Embryo development, pregnancy and twin delivery after microinjection of 'stump' spermatozoa

Insight on multiple morphological abnormalities of sperm flagella in male infertility: what is new?

The syndrome of multiple morphological abnormalities of the sperm flagella (MMAF) is a specific kind of asthenoteratozoospermia with a mosaic of flagellar morphological abnormalities (absent, short, bent, coiled, and irregular flagella). MMAF was proposed in 2014 and has attracted increasing attention; however, it has not been clearly understood. In this review, we elucidate the definition of MMAF from a systematical view, the difference between MMAF and other conditions with asthenoteratozoospermia or asthenozoospermia (such as primary mitochondrial sheath defects and primary ciliary dyskinesia), the knowledge regarding its etiological mechanism and related genetic findings, and the clinical significance of MMAF for intracytoplasmic sperm injection and genetic counseling. This review provides the basic knowledge for MMAF and puts forward some suggestions for further investigations.

Successful intracytoplasmic sperm injection with testicular spermatozoa from a man with multiple morphological abnormalities of the sperm flagella: a case report

PURPOSE

The purpose of this study is to analyze the sperm morphology of a Chinese man affected with multiple morphological abnormalities of the sperm flagella (MMAF) and observe the intracytoplasmic sperm injection (ICSI) outcome.

METHODS

A Chinese man was diagnosed with multiple morphological abnormalities of the sperm flagella by semen analysis and electron microscopy. Testicular spermatozoa were injected intracytoplasmically, and the following ICSI results were observed.

RESULTS

All the spermatozoa from his ejaculate were immotile and morphologically abnormal in the flagellum. In transmission electron microscopy assays, most spermatozoa showed disorganized fibrous sheath, accompanied by distortion of various cytoskeletal components, and missing of the central pair microtubules. Testicular sperm was injected to the oocytes in two ICSI cycles, with fertilization rates of 45.5 and 40.0%. Finally, a healthy female infant was delivered at the second ICSI cycle.

CONCLUSIONS

Fertilization and pregnancy could be achieved by intracytoplasmic sperm injection, regardless of severe flagellar defects. ICSI is effective for MMAF-affected man, and testicular sperm is an alternative when no motile sperm is available.

Pregnancy and birth after intracytoplasmic sperm injection with normal testicular spermatozoa in a patient with azoospermia and tail stump epididymal sperm

MAIN FINDINGS

An intriguing yet perplexing case report of a successful pregnancy and live birth with intracytoplasmic sperm injection using normal testicular sperm, after the finding of azoospermia in the semen analysis and discovering only tail stump abnormal sperm in the epididymis. Case hypothesis: A tail stump sperm defect of genetic origin was suspected. However, after obtaining normal testicular sperm we concluded that obstructive azoospermia, either idiopathic or secondary to multiple minor genital trauma was the plausible scenario. This has rendered the search of previous reports on a similar condition, but none was found. However, it has raised scientific thoughts for future research. Promising future implications: The importance of reporting this case is to alert urologists performing sperm retrieval that healthy and morphologically normal sperm may be found in the testis of azoospermic men with 100% tail stump epididymal sperm. Retrieval of normal testicular sperm obviates the need of a more complex investigation, including sperm electron microscopy. It also offers the possibility of utilizing such gametes for sperm injections rather than abnormal tail stump sperm that may be associated with a poor reproductive outcome.

Tales of the tail and sperm head aches: changing concepts on the prognostic significance of sperm pathologies affecting the head, neck and tail

This article presents an update on the variable prognostic significance of different sperm pathologies in patients with severe male factor infertility due to morphology and motility disorders. Severe asthenozoospermia is one of the leading causes of male infertility as spermatozoa cannot reach the oocyte and/or penetrate normally. Identifying structural causes of sperm immotility was of great concern before the advent of intracytoplasmic sperm injection (ICSI), because immotility was the limiting factor in the treatment of these patients. In these cases, in vitro methods are used to identify live spermatozoa or stimulate sperm motility to avoid selection of non-viable cells. With these advances, fertilization and pregnancy results have improved dramatically. The identification of genetic phenotypes in asthenozoospermia is important to adequately inform patients of treatment outcomes and risks. The one sperm characteristic that seriously affects fertility prognosis is teratozoospermia, primarily sperm head and neck anomalies. Defects of chromatin condensation and acrosomal hypoplasia are the two most common abnormalities in severe teratozoospermia. The introduction of microscopic methods to select spermatozoa and the development of new ones to evaluate sperm quality before ICSI will assure that ultrastructural identification of sperm pathologies will not only be of academic interest, but will also be an essential tool to inform treatment choice. Herein, we review the differential roles played by sperm components in normal fertilization and early embryo development and explore how assisted reproductive technologies have modified our concepts on the prognostic significance of sperm pathologies affecting the head, neck, mid-piece and tail.

Tail stump syndrome associated with chromosomal translocation in two brothers attempting intracytoplasmic sperm injection

OBJECTIVE

To raise the possibility that a familial chromosomal translocation associated with teratozoospermia can disrupt a gene necessary for flagellum assembly.

DESIGN

Case report.

SETTING

University hospital.

PATIENT(S)

Two brothers with infertility related to anomalies of meiotic division and of the flagella assembly, presenting the same balanced 5-12 autosomal translocation.

INTERVENTION(S)

Several intracytoplasmic sperm injection (ICSI) cycles in our IVF department for both couples.

MAIN OUTCOME MEASURE(S)

Sperm analysis, karyotypes, electron microscopy, and fluorescence in situ hybridization (FISH) analysis of spermatozoa performed using probes coding for chromosomes X, Y, 13, 18, and 21.

