An association between sex chromosomal aneuploidy in sperm and an abortus with 45,X of paternal origin: possible transmission of chromosomal abnormalities through ICSI

BACKGROUND: Although it has been speculated that the increased de-novo chromosomal abnormalities in ICSI pregnancies may be associated with an increase of aneuploidy in sperm from infertile men, little direct evidence exists to support this claim. We studied sperm from an infertile man with an abortus from ICSI to determine if increased sex chromosomal aneuploidy in the sperm could have contributed to the karyotype of the abortus. METHODS: The couple underwent ICSI due to severe oligozoospermia. Spontaneous aborted material was subjected to cytogenetic and molecular tests to ascertain the existence, type and origin of a chromosomal abnormality. Sperm from the man were analysed by multi-coloured fluorescent in-situ hybridization (FISH) with probes specific for chromosomes X, Y and 18. RESULTS: At 8+ weeks after embryo replacement, the patient spontaneously miscarried. Both cytogenetic and comparative genomic hybridization analysis of aborted material showed a 45,X karyotype. Origin of the abnormality was established as a loss of the paternal X chromosome. FISH analysis of sperm revealed 19.6% (1990/10,164) nullisomy for a sex chromosome and 18.6% (1886/10,164) with XY disomy, which is significantly increased when compared to controls with 0.3% (58/20,429) and 0.1% (20/20,429) respectively (P<0.0001). CONCLUSIONS: This study indicates that the paternal origin of the 45,X abortus was likely the result of a high level of nullisomy in the sperm and provides evidence for the transmission of chromosomal abnormality from sperm to the conceptus through ICSI.     

Genetic sonography as the preferred option of prenatal diagnosis in patients with pregnancies following intracytoplasmic sperm injection.

The option of prenatal diagnosis with nuchal translucency measurement at 10-14 weeks of gestation and second trimester targeted ultrasound including fetal echocardiography (genetic sonography) is reported in patients after intracytoplasmic sperm injection (ICSI). From January 1995 to December 1998, 153 consecutive patients, with a mean age of 32.3 years (+/-4.1) and 29. 6% >/= 35 years, who had become pregnant after ICSI, were studied. They attended our unit for first and second trimester sonography. Of these, 67.8% of primigravid and 80.9% of nulliparous women were included. Multiple pregnancy rate was 19.7%; 189 fetuses were screened in total. Due to the introduction of genetic sonography in 1995, the rate of invasive prenatal diagnosis decreased from 74% in 1995, to 48, 36 and 19% in 1996, 1997, and 1998 respectively. Two inherited numerical and structural chromosomal anomalies in clinically healthy children at birth (1.0%) and four major malformations in all liveborn children and late abortions (2.1%) were recorded. The results demonstrate that especially in women of advanced reproductive age with a long history of infertility, detailed genetic sonography may be a reasonable and highly accepted alternative to avoid even the relatively low risks associated with invasive screening procedures.     

苯妥英钠对人精子染色体结构畸变的体外实验

目的：检测苯妥英钠对人精子染色体的诱变效应。方法：应用人精子染色体离体测试系统检测苯妥英钠在3种不同浓度对人精子染色体的损伤作用,并与平阳霉素的阳性对照组和空白对照组比较。结果：苯妥英钠在10μg/ml、20μg/ml、40μg/ml3种浓度的染色体结构畸变精子率和断裂数均较空白对照组高,但仅40μg/ml组的增高,差异有显著性。结论：苯妥英钠对人精细胞可能具有潜在的诱变危害性。     

