:

After matching ages, no significant differences in clinical outcomes were found between the patients with URPL and the patients with TFI. A thicker endometrium and more retrieved oocytes increase the probability of pregnancy in fresh transfer cycles, but a better normal fertilization potential will increase the possibility of a live birth.

DNA methylation defects in spermatozoa of male partners from couples experiencing recurrent pregnancy loss

STUDY QUESTION

What is the sperm DNA methylation status of imprinted genes in male partners from couples experiencing recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

Aberrations in sperm DNA methylation status of several imprinted genes, such as insulin like growth factor-2-H19 differentially methylated region (IGF2-H19 DMR), intergenic differentially methylated region (IG-DMR), mesoderm specific transcript (MEST), zinc finger protein which regulates apoptosis and cell cycle arrest (ZAC), DMR in intron 10 of KCNQ1 gene (KvDMR), paternally expressed gene 3 (PEG3) and paternally expressed gene 10 (PEG10), as well as decreased sperm global 5-methylcytosine (5mC) levels, are associated with RPL.

WHAT IS KNOWN ALREADY

RPL is defined as loss of two or more pregnancies, affecting 1-2% of couples of reproductive age. Although there are several maternal and paternal aetiological factors contributing to RPL, nearly 50% of the cases remain idiopathic. Thus, there is a need to identify putative paternal factors that could be contributing towards pregnancy loss in cases of idiopathic RPL.

STUDY DESIGN, SIZE, DURATION

In this case-control study, 112 couples undergoing RPL with no identifiable cause were recruited from September 2015 to May 2018. The control group comprised of 106 healthy proven fertile couples with no history of infertility or miscarriage.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In this study, we investigated the paternal genetic and epigenetic factors that could be associated with RPL. We studied DNA methylation, by pyrosequencing, of selected imprinted genes implicated in embryo development, such as IGF2-H19 DMR, IG-DMR, MEST, ZAC, KvDMR, PEG3, PEG10 and small nuclear ribonucleoprotein polypeptide N (SNRPN) in sperm of men whose partners present RPL. Global DNA methylation in sperm was evaluated by studying 5mC content and long interspersed nuclear element 1 (LINE1) promoter methylation. We also studied polymorphisms by pyrosequencing in the IGF2-H19 DMR as well in the IGF2 promoter in both groups.

MAIN RESULTS AND THE ROLE OF CHANCE

In the RPL group, we found a significant decrease in the global sperm 5mC levels and significant decrease in DNA methylation at three CpG sites in LINE1 promoter. For IGF2-H19 DMR and IG-DMR, a significant decrease in sperm DNA methylation at specific CpG sites was observed in RPL group. For maternally imprinted genes like MEST, ZAC, KvDMR, PEG3 and PEG10 hypermethylation was noted. Polymorphism studies for IGF2-H19 DMR and IGF2 revealed significant differences in the genotypic frequencies in males.

LIMITATIONS, REASONS FOR CAUTION

In this study, we analysed the methylation levels of selected candidate imprinted genes implicated in embryo development. Detection of methylation changes occurring at the genome-wide level may reveal further candidate genes having a better distinction between the control and study groups.

WIDER IMPLICATIONS OF THE FINDINGS

Our study demonstrates that certain polymorphisms and aberrant sperm methylation status in imprinted genes are associated with RPL and could contribute to the aetiology of RPL. This study suggests that investigation of paternal genetic and epigenetic factors could be useful in identification of possible causes of idiopathic RPL.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Department of Science and Technology-Science and Engineering Research Board (EMR/2014/000145) and National Institute for Research in Reproductive Health intramural funds (RA/872/01-2020). All authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

The relationship between semen factors and unexplained recurrent spontaneous abortion

BACKGROUND

The male factor may contribute to unexplained recurrent spontaneous abortion (URSA). The relationship between semen factors and URSA is largely unknown. The analysis of metabolomics which is broadly acknowledged as the omics closest to the phenotype is suitable for providing assistance in the semen parameters analysis.

METHODS

We conducted a study including couples with URSA and controls which was next combined with a meta-analysis, and finally the study included 2352 subjects on semen parameters and URSA. Metabolomics analysis was conducted to detect semen metabolic factors related to URSA in total of 106 samples including seminal plasma and sperm cells.

