A comparison of sperm aneuploidy rates between infertile men with normal and abnormal karyotypes.

BACKGROUND: Abnormal semen parameters in chromosomally normal men are an indicator of an increased risk of sperm aneuploidy. Male carriers of chromosomal rearrangements may also display an increase in sperm aneuploidy for chromosomes not involved in the rearrangement, known as an interchromosomal effect (ICE), and this may be related to the impaired semen parameters of these men. METHODS: Aneuploidy was examined in ejaculate sperm from 27 men: 8 carriers of chromosomal rearrangements with severe oligoasthenoteratozoospermia (OAT) or severe teratozoospermia; 10 chromosomally normal men with similarly abnormal semen parameters; and 9 proven fertile men with normal semen parameters. Fluorescence in situ hybridization was used to examine aneuploidy for chromosomes 13, 18, 21, X and Y. RESULTS: We observed evidence of an ICE in three of the eight carriers of chromosomal rearrangements. However, men who were chromosomally normal but had severe OAT more frequently displayed increased disomy rates. Although autosomal disomy rates were only modestly increased in some of these men, increased XY disomy ranged from slight to extreme (up to a 100-fold increase). CONCLUSIONS: Despite their similar semen parameters, infertile men with normal karyotypes displayed more frequent increases in sperm aneuploidy, particularly involving the sex chromosomes, than infertile men who were carriers of chromosomal rearrangements. The difference in the magnitude and type of sperm aneuploidy between the two infertile groups is likely related to the different causes of infertility.

Impact of assisted hatching on the outcome of intracytoplasmic sperm injection: a prospective, randomized clinical trial and pregnancy follow-up.

OBJECTIVE: To evaluate the overall effect of assisted hatching (AH) on the implantation, pregnancy, and live birth rates in women undergoing intracytoplasmic sperm injection (ICSI) cycles; and to determine the effect of AH on the cytogenetic outcome (chromosomal constitution) of pregnancy. DESIGN: Prospective, randomized study. SETTING: Academic research environment. PATIENT(S): A total of 172 couples were enrolled in the study. INTERVENTION(S): Assisted hatching was carried out on day-3 ICSI embryos. MAIN OUTCOME MEASURE(S): Implantation, clinical pregnancy, and live birth rates; cytogenetic analysis of abortuses and umbilical cord blood samples from newborns. RESULT(S): Biochemical, clinical, and ongoing pregnancy rates were not significantly different between the AH and control groups. The implantation rate was higher in the AH group than in the control group (16% vs. 8%), especially in women aged > or =35 years. Postnatal umbilical cord blood samples were collected and cytogenetically analyzed from 39 live births (20 from the AH group, 19 from the control group). Two abnormal karyotypes were found (one AH, one control). There were seven spontaneous losses during the study interval. Six of the abortuses underwent cytogenetic study (five AH, one control), and four were found to have an abnormal karyotype (three AH, one control). CONCLUSION: We found that AH improves implantation rates of ICSI cycles and seems to be most effective in women aged > or =35 years. A larger sample size is needed to determine whether AH improves the take-home-baby rate. Assisted hatching did not affect the rate of chromosomal abnormalities in live births in this study.

Investigation of confined placental mosaicism (CPM) at multiple sites in post-delivery placentas derived through intracytoplasmic sperm injection (ICSI).

Although earlier studies on pregnancies derived through intracytoplasmic sperm injection (ICSI) reported increased non-mosaic aneuploidy among ICSI children, undetected mosaicism, such as confined placental mosaicism (CPM) has not been evaluated. We investigated the incidence of CPM in post-delivery placentas derived from ICSI, evaluated whether CPM was increased and whether it was a contributing factor to negative pregnancy outcome. [Fifty-one post-delivery placentas were collected from patients who underwent ICSI with a normal or negative pregnancy outcome]. Trophoblast and chorionic stroma from three sites were analyzed by comparative genomic hybridization (CGH) and flow cytometry. Detected abnormalities were confirmed by fluorescence in situ hybridization (FISH). The incidence of CPM in the ICSI population was compared to the general population from published data. We detected three cases of CPM in our study. One abnormality was found by CGH analysis; partial trisomy 7q and a partial monosomy Xp limited to the trophoblast at two sites. The abnormality was associated with a child affected by spina bifida. Two cases of mosaic tetraploidy were observed by flow cytometry in pregnancies with a normal outcome. All three abnormalities were confirmed by FISH analysis. The incidence of CPM in the ICSI study population was 5.88% (3/51), which was not statistically different from published reports in the general population (5.88% (42/714), Chi square, P > 0.05). The post-ICSI population was not at risk for CPM in this study.

ICSI and the transmission of X-autosomal translocation: a three-generation evaluation of X;20 translocation: case report.