Mutagenesis-generated mouse models of human infertility with abnormal sperm

BACKGROUND: The aetiology of human male fertility, with impairment of sperm number, motility and morphology (oligoasthenoteratozoospermia), has been difficult to understand, partly for lack of animal models. METHODS: An ethylnitrosourea (ENU) mutagenesis strategy has been successful in producing heritable gene mutations with phenotypes similar to human male infertility, and here, we describe three independent ENU-induced mutations that cause a phenotype of oligoasthenoteratozoospermia in mice. RESULTS: The loci identified by these three mutations are designated swm2, repro2 and repro3. All mutant males were characterized by low sperm concentration, poor sperm morphology and negligible motility, but the infertile males were apparently normal in other respects. Sperm from mutant males failed to fertilize oocytes in vitro. Ultrastructural analyses revealed varied abnormalities apparent in both testicular spermatids and epididymal sperm. Genetic mapping placed the swm2 gene on chromosome 7, the repro2 gene on chromosome 5 and the repro3 gene on chromosome 10. CONCLUSION: The single-gene mutations caused complex and non-specific sperm pathologies, a point with important implications for managing cases of human male infertility. The ultimate identification of the loci for the mutations causing these phenotypes will clarify aetiology of complex syndromes of infertility with sperm abnormalities consistent with oligoasthenoteratozoospermia.     

Should donors have the right to decide who receives their gametes?

A continuing feature of gamete donation is the scarcity of availabledonors. A strategy to improve the meagre supply of gametes wouldbe to adjust the donation procedure to the wishes and desiresof the donors. However, giving donors the right to direct theirgametes to certain groups of recipients goes against the generalrule that donors relinquish all rights and duties. Moreover,allocation by the donor might very well run counter to the rulesof distributional justice. On the other hand, the allocationright can be supported by the principle of autonomy and by thedonor's interest in and contribution to the process. The positionis taken that the donors should have the right to direct theirgametes to categories accepted as relevant by the moral andreligious communities in their society. They should not be giventhe right to add their own categories to the exclusion list.If donors are not allowed to allocate their gift, they shouldat least be informed as to which categories of recipient aretreated by the hospital to enable them to decide whether theywant to donate gametes.     

Andrology: Percutaneous epididymal sperm aspiration for obstructive azoospermia

We report the use of percutaneous epididymal sperm aspirationas a simpler and more acceptable alternative to microscopicepididymal sperm aspiration for patients with obstructive azoospermiain whom bypass surgery is not feasible or has not been successful.Some contamination of the aspirate with blood is inevitable,but with careful sperm preparation techniques this can be reducedsubstantially in the final aliquot used for assisted conception.Spermatozoa with active forward progression may be used forgamete intra-Fallopian transfer treatment, but when this capacityis absent intracytoplasmic sperm injection is recommended. Threepregnancies were obtained in seven couples and a set of twinshas been delivered.     

Risk of cytomegalovirus transmission by cryopreserved semen: a study of 635 semen samples from 231 donors

BACKGROUND: The hypothetical responsibility of sperm donation in cytomegalovirus (CMV) transmission to recipients and precautions to prevent this transmission are widely discussed. The aim of this French CECOS Federation study was to evaluate both the reality and the importance of the CMV risk due to donor sperm and the relevance of measures used to screen it. METHODS: We conducted a prospective multicentric study. CMV was detected by rapid and conventional cultures and by PCR in the frozen sperm of donors who met the normal criteria required of semen donors, irrespective of their CMV serological status. RESULTS: 635 samples from 231 donors (39.4% IgG(+)) were obtained and tested by culture; 551 samples from 197 donors were also tested by PCR. From those samples, 0.78% were culture(+), 1.57% culture(+) and/or PCR(+); 3.3% of seropositive donors and 0.72% of initially seronegative donors were culture(+), but in the latter seroconversion occurred during the quarantine period; of the 197 PCR-tested donors, 3.5% (6.2/1.7) were PCR(+), 3.3% (5.3/1.45) culture(+) and/or PCR(+). PCR(+) samples can be culture(-) and vice versa. The most strongly positive sample corresponded to an initially seronegative donor. CONCLUSION: The best strategy to prevent potential CMV risk is to test donors for CMV IgG and IgM antibody at the outset and after a 6 month period of quarantine and to reject initially IgM seropositive donors or donors who seroconvert during the quarantine period.     