RESULT(S)

In both brothers, sperm analysis indicated a tail stump syndrome. Electron microscopy analysis displayed complex abnormalities, which were probably related to meiotic errors. The FISH analysis indicated an increase of diploid germ cells. Karyotypes of both patients revealed the same balanced chromosomal t(5;12) (p15.1; q21) translocation. Results of ICSI cycles were comparable for both couples. A twin pregnancy was achieved in one of these two couples, but a spontaneous miscarriage occurred at 10 weeks of gestation.

CONCLUSION(S)

The flagella anomalies raise the possibility that the translocation disrupts a gene necessary for the flagellum assembly, although a mutation in a gene unrelated to the chromosome breakpoints cannot be excluded.

Outcome of ICSI with ejaculated spermatozoa in a series of men with distinct ultrastructural flagellar abnormalities

BACKGROUND

Severe sperm motility impairment results in human infertility, which can be overcome by ICSI. Whether some particular, possibly genetic, flagellar abnormalities can influence embryonic development is a matter of debate.

METHODS

Analysis of ultrastructural flagellar abnormalities and ICSI outcomes with ejaculated spermatozoa in a series of 21 infertile patients with asthenozoospermic or dyskinetic spermatozoa due to a primary and specific flagellar abnormality was carried out.

RESULTS

Patients were sorted into six categories according to flagellar ultrastructural defects. Oocyte fertilization occurred in the 21 couples with a mean 2PN fertilization rate reaching 61.85%. No difference was observed in the kinetics of in vitro development or in the morphological quality of the embryos between the different types of flagellar abnormalities. Pregnancy occurred in 12 couples (57.1%) and delivery in nine couples (42.86%). Both the implantation rate and the clinical pregnancy rate per cycle were lower in type III abnormalities and in patients with an initial sperm motility less than 5%.

CONCLUSIONS

The rate of ICSI success may be influenced by the type of flagellar abnormality. ICSI provides a suitable solution for patients with sperm flagellar defects but raises the question of the consequences of a specific (and primary flagellar) abnormality on oocyte fertilization, on embryo and fetal development as well as on live birth.

Fluorescence in situ hybridization and molecular studies in infertile men with dysplasia of the fibrous sheath

OBJECTIVE

To perform fluorescence in situ hybridization (FISH) and molecular analysis in patients with the genetic sperm defect "dysplasia of the fibrous sheath" (DFS).

DESIGN

Retrospective study.

SETTING

Regional Referral Center for Male Infertility, Siena, Italy.

PATIENT(S)

Twelve infertile patients with DFS sperm defects.

INTERVENTION(S)

Family history, lymphocytic karyotype, physical and hormonal assays, semen analysis.

MAIN OUTCOME MEASURE(S)

The DFS sperm phenotype was defined by light, fluorescent, and electron microscopy. Sperm chromosomal constitution was examined by FISH. Gene deletions were tested by polymerase chain reaction.

RESULT(S)

The genetic sperm defect DFS was determined by transmission and scanning electron microscopy. Immunofluorescence staining of A-kinase anchoring protein 4 (AKAP4) showed a moderate and diffuse signal, revealing a disorganized and incompletely assembled fibrous sheath. In 11 of 12 DFS patients, polymerase chain reaction for detecting the presence of partial sequence of AKAP4/AKAP3 binding regions gave positive results. Fluorescence in situ hybridization was performed in decondensed sperm nuclei with probes for chromosomes 18, X, and Y. The mean disomy frequency of chromosome 18 was in the normal range, whereas the mean disomy frequencies of sex chromosomes and diploidies were twice those of controls.

CONCLUSION(S)

These results should be considered when DFS sperm are used in assisted reproductive technology, owing to the high risk of transmission of chromosomal unbalance and of DFS sperm defects to male offspring.

Morphological and morphometric attributes of epididymal and testicular spermatozoa following surgical sperm retrieval for obstructive and nonobstructive azoospermia

Whilst the morphological (shape) and morphometric (sperm head size) attributes of ejaculated spermatozoa have been well studied, the morphological and morphometric qualities of testicular and epididymal spermatozoa retrieved from males with obstructive and nonobstructive azoospermia is much less documented. We wished to examine the effect of aetiology of azoospermia and site of retrieval on the attributes of retrieved spermatozoa. This was a prospective observational study of 30 consecutive successful sperm retrievals, six for nonobstructive azoospermia and 24 for obstructive, of which five were retrieved from the epididymis and the remainder from the testis. The proportion of morphologically normal testicular spermatozoa in patients with obstructive and nonobstructive azoospermia was not significantly different (7% versus 7.6%, P = 0.97). Testicular spermatozoa from males with obstructive azoospermia showed an increase in frequency of sperm with small heads [47/180 (26%) versus 97/909 (11%), P = 0.036] as well as small acrosome and increasing vacuole formation over nonobstructive spermatozoa. Similarly, there was a significant increase in tail deformities and decreases in tail lengths in sperm from males with nonobstructive azoospermia. Epididymal spermatozoa showed significantly greater proportion of morphologically normal spermatozoa than testicular (20% versus 13%, P = 0.001) as well as a significant increase in acrosome vacuoles. Furthermore, morphometrically epididymal spermatozoa displayed with smaller head length, width and area than testicular spermatozoa. Testicular spermatozoa from obstructive azoospermia displayed significantly less tail defects (35% versus 57%, P = 0.003) as well as significantly longer tail lengths (30.6 microm versus 10.7 microm). These morphological and morphometric differences between epididymal and testicular and obstructive and nonobstructive spermatozoa may represent part of the natural maturation process. There were no associations between any morphological or morphometric abnormality with any significant parameter in subsequent use in ICSI.