Published reports show that male carriers of an X-autosome translocation, which is either inherited from their mother or is de novo, are generally sterile, regardless of the position of the breakpoint in the X chromosome. We report a three-generation propagation of such a translocation in a family with a case of male factor infertility. Due to the condition of severe oligozoospermia, the proband and his wife underwent ICSI, which resulted in the birth of a normal healthy female. Cytogenetic (chromosome) analyses and X-chromosome inactivation (XCI) assays were done on the family. The cytogenetic analysis of the proband, a man with severe oligozoospermia, revealed an X-autosomal translocation, 46,Y,t(X;20)(q10;q10), which was inherited from his mother. His brother had the same translocation. Amniocentesis and post-natal umbilical cord analyses revealed that the female infant carried the same translocation as her father. XCI studies showed highly skewed inactivation of the normal X chromosome in the female infant, her paternal grandmother, and her mother who had a normal karyotype. In contrast to the data from the literature, our study suggests that men with a certain type of X-autosomal translocation could conceive children through ICSI in conditions in which a few spermatogonia are able to complete meiosis II. The literature involving X-autosomal translocation in males is also reviewed and the importance of the study of X-chromosomal inactivation in female infants discussed.

In-vivo ovarian androgen responses to recombinant FSH with and without recombinant LH in polycystic ovarian syndrome.

BACKGROUND: Effects of exogenous LH on ovarian androgen secretion during ovulation induction have not been clearly characterized in polycystic ovarian syndrome (PCOS). The purpose of this study was to compare androgen secretion in PCOS women during ovarian stimulation with either recombinant FSH (rFSH) alone or combined with recombinant LH (rLH). METHODS: Clomiphene-resistant women with PCOS were allocated, in a factorial study design, to receive either daily injections of rFSH (n = 24) or rFSH + rLH (n = 24) in a 1:1 ratio starting: (i) on day 2-3 of progestogen-induced menses (n = 8); (ii) after 6 weeks of GnRH agonist treatment (nafarelin, 400 micro g twice daily; n = 8); or (iii) after nafarelin treatment as in (ii) plus dexamethasone (n = 8). The effects of rFSH with rFSH + rLH under these three hormone conditions on serum LH, 17alpha-hydroxyprogesterone (17-OHP), androstenedione (DeltaDelta(4)) and testosterone were contrasted by analysis of variance with specific treatment days as a repeated measures factor. RESULTS: Pre-study hormone levels were similar for all groupings. Nafarelin significantly suppressed LH levels, which remained at the lower limit of assay sensitivity (0.5 IU/l) during stimulation with rFSH but increased significantly to >1 but <2 IU/l when rLH was added. As expected, 17-OHP, DeltaDelta(4) and testosterone levels fell following nafarelin treatment. Dexamethasone further suppressed 17-OHP, DeltaDelta(4) and testosterone levels and unmasked a small but significant rise in these ovarian steroids 24 h following the first dose of rFSH + rLH, a rise that was absent with rFSH alone. Secretion of these steroids then appeared to 'catch-up' after 5 days of rFSH stimulation. CONCLUSIONS: Despite profound LH, 17-OHP, DeltaDelta(4) and testosterone suppression, comparable E(2) response, follicle development and successful pregnancies in PCOS subjects receiving rFSH alone to those receiving rFSH + rLH would argue that circulating LH at levels as low as 0.5 IU/l are sufficient to sustain adequate follicle development and function when FSH is present in abundance. Whether the observed dichotomy between rFSH and rFSH + rLH treatment in temporal secretion patterns reflects a greater reliance on evolving paracrine mechanisms as the follicles mature under profound LH suppression remains to be explored but may influence the optimal LH threshold for ovulation induction in PCOS.

Intracellular calcium mobilization in response to the activation of human wild-type and chimeric gonadotropin receptors.

It is well established that LH action is mediated primarily by adenylate cyclase/cAMP. However, the role of inositol phosphate/calcium in LH signaling is less well established. We examined the effects of gonadotropins in primary culture human granulosa-lutein cells and in HEK293 cells transiently transfected with human wild-type or chimeric gonadotropin receptors. The intracellular free calcium concentration was measured using fura-2 microspectrofluorometric techniques. Human (h) LH (2-4 microg/ml) and CG (10 IU/ml) consistently evoked oscillatory calcium signals in HEK293 cells transfected with hLH receptor, whereas hFSH (2-4 microg/ml) failed to elicit any response. Conversely, both hLH and hFSH failed to elicit a calcium response from HEK293 cells transfected with hFSHR, indicating the specificity of the response to the LH receptor. Pretreatment of transfected HEK293 cells with pertussis toxin (100 ng/ml) attenuated all gonadotropin-evoked calcium mobilization. Studies with chimeric LH receptor showed that the sequence of the long extracellular portion of the receptor was not critical for stimulation of PLC activity, but maintained agonist binding specificity. The C-terminal sequence of the receptor was clearly important for the generation of the basal calcium oscillations, but the precise extent of the critical sequence has yet to be identified. Although various subdivisions of this region were capable of stimulating calcium transients, an intact carboxyl-terminal third of the receptor was required for normal and sustained intracellular calcium signaling. Our study unequivocally shows that the hLH receptor is coupled to the inositol phosphate/calcium signaling pathway via a pertussis toxin-sensitive G protein-coupled receptor.