Sex chromosome mosaicism in couples undergoing intracytoplasmic sperm injection

BACKGROUND: Several studies have shown an increased frequency of constitutional chromosome aberrations in male and female partners of couples examined prior to ICSI. We conducted a cohort study to determine whether there was an increase in numerical sex chromosome mosaicism among couples undergoing ICSI compared with fertile couples. METHODS: Cytogenetic investigations were performed in 228 females and 208 males seen for ICSI between January 1997 and March 2001. They were matched to control females and males. RESULTS: Sex chromosome loss or gain was observed in at least one cell from 24.1% of ICSI women in comparison with 22% of controls (not significant). A significant difference between these two groups was found when X chromosome loss in at least two cells was considered, 9.6% for ICSI females versus 4.8% for controls (P = 0.01). No significant difference was observed between male groups concerning loss or gain of the X or Y chromosome. CONCLUSION: Our results support previously published studies indicating that the loss of an X chromosome in a single cell in females undergoing ICSI is probably an artefact. However, they suggest that a woman could have true sex chromosome mosaicism when two 45,X0 cells are found.     

Obstetric outcome of 424 pregnancies after intracytoplasmic sperm injection

An evaluation of the outcome of pregnancies resulting from intracytoplasmicsperm injection for severe male factor infertility was conductedby analysing the data obtained from the patients and/or theirobstetrician/gynaecologist on standardized questionnaires. Thedata from 424 pregnancies between April 1991 and September 1994were analysed. Early pregnancy loss before 16 weeks occurredin 99 cases (23.3%), including 48 clinical abortions (11.3%),47subclinical pregnancies (11.1%) and four ectopic pregnancies(0.9%). Vanishing twins and triplets, which could be regardedas early embryonic wastage, were found in 36 cases (8.5%). Onepregnancy was interrupted at week 15 of gestation because ofanhydramnios, and four pregnancies (0.9%) ended in spontaneouslate abortions before 26 weeks. A total of 320 pregnancies (75.5%)resulted in the birth of at least one child; 222 of these (69.3%)were singletons, 93 were twins (29.1%) and five were triplets(1.6%). The problems of prematurity and low birthweight wereespecially related to the multiplicity of pregnancies. Furthermore,from among the total of 423 babies born, we have observed threecases of stillbirth and five cases of neonatal mortality. Theperinatal mortality rate was therefore 18.9 per 1000 births.The results of this study show that the obstetric outcome ofthese pregnancies was similar to that obtained after conventionalin-vitro fertilization and other assisted reproduction techniques.     

Full-term pregnancies achieved with ICSI despite high levels of sperm chromatin damage

BACKGROUND: Sperm DNA integrity is essential for the accurate transmission of genetic information. The clinical significance of this assessment lies in its association with not only natural conception rates, but also the success of assisted reproduction technology (ART). It has been reported that sperm chromatin structure assay (SCSA) identified thresholds for negative pregnancy outcome after ART when the DNA fragmentation index (DFI), previously known as COMPalphat, was >30%. METHODS: In a prospective clinical study, we examined 34 male infertile patients, the husbands of women undergoing conventional IVF or ICSI. SCSA and ART were carried out on semen aliquots taken from the same ejaculate. Fertilization rate, embryo quality and pregnancy rates were correlated to SCSA parameters, DFI and highly DNA stainable (HDS) cells. RESULTS: No differences were seen in SCSA parameter values between patients initiating pregnancies and not doing so in either ICSI or conventional IVF. Pregnancies and normal delivery were obtained even with high levels of DFI. CONCLUSIONS: There is still controversy over whether analytical techniques currently in use are able to identify the level of damage to spermatozoa. Large-scale studies should be conducted in different clinical settings to determine the effects of sperm DNA damage on the outcome of ART.     

