Clinical, genetic and cytogenetic studies in couples attending an infertility clinic

The present study was carried out in order to assess the genetic component in a group of sterile or infertile couples from a latin american population. During a six-year-period, 258 patients were investigated. Sixty two per cent of the cases were studied for sterility and 38% for infertility. It was found that 34% had genetic pathology. In infertile couples the frequency of chromosome abnormalities was 2.8%; when sterility was also considered this frequency was 11.6%. Chromosome variants were found in 11.4% of the sterile patients and in 8.8% of the infertile cases.     

Chromosome studies in 2136 couples with spontaneous abortions

Summary Two thousand one hundred and thirty six couples with one or more spontaneous abortions (SAB) before 13 weeks of gestation and with or without one normal liveborn child (NLC) were karyotyped. In 4.31% of the couples one partner was a carrier of a major chromosomal abnormality. Couples with SAB only have 2-fold more chromosomal aberrations than couples with SAB and NLC. A correlation between the frequency of chromosomal abnormalities and the number of SAB was observed. Finally, the various types of chromosome aberrations were analysed.     

Bilan des examens chromosomiques de 277 couples candidats à l’injection intracytoplasmique de spermatozoïde

In these study the frequency of congenital chromosomal aberrations was assessed in a sample of 277 couples included in a intracytoplasmic sperm injection (ICSI) program. A total of 7 aberrant karyotypes were diagnosed, corresponding to an abnormality rate of 1.3% per individual and 2.6% per couple. The following types of abnormalities were observed: reciprocal translocations (n=2), Robertsonian translocations (n=2), pericentral inversion (n=1), sex chromosomal mosaicism (n=1), marker chromosome (n=1). Surprisingly, 71% (5/7) of all abnormal karyotypes were contributed by the female partner of ICSI patients. These data confirm the higher incidence of chromosomal aberration in infertile couples compared with the baseline population risk. It also confirms that not only the male, but also the female should be routinely karyotyped prior to ICSI, and then receive appropriate genetic counselling.     

A cytogenetic study of couples with recurrent spontaneous abortions and infertile patients with recurrent IVF/ICSI failure

PURPOSE:

This study was conducted to determine the frequency and contribution of chromosomal abnormalities in miscarriages and in couples with recurrent in vitro fertilization/intra cytoplasmic sperm injection (IVF/ICSI) failure.

MATERIALS and METHODS:

A total of 221 individuals; 79 with three or more recurrent spontaneous abortions and 142 with at least three IVF/ICSI failures. Chromosomal analysis from peripheral blood lymphocytes was performed according to standard cytogenetic methods using G-banding technique.

RESULTS:

Abnormal karyotype was found in 21 (9.50%) individuals. Of these 21 subjects, 4 (19.04%) exhibited sex chromosomal abnormalities and 17 (80.96%) had autosomal abnormalities. Male partners had significantly higher chromosomal abnormalities (5.88%) than of females (3.61%). These abnormalities were also higher in patients with recurrent spontaneous abortions than with IVF/ICSI failure (P < 0.05).

CONCLUSIONS:

These data may be indicative that chromosomal abnormalities are involved more in spontaneous abortions than in recurrent IVF/ICSI failure. Cytogenetic analysis could be valuable for these couples when clinical data fail to clarify the cause.     

Chromosomal abnormalities as a cause of recurrent abortions in Egypt

BACKGROUND:

In 4%-8% of couples with recurrent abortion, at least one of the partners has chromosomal abnormality. Most spontaneous miscarriages which happen in the first and second trimesters are caused by chromosomal abnormalities. These chromosomal abnormalities may be either numerical or structural.

MATERIAL AND METHODS:

Cytogenetic study was done for 73 Egyptian couples who presented with recurrent abortion at Genetic Unit of Children Hospital, Mansoura University.

RESULTS:

We found that the frequency of chromosomal abnormalities was not significantly different from that reported worldwide. Chromosomal abnormalities were detected in 9 (6.1%) of 73 couples. Seven of chromosomal abnormalities were structural and two of them were numerical.