RESULTS

The URSA group had significantly lower total sperm count, sperm concentration, motility and normal morphology percentage. Meta-analysis next showed consistent findings. Metabolomics revealed that 4 metabolites and one pathway and 8 metabolites and one pathway were significantly associated with URSA in sperm and seminal plasma, respectively. The combination of ascorbic acid and guanine in seminal plasma and hexadecanedioic acid and pyroglutamic acid in sperm showed ability for URSA prediction.

CONCLUSION

We provided novel insights into semen indices in relation to URSA. Lower sperm number and quality might increase the risk of URSA, and oxidative stress and hormone metabolism in sperm as well as nucleic acid synthesis and oxidative stress in seminal plasma were related to URSA.

Impact of sperm characteristics on time-lapse embryo morphokinetic parameters and clinical outcome of conventional in vitro fertilization

BACKGROUND

Sperm abnormalities may negatively affect embryo development.

OBJECTIVES

To determine the influence of sperm abnormalities (morphology, motility, DNA fragmentation) on embryo morphokinetic variables and clinical outcome of conventional IVF.

MATERIALS AND METHODS

Participants were 86 couples undergoing in vitro fertilization (IVF). Sperm morphology was evaluated according to the strict criteria proposed by Kruger/Tygerberg. CASA system was applied for sperm motility assessment. Sperm DNA fragmentation was assessed by the chromatin structure assay (SCSA). Morphokinetic parameters were determined in 223 embryos obtained from conventional IVF only and cultured in a single-step medium using time-lapse imaging technology.

RESULTS

Time-lapse variables from the initial embryo development, such as time of pronuclei fading (tPNf) and time for two cells (t2), were those more strongly related with abnormalities of sperm motility, morphology, and DNA fragmentation. Sperm morphological abnormalities rather than sperm motility were more closely associated with embryo morphokinetics. Sperm head defects were mainly correlated with the last stages of embryonic development (t9 to tHB), sperm midpiece defects with intermediate cleaving embryos (t5-t9), and sperm tail defects with the initial stages of embryonic development (tPNa-t4). Excess residual cytoplasm was positively correlated with all embryo morphokinetic parameters except t2 and tM. Absence of acrosomes, pinheads, coiled tails, and multiple sperm morphological defects correlated negatively with time-lapse embryo morphokinetic variables.

DISCUSSION

A large number of sperm-related variables, including frequency of specific morphological defects, morphological indexes, DNA fragmentation and motility, and time-lapse embryo variables, such as time intervals based mainly of 15 time points were recorded.

CONCLUSION

There were strong associations between specific sperm defects of the head, midpiece, and tail with certain stages of embryonic development from observation of pronuclei to the hatched blastocyst. Coiled tail, cumulative head defects, and multiple abnormalities index (MAI) were associated both with embryo morphokinetics and the implantation success.

Quantitative proteomics decodes clusterin as a critical regulator of paternal factors responsible for impaired compensatory metabolic reprogramming in recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a perplexing problem experienced with two or more consecutive miscarriages wherein the cause remains unexplained in >50% of cases. However, despite several evidences of involvement of paternal factors on early embryogenesis and placental development, its contribution towards RPL has been largely unexplored. There is augmented lipid peroxidation, protein carbonylation, thionylation and enhanced histone retention in spermatozoa of RPL patients. Differentially expressed proteins in the spermatozoa of RPL patients may contribute towards aberrant embryo development and pregnancy loss. The present study comprised of male partners of RPL patients (n = 16) with the absence of any female factor abnormality and age-matched fertile healthy donors (n = 20). Pooled sperm samples from each group were subjected to high-throughput liquid chromatography-tandem mass spectrophotometry (LC-MS/MS) and subsequent bioinformatic analysis that identifies key proteins to be differentially expressed (DEPs). A total of 23 DEPs were identified with ≥2.0 fold change were considered to be significant. A key finding of the study was clusterin (CLUS), a predominant oxidative stress protein that takes part in an array of pre- and post-fertilisation molecular processes, found to be underexpressed as it was confirmed by Western blot analysis. This pilot study supports contributions of paternal oxidative predominance in RPL and encourages further investigation.

Evaluating the role of paternal factors in aetiology and prognosis of recurrent pregnancy loss: study protocol for a hospital-based multicentre case-control study and cohort study (REMI III project)

INTRODUCTION

Recurrent pregnancy loss (RPL) is defined as the spontaneous demise of two or more pregnancies before the fetus reaches viability. Despite investigation of multiple known maternal risk factors, in more than 50% of couples, this condition remains unexplained. Studies focusing on paternal factors in RPL are scarce, and therefore, paternal evaluation in RPL is currently very limited. However, regarding single miscarriage, there are multiple publications suggesting a contributive role of paternal factors. In this project, we aim to identify paternal factors associated with RPL and to improve couple-specific prediction of future pregnancy outcomes by developing a prediction model containing both maternal and paternal factors.