Obstetric and perinatal outcome of pregnancies following intracytoplasmic sperm mjection

The aim of this study was to describe the obstetric and perinataloutcome for births following intracytoplasmic sperm injection(ICSI). Of 210 infants born, 140 were singletons and 70 weretwins. There were no triplets or higher births. The multiplebirth frequency was 20%. Overall, 17% of deliveries were preterm,although for singleton pregnancies the incidence was reducedto 9%. The median birth weight of all live born infants was3168 g and of singletons 3470 g. Of all infants, 17% had a lowbirth weight (<2500 g) and 2% had a very low birth weight(<1500 g). Two major malformations occurred in two singletonchildren and four minor malformations occurred in four children.This was within the range of expected values in Sweden. Karyotypingwas performed in 58 pregnancies. All of them were normal. Theperinatal mortality was 0.5%. In conclusion, in this observationalstudy from Sweden of the first infants born after ICSI in ourprogramme, the incidence of multiple births, preterm births,low birth weight babies and congenital malformations was lowcompared with other series of in-vitro fertilization pregnanciesnot associated with ICSI.     

Recruitment of sperm donors: the Newcastle-upon-Tyne experience 1994-2003

BACKGROUND: The demand for sperm donors has continued despite the introduction of ICSI. This study was undertaken in the light of impending changes in donor anonymity laws to evaluate the recruitment process of sperm donors. METHODS: Retrospective analysis of 1101 potential sperm donors in a tertiary referral centre between January 1994 and August 2003. The main outcome measures were to determine the demographic details, recruitment rate and reasons for rejection of donors. RESULTS: The majority of the applicants were aged <36 years (88.07%), students (54.88%), without a partner (53.47%), unmarried (85.38%) and without proven fecundity (78.67%). Only 3.63% of the applicants were released as donors, 30.79% defaulted, whilst 64.48% were rejected. The most common reason for rejection was suboptimal semen quality (85.07%). Over the years, the numbers of the applicants and released donors have declined significantly. The overall clinical pregnancy rate from donor sperm during this period was 23.52%. CONCLUSIONS: In this successful anonymous sperm donor programme only a small proportion of the applicants are released as donors. The significant decline in released sperm donors coupled with the potential effects of loss of donor anonymity means that new strategies for sperm donor recruitment are urgently required.     

Decline in fertility of mouse sperm with abnormal chromatin during epididymal passage as revealed by ICSI

BACKGROUND: Recent studies showed that ICSI with cauda epididymal or ejaculated sperm of infertile mice or men, respectively, was less effective in fertilization and normal embryo development than ICSI using sperm from the testes. These studies suggested that sperm nuclear quality declined after release from the testis, but the site where this loss of fertility occurs has not been localized. METHODS: We performed ICSI with testicular, caput, and cauda epididymal sperm from infertile Tnp1-/-Tnp2+/- mutant mice, which have a minimal level of transition nuclear proteins and are sterile by natural mating. RESULTS: When the heads of motile sperm from the testis or caput epididymis of Tnp1-/-Tnp2+/- males were injected into enucleated mouse oocytes, sperm chromosomes showed no difference from those of wild-type mice, but the chromosomes from sperm taken from the cauda epididymis of mutant males showed increased abnormalities. Injection of testicular or caput epididymal sperm from Tnp1-/-Tnp2+/- males into intact oocytes resulted in normal embryonic and fetal development and yields of liveborn equivalent to wild-type, but cauda sperm from Tnp1-/-Tnp2-/- mice produced lower implantation rates and yields of liveborn than did those from wild-type mice. CONCLUSIONS: These results demonstrate that in mice with sperm chromatin abnormalities, the decline in fertility of sperm with ICSI occurs after the caput epididymis. The advantage of using caput epididymal sperm for ICSI in certain situations may be considered as an approach to be tested in human assisted reproduction.     