CONCLUSION:

Our results showed that 6.1% of the couples with recurrent abortion had chromosomal abnormalities, with no other abnormalities. We suggest that it is necessary to perform cytogenetic in vestigation for couples who have recurrent abortion.     

A cytogenetic study of Kuwaiti couples with infertility and reproductive disorders: short arm deletion of chromosome 21 is associated with male infertility

Chromosomal anomalies may be a reason for both male and female infertility. The aim of this study was to investigate the contribution of chromosomal abnormalities in sterile couples from Kuwait. A total of 118 patients with clinical diagnosis of infertility was analyzed using cytogenetic banding techniques. Common chromosomal abnormalities were detected in 12 patients. We describe here one new case of an infertile male with the karyotype 46,XY, del(21)(pter;q11.2). The overall incidence of 11% abnormality indicates that routine chromosome analysis of infertile couples in Kuwait should be considered before the planning of intracytoplasmic sperm injection.     

Balanced translocations among couples with two or more spontaneous abortions: Are males and females equally likely to be carriers?

Chromosome studies were performed on a series of 177 couples referred for genetic counseling following two or more spontaneous abortions to clarify the relationship between karyotype and fertility in males and females and to provide risk figures for genetic counseling. The results of these investigations, when combined with those in the literature, suggest that 2-3% of individuals in couples experiencing early fetal losses carry a balanced translocation and that this is not markedly influenced by the number of losses greater than two. Females are more likely than males to be the carrier, reflecting the fact that structural abnormalities of the chromosomes that are compatible with fertility in the female may be associated with sterility in the male. Karyotyping should be performed on both members of a couple following two spontaneous abortions and the products of conception should be studied whenever possible to begin to determine the biological basis of the association between parental rearrangement and fetal loss.     

Cytogenetic abnormalities in 222 infertile men with azoospermia and oligospermia in Iran: Report and review

BACKGROUND:

Infertility affects approximately 10%-15% of couples in reproductive age. In half of the couples, causes are male-related, associated with impaired spermatogenesis. There is a complex correlation between genetics and infertility. Several factors affect on gametogenesis, from which factors that lead to chromosomal abnormalities are one of the best known. The aim of this study was to determine type and rate of chromosomal abnormalities in infertile azoospermic and oligospermic males in Iranian population.

MATERIALS AND METHODS:

The records of a total of 222 participants were evaluated retrospectively.

RESULTS:

As a whole we observed 13.96% chromosomal abnormality, from which 12.15% showed numerical and 1.8% showed structural abnormalities.

CONCLUSION:

Comparison of our results with the review of the literature shows a higher incidence (4- fold) of gonosomal, in particular, numerical gonosomal, chromosomal anomalies. Cytogenetic analysis is strongly suggested for infertile men, particularly in those who suffer from azoospermia.     

Chromosome abnormalities in sperm from infertile men with normal somatic karyotypes: oligozoospermia

Recently, intracytoplasmic sperm injection (ICSI) has been extremely successful for the treatment of male infertility. However, transmission of cytogenetic defects to offspring is a great concern. There are two types of cytogenetic problems in patients seeking ICSI; one is the transmission of genetic defects from patients with constitutional chromosomal abnormalities and the second is the generation of de novo defects in infertile men. Generally about 5.1% of infertile men have chromosomal abnormalities. Among such infertile men, men with severe spermatogenesis defects, including oligozoospermia and azoospermia, are subjects for ICSI. Therefore it is very important to obtain cytogenetic information in these infertile patients. Furthermore, oligozoospermic men with a normal somatic karyotype also have increased frequencies of sperm chromosome abnormalities. Oligozoospermia is usually associated with other sperm alterations, for example oligoasthenozoospermia, oligoteratozoospemia and oligoasthenoteratozoospermia. In this review, the relationship between sperm concentration and sperm aneuploidy frequencies has been analyzed. The inverse correlation between the frequency of sperm aneuploidy and concentration has been reported in extensive studies. Especially in severe oligozoospermia, a significantly higher frequency of sex chromosome aneuploidy has been observed and this has been corroborated in recent clinical outcome data of ICSI.     