METHODS AND ANALYSIS

In a case-control design, the relation between unexplained RPL and paternal age, lifestyle factors, sperm DNA damage and immunomodulatory factors in peripheral blood and semen will be studied. Prospectively, 135 couples with naturally conceived unexplained RPL (cases) and 135 fertile couples without a history of pregnancy loss (controls) will be included, with collection of paternal blood and semen samples and documentation of clinical and lifestyle characteristics. In addition, 600 couples from both groups will be included retrospectively. To adjust for confounders, multivariate logistic regression will be used. The predictive value of paternal and maternal factors will be studied in the total RPL cohort consisting of approximately 735 couples. The primary outcome of the cohort study is live birth within 5 years after initial visit of the clinic. Secondary outcomes are ongoing pregnancy, time interval until next pregnancy and pregnancy complications.

ETHICS AND DISSEMINATION

This project is approved by the Medical Research Ethics Committee of the Leiden University Medical Center. No risks or burden are expected from the study. The findings of this study will be disseminated via peer-reviewed publications and presentations at international conferences.

TRIAL REGISTRATION NUMBER

NL7762.

Microdeletion of Y chromosome as a cause of recurrent pregnancy loss

CONTEXT:

In majority of couples experiencing recurrent pregnancy loss (RPL), etiology is still unknown. Two genetic factors have been suggested to underlie miscarriage in a subset of patients, namely skewed X chromosome inactivation in females and Y chromosome microdeletions in their partners. In males, microdeletions of the Y chromosome are known to cause spermatogenetic failure and male infertility.

AIMS:

The aim of the study was to find out the role of Y chromosome microdeletion in male partners of couples experiencing RPL.

SETTINGS AND DESIGN:

University hospital and genetic laboratory. Prospective case–control study.

SUBJECTS AND METHODS:

59 couples with a history of RPL and 20 fertile controls (FC) with no miscarriage were included in the study. The study subjects were divided into male partners of RPL couples with abnormal semen parameters (AS) (n = 8), and couples with normal semen parameters (NS) (n = 51). Fertile controls with normal semen parameters were (FC) (n = 20). Y chromosome microdeletion was performed on 40 male partners of RPL and 20 FC.

STATISTICAL ANALYSIS USED:

Chi-square test. P <0.05 were considered statistically significant.

RESULTS:

13 of the 40 RPL cases showed deletion in three azoospermia factor loci on the long arm of Y chromosome. The P value was significant with Y chromosome microdeletion in RPL cases as compared to 20 FC where no Y chromosome microdeletion was present.

CONCLUSIONS:

Y chromosome microdeletion may be an important hidden cause of recurrent pregnancy miscarriage and can be offered to couples with the undiagnosed cause of miscarriage.

Positive association of sperm dysfunction in the pathogenesis of recurrent pregnancy loss

BACKGROUND

Recurrent pregnancy loss (RPL) is one of the most frustrating and difficult areas in reproductive medicine, because the aetiology is often unknown and there are few evidence-based diagnostic and treatment strategies. RPL diagnosis is mainly focused on the female partner. The male factor contributing in evaluation of RPL has been less investigated, it is restricted to karyotype and basic semen analysis, assessment of functionality of sperm is largely ignored.

AIM AND OBJECTIVE

To investigate the role of sperm factors in RPL through regular semen analysis preceded with sperm function tests.

MATERIALS AND METHODS

We performed a case control study of 95 males whose partner has experienced two or more pregnancy loss as case and 37 volunteers who had fathered child/children without the history of RPL as control group. Basic semen analysis and sperm function test (Nuclear chromatin decondensation {NCD}, Hypo osmotic swelling {HOS} and Acrosome intactness test {AIT} was performed. The results were analysed by performing Independent-sample t-test using SPSS (version 14.0).

RESULTS

One individual had anatomical abnormality which was confirmed through trans-rectal ultrasound scanning and RPL group showed statistically significant (p<0.05) value for NCD, HOS and AIT and 36.8% of RPL individuals had reduced score for sperm count and motility. Less than 4% normal morphology was recorded in 16.8% individuals of RPL group.