FISH analysis of chromosome X,Y and 18 abnormalities in testicular sperm from azoospermic patients

BACKGROUND: Sperm extracted from testicular biopsies of azoospermic men can successfully be used for ICSI. The concern exists that testicular sperm from azoospermic men suffering from severe testicular failure may have a higher frequency of aneuploidy, which may lead to an increased risk for chromosomally abnormal offspring. METHODS: Testicular sperm from patients showing spermatogenic failure (n = 17) and from patients with normal spermatogenesis (n = 26) were analysed by fluorescence in-situ hybridization (FISH). Numerical chromosomal abnormalities for chromosomes X, Y and 18 were evaluated by FISH in a total of 1697 testicular sperm derived from 43 azoospermic patients. RESULTS: No difference was observed between the frequency of chromosomal abnormalities in testicular sperm from patients with normal spermatogenesis (5.6%) and from patients with spermatogenic failure (8.2%). However, the frequency of aneuploidy for chromosome 18 was higher in the group of azoospermic patients with spermatogenic failure than in the group with normal spermatogenesis (3.2 versus 1.3%). Within the obstructive group, sex chromosome aneuploidy (4.5%) occurred more frequently than chromosome 18 aneuploidy (1.3%; P < 0.001). Among testicular sperm derived from patients with spermatogenic failure, sex chromosomal aneuploidy (5.8%) was similar to that for chromosome 18 (3.2%). CONCLUSIONS: So far, no difference in the total frequency of chromosomal abnormalities has been observed between patients with normal spermatogenesis and patients with severe testicular failure. However, aneuploidy for chromosome 18 was higher in the group with spermatogenic failure.     

Prevalence of chromosomal abnormalities in phenotypically normal and fertile adult males: large-scale survey of over 10,000 sperm donor karyotypes

BACKGROUND: Sperm donors represent an appropriate population for evaluating the frequency of chromosomal abnormalities in phenotypically normal and fertile adult males. METHODS: A large multicentric retrospective study was made within the French CECOS (Centre d'Etude et de Conservation des ufs et du Sperme) for collecting cytogenetic, biological and familial data in sperm donors over a 25-year period. RESULTS: As a whole, 10,202 karyotypes have been recorded. Thirty-eight karyotype aberrations (0.37%) have been diagnosed including 21 balanced chromosomal rearrangements (0.2%). These results are in agreement with those obtained in most large-scale studies performed in unselected newborns. Semen parameters were known for all men carrying an abnormal karyotype and showed normal sperm counts, suggesting that these types of chromosomal aberrations have no or poor consequences on spermatogenesis. Available familial data did not reveal any particular history of malformations, mental retardation or fetal losses. CONCLUSION: This study is the first large-scale cytogenetic study made in normal and fertile males and shows that the frequency of chromosomal aberrations is not influenced by a previous normal fertility or by an uneventful familial history when compared to that found at birth.     

A cytogenetic study of in-vitro matured murine oocytes after ICSI by human sperm

BACKGROUND: The purpose of this study was to investigate the chromosomal complement and developmental potential of in-vitro matured murine oocytes following ICSI by human sperm. METHODS: Heterologous ICSI fertilization between mouse oocytes and human sperm was employed in order to overcome the reduced fertilization rates observed after conventional IVF due to zona hardening during in-vitro maturation, and to assess separately maternal and paternal chromosome complements. Cytogenetic analyses were performed in four types of oocytes: (i) in-vitro matured metaphase II (MII) oocytes; (ii) in-vivo matured MII oocytes; (iii) in-vitro matured oocytes after ICSI; (iv) in-vivo matured oocytes after ICSI. RESULTS: Activation rates after ICSI of in-vitro matured oocytes was lower than that of in-vivo matured oocytes (69.9 versus 97.2%, P < 0.01), and premature chromosomal condensation was only observed in in-vitro matured oocytes. However, there were no significant differences in developmental rates after successful activation between in-vivo and in-vitro matured ICSI oocytes (69.7 versus 76.6%). The incidences of aneuploidy and structural aberrations were similar between the ICSI embryos and non-ICSI (MII) oocytes. Furthermore, the frequency of chromosomal aberrations was not associated with in-vitro or in-vivo maturation. Similar analyses of paternal chromosomes indicated that there were no significant differences in the incidence of chromosomal aberrations between the embryos derived from in-vitro and in-vivo matured oocytes. CONCLUSIONS: These results suggest that in-vitro matured oocytes following ICSI do not lead to an increase in the frequency of aneuploidy and structural aberrations when human sperm are injected into mouse oocytes.     