Is there a relationship between sperm chromosome abnormalities and sperm morphology?

This review explores the relationship between sperm chromosomal constitution and morphology. With the advent of techniques for obtaining information on the chromosome complements of spermatozoa, this relationship has been studied in fertile men and in men with a high frequency of chromosomal abnormalities. Using human sperm karyotype analysis, no relationship between sperm chromosome abnormalities and morphology was found in fertile men, translocation carriers or post-radiotherapy cancer patients. Fluorescence in situ hybridization (FISH) analysis has not generally revealed a specific association between morphologically abnormal sperm and sperm chromosome abnormalities, but has indicated that teratozoospermia, like other forms of abnormal semen profiles (aesthenozoospermia, oligozoospermia) is associated with a modest increase in the frequency of sperm chromosome abnormalities. However, FISH studies on some infertile men and mouse strains have suggested that certain types of morphologically abnormal spermatozoa, such as macrocephalic multitailed spermatozoa, are associated with a very significantly increased frequency of aneuploidy. Thus, there may be an association between sperm morphology and aneuploidy in infertile men with specific abnormalities.     

Chromosome analysis by spectral karyotyping of spermatozoa from an oligoasthenozoospermic carrier of a 10; 21 reciprocal translocation

Cytogenetic analysis of germ-line cells prior to intracytoplasmic sperm injection (ICSI) treatment is thought to be necessary for infertile males with an identified chromosomal abnormality. We analyzed the chromosomal karyotype of human spermatozoa from an oligoasthenozoospermic carrier of a reciprocal translocation t(10; 21). Cytogenetic analysis of 39 spermatozoa was performed by spectral karyotyping (SKY) and by ICSI into mouse oocytes. The motile morphologically normal spermatozoa were injected into mouse oocytes. Of these spermatozoa, 38 (97.4%) were activated. Twenty-one (53.8%) of the activated oocytes formed two pronuclei. Metaphase chromosome spreads from 13 spermatozoa were analyzed. Only one spermatozoon was normal and 2 spermatozoa exhibited balanced translocation. Nine and one spermatozoa showed abnormalities related and unrelated to the translocation, respectively. The numbers of normal/balanced spermatozoa were lower than those in previous reports analyzing reciprocal translocations using a previously described technique involving penetrated golden hamster oocytes. After genetic counseling with the carrier and his partner, ICSI treatment was performed. Healthy female and male infants were delivered at 37 weeks gestation via a Caesarean section. The female infant was a carrier of the reciprocal translocation and the male infant was confirmed normal on prenatal diagnosis at 16 weeks gestation. For genetic counseling prior to ICSI treatment, the incidence of unbalanced type spermatozoa after swim-up or Percoll gradient treatment should be investigated and discussed with couples having fertility problems related to oligozoospermia autosomal structural abnormalities.     

Somatic chromosomal abnormalities in infertile men and women

Infertility--the inability to achieve conception or sustain a pregnancy through to live birth--is very common and affects about 15% of couples. While chromosomal or genetic abnormalities associated with azoospermia, severe oligozoospermia or primary ovarian failure were of no importance for reproduction prior to the era of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), advances in assisted reproductive techniques (ART) now enable many infertile couples to have children. These developments have raised the question of the genetic consequences of ICSI: concerns of the potential harm of the invasive procedure and concerns about the genetic risk. The infertile male and female definitely have an increased risk to carry a chromosomal abnormality. Detection of such an abnormality is of fundamental importance for the diagnosis of infertility, the following treatment, the evaluation of the risk for the future child and the appropriate management of the pregnancy to be obtained. Therefore, cytogenetic screening of both partners is mandatory prior to any type of ART. The present review is based on several surveys on male and female infertility and analyzes the types and frequencies of the different reported chromosome abnormalities according to the type of impairment of spermatogenesis and the type of treatment planned or performed. With regard to assisted reproductive techniques (especially ICSI) the main types of chromosomal abnormalities are discussed and their potential risks for ICSI. If available, reported cases of performed ICSI and its outcome are presented. The detection of an abnormal karyotype should lead to comprehensive genetic counselling, which should include all well-known information about the individual type of anomaly, its clinical relevance, its possible inheritance, the genetic risk of unbalanced offspring, and the possibilities of prenatal diagnosis. Only this proceeding allows at-risk couples to make an informed decision regarding whether or not to proceed with ART. These decisions can be made only when both partners have clearly understood the genetic risks and possible consequences when ART is used.     