CONCLUSION

Our study revealed that the positive association of sperm dysfunction in RPL cases, hence male may be considered for a routine part of the evaluation along with his partner in the near future in order to achieve desirable outcome.

Relationship between HLA-G polymorphism and susceptibility to recurrent miscarriage: a meta-analysis of non-family-based studies

PURPOSE

The HLA-G 14-bp insertion/deletion polymorphism had been inconsistently associated with recurrent miscarriage (RM) risk. We examined the association by performing a meta-analysis.

METHODS

Eligible articles were searched in PubMed, EMBASE and CNKI without language limitation. We included all the articles about two or more miscarriages associated with HLA-G 14-bp polymorphism. The odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Statistical analyses were performed by the STATA10.0 software.

RESULTS

17 studies were included, representing 1786 cases and 1574 controls. The current meta-analysis showed that 14-bp polymorphism was not associated with RM risk in all genetic models and allele contrast(+14 bp vs. -14 bp: OR = 1.13; 95% CI, 0.96,1.32; +14 bp/+14 bp vs. -14 bp/-14 bp: OR = 1.16, 95% CI, 0.85, 1.59; +14 bp/-14 bp vs. -14 bp/-14 bp: OR = 1.21, 95% CI, 0.92,1.58; dominant model: OR = 1.33; 95% CI, 0.99,1.78; recessive model: OR = 1.06; 95% CI, 0.79,1.43). Moreover, a significant heterogeneity was evident across studies. On the other hand, the subgroup analysis demonstrated that there was a significant association between HLA-G 14-bp polymorphism and patients with three or more miscarriages(+14 bp vs. -14 bp: OR = 1.27; 95% CI, 1.04, 1.55; dominant model: OR = 1.52; 95% CI, 1.16, 1.99; and model +14 bp/-14 bp versus -14 bp/-14 bp: OR = 1.51; 95% CI, 1.15, 1.97;).

CONCLUSIONS

Our comprehensive meta-analysis indicated that there was insufficient evidence to demonstrate a conclusive association between the HLA-G 14-bp insertion/deletion polymorphism and the risk of RM. But HLA-G 14-bp insertion/deletion polymorphic variation was associated with RM risk in patients with three or more miscarriages. Larger and well-designed studies may eventually provide a better, comprehensive understanding of the association between the HLA-G 14-bp insertion/deletion polymorphism and RM in the future.

Sperm chromatin integrity may predict future fertility for unexplained recurrent spontaneous abortion patients

The pathogenesis of recurrent spontaneous abortion (RSA) is multi-factorial, complex and poorly understood. In the present study, semen parameters, including sperm chromatin integrity, sperm concentration, sperm motility and sperm morphology, were compared between 111 men whose partners had a history of unexplained RSA (RSA group) and 30 healthy fertile men (control group). The RSA group was further separated into three subgroups, depending on their reproductive outcome during the 12 months after they were enrolled in the study: the pregnancy subgroup consisted of 43 men whose partners achieved a successful pregnancy up to at least the 24th week of gestation; the abortion subgroup included 31 men whose partners experienced further abortions; and the infertile subgroup had 37 men whose partners did not have any positive pregnancy test after regular, unprotected intercourse. Significantly lower proportion of sperm with normal morphology was found in the abortion subgroup (14.7 ± 4.3%) than in the control group (17.5 ± 5.0%). Sperm concentrations were significantly lower in the infertile subgroup (55.7 ± 24.1%) than in the controls (68.6 ± 27.8%). The rates of abnormal sperm chromatin integrity were significantly higher in the abortion (16.7 ± 7.7%) and infertile (16.3 ± 6.6%) subgroups, compared to the control group (13.0 ± 4.4%). Logistic regression analysis showed that the subsequent reproductive outcome of the 111 RSA patients was negatively correlated to the rates of abnormal sperm chromatin integrity. In conclusion, sperm chromatin integrity, sperm morphology, and sperm concentration were associated with future reproductive outcome of RSA patients. The sperm chromatin integrity was a significant predictor for future abortion and infertility.

Semen parameters and sperm DNA fragmentation as causes of recurrent pregnancy loss

OBJECTIVES

To evaluate and compare standard sperm parameters, and sperm DNA fragmentation in seminal ejaculates from men whose partners had a history of recurrent pregnancy loss (RPL) and in a control group of men who had recently established their fertility.