Adolescents with open-identity sperm donors: reports from 12-17 year olds

BACKGROUND: Donor insemination programs can include 'open-identity' sperm donors, who are willing to release their identities to adult offspring. We report findings from adolescent offspring who have open-identity donors. METHODS: Using mail-back questionnaires, youths from 29 households (41.4% headed by lesbian couples, 37.9% by single women, 20.7% by heterosexual couples) reported their experience growing up knowing how they were conceived and their interest in the donor's identity. RESULTS: Most youths (75.9%) reported always knowing, and were somewhat to very comfortable with their conception origins. All but one felt knowing had a neutral to positive impact on their relationship with their birth mother and, separately, co-parent. The youths' top question about the donor was, 'What's he like?' and >80% felt at least moderately likely to request his identity and pursue contact. Finally, of those who might contact the donor, 82.8% would do so to learn more about him, with many believing it would help them learn more about themselves. No youth reported wanting money and few (6.9%) wanted a father/child relationship. We also discuss differences found among youths from different household types. CONCLUSIONS: The majority of the youths felt comfortable with their origins and planned to obtain their donor's identity, although not necessarily at age 18.     

The relationship between fertility potential measurements on cryobanked semen and fecundity of sperm donors

Sperm penetration assay (SPA) scores obtained from cryobanked semen were correlated with therapeutic insemination (TI) fecundity in a group of established sperm donors, thereby evaluating the efficacy of the SPA in screening donors for sperm banking. While the SPA has been used to separate fertile from infertile males, we altered assay conditions to use frozen semen and to distinguish performance among fertile donors. Three frozen ejaculates from 11 pregnancy-proven donors were analysed. Of 905 TI cycles, 275 recipients achieved 95 pregnancies. There were no significant relationships between fecundity and donor semen, washed sperm parameters, sperm recoveries or recipient age. A significant relationship was revealed between mean SPA scores (range 8.7-66.6 penetrations/ovum) and donor fecundity (range 0.04-0.16, P < 0.03). Sperm concentration was varied in an effort to establish the most sensitive test condition. Using 0.25x10(6) motile spermatozoa/ml, a highly significant relationship was observed (P < 0.002). The four donors with the lowest SPA scores achieved the four lowest fecundities. It is concluded that a modified SPA can be used on frozen donor semen to estimate donor fertility potential. If applied routinely in donor semen banking, poor quality applicants could be excluded, thereby increasing pregnancy rates while decreasing donor screening costs.     

Potential sperm donors', recipients' and their partners' opinions towards the release of identifying information in Western Australia

BACKGROUND: The aim of this study was to examine Western Australian potential sperm donors' and recipients' opinions towards the release of identifying information and their intentions to disclose. METHODS: Forty-five potential sperm donors, 33 recipients and 12 partners completed an anonymous questionnaire regarding their opinions on the release of identifying information, whether a child should be told about the manner of their conception, the level of expected contact of donor with future donor offspring and the importance of anonymity in their decision to donate. RESULTS: Slightly less than one-half (48.9%) of potential donors indicated that they would still donate if their identity was revealed to future offspring. When asked whether they would consider contact with offspring, 80% responded positively, with 42% favouring one-off contact. The majority of recipients (82%) and partners (92%) were planning to inform their offspring about the manner of their conception, with 69% of recipients believing that the offspring should receive identifying information about the donor. Recipients were ambivalent about the level of contact between their offspring and the donor. CONCLUSION: These results suggest that the move to an open-identity donor system in Western Australia will benefit the majority of recipient parents who are intending to disclose; however, it also suggests a 50% decline in the number of potential sperm donors.