Chromosomal evaluation in a group of Tunisian patients with non-obstructive azoospermia and severe oligozoospermia attending a Tunisian cytogenetic department

Male infertility is the cause in half of all childless partnerships. Numerous factors contribute to male infertility, including chromosomal aberrations and gene defects. Few data exist regarding the association of these chromosomal aberrations with male infertility in Arab and North African populations. We therefore aimed to evaluate the frequency of chromosomal aberrations in a sample of 476 infertile men with non-obstructive azoospermia (n = 328) or severe oligozoospermia (n = 148) referred for routine cytogenetic analysis to the department of cytogenetics of the Pasteur Institute of Tunis. The overall incidence of chromosomal abnormalities was about 10.9%. Out of the 52 patients with abnormal cytogenetic findings, sex chromosome abnormalities were observed in 42 (80.7%) including Klinefelter syndrome in 37 (71%). Structural chromosome abnormalities involving autosomes (19.2%) and sex chromosomes were detected in 11 infertile men. Abnormal findings were more prevalent in the azoospermia group (14.02%) than in the severe oligozoospermia group (4.05%). The high frequency of chromosomal alterations in our series highlights the need for efficient genetic testing in infertile men, as results may help to determine the prognosis, as well as the choice of an assisted reproduction technique. Moreover, a genetic investigation could minimize the risk of transmitting genetic abnormalities to future generations.     

A comparison of chromosomal aberrations induced by in vivo radiotherapy in human sperm and lymphocytes

Chromosomal aberrations in human sperm and lymphocytes were compared before and after in vivo radiation treatment of 13 cancer patients. The times of analyses after radiotherapy (RT) were 1, 3, 12, 24, 36, 48 and 60 months. The median total radiation dose was 30 Gy and the testicular dose varied from 0.4 to 5.0 Gy. Human sperm chromosome complements were analysed after fusion with golden hamster eggs. There were no abnormalities in sperm or lymphocytes before RT. Following RT there was an increase in the frequency of numerical and structural chromosomal abnormalities in both lymphocytes and sperm. For structural abnormalities there were more rejoined lesions (dicentrics, rings) in lymphocytes and more unrejoined lesions (chromosome breaks, fragments) in sperm. After RT there was a dramatic increase in the frequency of chromosomal abnormalities in lymphocytes: at 1 mo. the frequency was 42%, at 3 mo. 25%, at 12 mo. 14%, at 24 mo. 11%, at 36 mo. 9%, at 48 mo. 7% and at 6 mo. 4%. Since the majority of men were azoospermic after RT, there is little data on sperm chromosome complements before the analyses performed at 24 mo. post-RT. At 24 mo. the frequency of abnormalities was 13%, followed by 21% at 36 mo., 12% at 48 mo. and 22% at 60 mo. Thus it appears that the frequency of lymphocyte chromosomal abnormalities had an initial marked increase after RT followed by a gradual decrease with time whereas the frequency of sperm chromosomal abnormalities was elevated when sperm production recovered and remained elevated from 24 to 60 mo. post-RT. This difference in the effect of time makes it very difficult to compare abnormality rates in lymphocytes and sperm and to use analysis of induced damage in somatic cells as surrogates for germ cells since the ratio between sperm and lymphocytes varied from 1:1 (at 24 mo. post-RT) to 5:1 (at 60 mo. post-RT).     