METHODS

Semen samples from 31 patients with a history of recurrent pregnancy loss and 20 men with proven fertility were analyzed according to World Health Organization guidelines. Sperm DNA fragmentation was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay.

RESULTS

When sperm quality of the control group was compared with that of the RPL group, a significant difference was observed in sperm motility, but not in other parameters. The mean number of sperm cells with fragmented DNA was significantly increased in the RPL group (32.22 ± 6.14%) compared with control donors (10.20 ± 2.1%).

CONCLUSIONS

Our data indicate that sperm from men with a history of RPL have a higher incidence of DNA damage and poor motility than sperm from a control group, and this can explain in part the pregnancy loss in these patients.

Evaluation of sperm's chromatin quality with acridine orange test, chromomycin A3 and aniline blue staining in couples with unexplained recurrent abortion

OBJECTIVE

To evaluate the sperm's chromatin quality in couples with spontaneous recurrent abortion.

METHODS

Thirty couples with spontaneous recurrent abortion (case group) and 30 fertile couples (control group) referring to Zeinabieh Gynecology clinic of Shiraz were included. Semen samples were collected for each participant and were used for standard semen analysis and sperm nuclear maturity tests including Chromomycin A3 (CMA3), Aniline Blue (AB) staining and Acridine Orange (AO) test (by light microscopy).

RESULT

Patients in case group had significantly higher percentage of CMA3 (p < 0.001) and AB (p < 0.001) positive spermatozoa compared to controls. However AO results did not differ significantly between groups (p = 0.656). Sperm morphology and progressive motility were negatively correlated with CMA3 (p = 0.001 and p = 0.043) and AB (p = 0.015 and p = 0.031) respectively.

CONCLUSION

Evaluation of the sperm's quality via CMA3 and AB staining could be considered as one of the complementary tests of semen analysis for assessment of male factor in couples with spontaneous recurrent abortion.

Is abnormal sperm function an indicator among couples with recurrent pregnancy loss?

OBJECTIVE

To determine whether or not sperm function parameters are altered in male partners of couples with a history of idiopathic recurrent pregnancy loss (RPL).

DESIGN

In comparison with proven fertile volunteers, sperm function parameters like hypo-osmotic swelling (HOS), acrosomal status (AS), and nuclear chromatin decondensation (NCD) were assessed in vitro from male partners of couples with a history of idiopathic RPL.

SETTING

Infertility clinic and andrology laboratory at National Institute of Health and Family Welfare.

PATIENT(S)

Male partners of couples with a history of idiopathic RPL and proven fertile male volunteers (control).

INTERVENTION(S)

Standard semen analysis, assessment of sperm morphology, and sperm function with tests such as HOS, AS, and NCD.

MAIN OUTCOME MEASURE(S)

Sperm paameters, such as HOS, AS, and NCD, were assessed in semen samples from RPL in comparison with the proven fertile control group.

RESULT(S)

Semen samples from the idiopathic RPL group showed below normal test scores in 57.1% of the cases for all three sperm parameters. The highest aberration (83% of cases) in sperm attributes was observed in NCD, followed by AS (45.7%) and HOS (42.9%). In contrast, abnormality in sperm morphology was limited to 5.7% of the cases. Subnormal sperm function is directly proportional with subnormal sperm motility (<50%) in 23% of the cases. Even in semen samples with normal sperm motility, sperm function scores were below normal in 31.4% of the RPL group.

CONCLUSION(S)

Reduction in test scores of sperm function, like HOS, AS, and NCD, in male partners of couples with idiopathic RPL suggests that sperms with altered or lowered functional competencies, if they fertilize the oocytes, may lead to the development of an unsustainable embryo resulting in early pregnancy loss. Normal sperm motility does not always ensure normal sperm function scores.

The impact of male factor on recurrent pregnancy loss

PURPOSE OF REVIEW

The present paper reviews the current literature on the impact of male factor on recurrent pregnancy loss.

RECENT FINDINGS

Most clinicians focus their evaluation of recurrent pregnancy loss on the female, without much, if any, consideration of the other half of the couple - the male. Yet, the male contributes one-half of the genes for the embryo. Recent literature demonstrates that the male contributes to recurrent pregnancy loss due to genetic factors, semen factors or due to other factors such as age.

SUMMARY

Recurrent pregnancy loss results as a factor of a couple. This paper emphasizes the contribution of the male to implantation failure, miscarriage, and congenital anomalies suggested by recent literature. The current data are preliminary. With further investigation, evaluation of the male may be considered a routine part of the evaluation in the near future.