Management of the infertile couple: an evidence-based protocol

Background

Infertility is defined as inability of a couple to conceive naturally after one year of regular unprotected sexual intercourse. It remains a major clinical and social problem, affecting perhaps one couple in six. Evaluation usually starts after 12 months; however it may be indicated earlier. The most common causes of infertility are: male factor such as sperm abnormalities, female factor such as ovulation dysfunction and tubal pathology, combined male and female factors and unexplained infertility.

Objectives

The aim of this study is to provide the healthcare professionals an evidence-based management protocol for infertile couples away from medical information overload.

Methods

A comprehensive review where the literature was searched for "Management of infertility and/or infertile couples" at library website of University of Bristol (MetaLib) by using a cross-search of different medical databases besides the relevant printed medical journals and periodicals. Guidelines and recommendations were retrieved from the best evidence reviews such as that from the American College of Obstetricians and Gynaecologists (ACOG), American Society for Reproductive Medicine (ASRM), Canadian Fertility and Andrology Society (CFAS), and Royal College of Obstetricians and Gynaecologists (RCOG).

Results

A simple guide for the clinicians to manage the infertile couples.

Conclusions

The study deploys a new strategy to translate the research findings and evidence-base recommendations into a simplified focused guide to be applied on routine daily practice. It is an approach to disseminate the recommended medical care for infertile couple to the practicing clinicians.

     

Cytogenetic survey in couples with recurrent fetal wastage

Summary Cytogenetic studies have been performed in 1068 couples with antecedent fetal wastage, i.e., at least two spontaneous first trimester abortions or one spontaneous first trimester abortion and one late fetal death, particularly with multiple congenital malformations.Three major types: 33 reciprocal translocations (3.09%), 20 Robertsonian translocations (1.87%) and six other chromosomal abnormalities (0.56%) were found, bringing the total number of chromosomal abnormalities to 59 (5.5%) in 1068 couples under investigation.In contrast to couples with reciprocal translocations, a high excess of female over male carriers was found in the group of Robertsonian translocations.In the evaluation of chromosomal polymorphisms, only variants with particularly large paracentromeric constitutive heterochromatin blocks were taken into account, and their low frequency in the present study is therefore not comparable with that in a general population.The impact of further extensive familial investigation on genetic counseling and the follow-up of prenatal diagnosis are discussed.     

The Origin of Abnormalities in Recurrent Aneuploidy/Polyploidy

Recurrent miscarriage due to sporadic chromosomal abnormalities may simply be a consequence of the dramatic increase of trisomic conceptions with increased maternal age. However, it is also possible that some couples are at increased risk of abnormalities as a result of gonadal mosaicism, factors affecting chromosome structure and segregation, increased sperm aneuploidy in the male partner, or accelerated "aging" of the ovaries. We report cytogenetic and molecular findings from 122 spontaneous abortions (SAs) from 54 couples who were ascertained as having two or more documented aneuploid or polyploid SAs. The distribution of abnormalities in this group was similar to those from 307 SAs that involved chromosome abnormalities and were diagnosed at the same center but did not involve documented recurrent aneuploidy/polyploidy. Although recurrence of the same abnormality was observed in eight families, this number was equal to that expected by chance, indicating that gonadal mosaicism is rarely the explanation for recurrence. The origin of the abnormality was determined in 37 SAs from 23 of the couples in the study. A maternal meiotic origin was involved in 30 trisomies and in 1 triploid SA; 3 additional maternal trisomies were of possible somatic origin. A paternal origin was found in the remaining two trisomies and in one triploid SA. In addition, one double trisomy was the consequence of both a maternal and a paternal meiotic error. These results confirm that the etiology of trisomy is predominantly a result of meiotic errors related to increased maternal age, regardless of whether the couple has experienced one or multiple aneuploid SAs. Furthermore, this is true even when a second SA involves the same abnormality. Nonetheless, these data do not exclude some population variability in risk for aneuploidy.     

A comparison of the frequency and type of chromosomal abnormalities in human sperm after different sperm capacitation conditions.