Sperm aneuploidy and recurrent pregnancy loss

Experiments of double target in-situ hybridization were performed separately for chromosomes 1-17, 8-18 and sex chromosomes on sperm samples from 20 couples suffering from three or more recurrent first trimester abortions. For a subset of this study population, additional experiments of multicolour fluorescence in-situ hybridization for chromosomes 4, 7, 12, 13, 15, 18, 21, and 22, were performed on the bases of the available data from abortive tissue karyotyping. A markedly high rate of sperm disomy (14.5-15.5%) was scored in only two cases. For three other patients, the cumulative disomy rates for chromosomes 1, 17, 8, 18, X and Y also increased but at a lower level (7.8-9.5%). For the remaining 15 patients, the frequency of sperm aneuploidy was moderately increased or normal. Men with recurrent pregnancy loss (RPL) and poor semen quality had baseline sperm aneuploidy and diploidy rates higher than men with normal semen parameters (with or without RPL). Using probes for chromosomes 1, 17, 8, 18, X and Y, significantly elevated frequencies of sperm aneuploidy (not diploidy) were found in 10% of men with a history of RPL. Their rate of sperm aneuploidy was 30-34%. For the other men, changes in sperm aneuploidy were not thought to affect RPL. Poor semen quality per se impacted negatively on sperm aneuploidy and diploidy, thus making the interpretation of clinical data more difficult.

Sperm DNA fragmentation is increased in couples with unexplained recurrent pregnancy loss

Previous studies have indicated that sperm quality may be related to unexplained recurrent pregnancy loss. This study evaluated the degree of sperm DNA fragmentation using the TUNEL assay on sperm from 24 couples with unexplained recurrent pregnancy loss (RPL) compared to sperm from 2 control groups: donors of known fertility and unscreened men from the general population. The percentage of sperm staining positive for DNA fragmentation was increased (p < .001) in the RPL group (38 +/- 4.2) compared to the donor (11.9 +/- 1.0) or general population (22 +/- 2.0) control groups. In the RPL group, no correlation was observed between semen quality parameters and the TUNEL data. These data indicate that some RPL patients have a significant increase of sperm DNA fragmentation, which may be causative of pregnancy loss in some patients.

Implications of sperm chromosome abnormalities in recurrent miscarriage

PURPOSE

Our purpose was to assess the existence of sperm chromosome abnormalities in recurrent pregnancy loss in an assisted reproduction program.

METHODS

In this prospective study, 12 sperm samples from couples undergoing in vitro fertilization with two or more first-trimester spontaneous abortions were analyzed. Diploidy and disomy in decondensed sperm nuclei were assessed for chromosomes 13, 18, 21, X, and Y using two- and three-color fluorescence in situ hybridization.

RESULTS

Sex chromosome disomy in sperm samples from recurrent abortion couples was significantly increased compared to that from internal controls (0.84% vs 0.37%). In a subpopulation of seven couples who underwent oocyte donation, mean frequencies for sex chromosome disomy (1%) were even higher and diploidy (0.43%) was also significantly increased.

CONCLUSIONS

These results suggest an implication of sperm chromosome abnormalities in some cases of recurrent pregnancy loss.

The hypo-osmotic swelling test in recurrent miscarriage

OBJECTIVE

To determine whether there is any association between sperm membrane integrity as determined by the hypo-osmotic swelling test score and unexplained recurrent miscarriage.

DESIGN

Prospective observational study.

SETTING

Tertiary referral center for recurrent miscarriage.

PATIENT(S)

Semen samples from 20 male partners of women who had had three or more first trimester miscarriages of unexplained etiology and semen samples from 20 prospective semen donors of unknown fertility potential.

MAIN OUTCOME MEASURE(S)

Sperm density, sperm motility, sperm morphology, and hypoosmotic swelling test score.

RESULT(S)

There was no difference in the median sperm density, the mean sperm motility, or the mean sperm morphology between the two groups. However, the recurrent miscarriage group had a significantly lower hypo-osmotic swelling test score than the control group.

CONCLUSION(S)

The hypo-osmotic swelling test score is significantly lower in samples from men whose partners have had unexplained recurrent spontaneous abortions. With the exception of cytogenetic abnormalities in peripheral blood karyotype, this is the first study to identify a male factor component in recurrent miscarriage.