Human sperm karyotypes can be prepared after fusion of human sperm with Golden hamster oocytes. Most laboratories use one of two methods of sperm capacitation: incubation of freshly-ejaculated sperm in Biggers, Whitten, and Whittingham (BWW) medium for 5-7 h at 37 degrees C or sperm storage in (N-tris [hydroxymethyl]methyl-2-aminoethanesulfonic acid; 2-([2-hydroxy-1,1-bis(hydroxymethyl)ethyl]amino)ethanesulfonic acid) (TES)-Tris yolk buffer (TYB) for 1-3 days at 4 degrees C. Since there have been conflicting reports as to whether there is a difference in the frequency of structural chromosomal abnormalities between BWW capacitation and storage in TYB for 2 days, we analyzed a larger number of karyotypes (8974) from 136 donors to determine if there was any difference in the frequency or type of chromosomal abnormalities in sperm treated by fresh BWW capacitation, storage in TYB for 1 day (TYB-1), or storage in TYB for 2 days (TYB-2). There was no difference in the frequency of numerical chromosomal abnormalities or sex ratio in any of the three treatment groups. However, there was a significantly increased frequency of structural chromosomal abnormalities after storage in TYB-1 and TYB-2. There was no difference in the frequency or type of structural chromosomal abnormalities after sperm storage in TYB-1 compared to TYB-2.     

An increased frequency of human sperm chromosomal abnormalities after radiotherapy

13 cancer patients were studied before radiotherapy (RT) and at regular intervals after RT to determine the effect of RT on chromosomal abnormalities in sperm. The men were 19-47 years old and received testicular radiation doses of 0.4-5.0 Gray. Human pronuclear sperm chromosomes were analysed after penetration of zona-pellucida-free hamster eggs. Unfortunately the hamster egg penetration rates were exceedingly low, both before and after RT and this limited the number of sperm chromosome complements which could be analysed. Before RT, the frequency of abnormal sperm chromosome complements was 0% (0/9). After RT, the majority of men were azoospermic for 24 months but complements could be analysed from 4 men. In the first 12 months the frequency of abnormalities was 13% (1/8) and at 24 months it was 13% (7/55). By 36 months after RT, most men had recovered sperm production and the frequency of abnormalities in 8 men was 21% (18/86), which is significantly higher than the rate in control donors (8.5%). For individual men the range was 6-67%, and there was a significant correlation between testicular radiation dose and the frequency of sperm chromosomal abnormalities. The frequencies of both numerical and structural abnormalities were significantly increased after RT. This is the first evidence that radiation may increase the frequency of chromosomal abnormalities in human gametes.     

Characterisation of supernumerary chromosomal markers: a study of 13 cases

Marker chromosomes are defined as 'structurally abnormal chromosomes in which no part can be identified' (ISCN 1995). Supernumerary marker chromosomes (SMC) are 'additional markers' whose origin and composition cannot be determined by conventional cytogenetics. Molecular cytogenetic methods are necessary to identify these additional chromosomal markers. In one third, the SMCs are clinically well-defined in the literature, the remaining two thirds present a major problem for genetic counselling in prenatal diagnosis. At present, different molecular cytogenetic methods are used to determine the origin of SMCs. In this work, we studied 13 SMCs detected by RHG-banding, completed by C-banding and/or NOR-staining. 24-color FISH was used as the primary technique when the chromosomal origin was unknown. Targeted FISH procedures with specific probes (whole chromosome painting, centromeric probe, locus-specific identifier, BAC, etc.) were then performed to confirm and/or specify the chromosomal material present in the SMC. Seven SMCs were found to be associated with phenotypic abnormalities. Five derived from autosomes and two from gonosomes; these are: der(12)t(4;12), dic(15), i(18p), r(19), der(22)t(11;22), r(X), and der(Y). Two markers, r(8) and idic(15), were identified during investigations of infertile couples. Three cases seemed to be phenotypically normal. Four were discovered prenatally: r(2) and r(19) referred for elevated maternal serum markers, der(13/21) referred for advanced maternal age. The fourth SMC, der(14/22), was found during familial investigation following the identification of the same marker in an infertile son. The precise characterisation of the SMCs is of utmost importance for genetic counselling, especially in prenatal diagnosis.