Intracytoplasmic sperm injection could minimize the incidence of prematurely condensed human sperm chromosomes

Importance of sperm gluthatione treatment in ART

PURPOSE

The aim of this study was to investigate whether treatment of sperm from infertile patients would gluthatione could reduce sperm premature chromosome condensation (PCC). To reach the goals of this study, the frequency of sperm PCC formation in sperm of normal and sub-fertile men with/without glutathione treatment were compared and analyzed.

METHODS

Hamster oocytes were retrieved after super ovulation by PMSG and HCG injection. Following treatment with hyaluronidase, zonae was removed by trypsin digestion. Sperm were classified into 3 groups according to morphology, movement and counts, treated with glutathione(10 μg/ml) and then processed by swim up method. After capacitation, zona-free oocytes were incubated with sperm then transferred to fresh media containing colcemid. Cells were fixed and slides prepared using Tarkowskie's standard air drying technique and after staining in 5% Giemsa, oocytes were analyzed at high magnification.

RESULTS

Sperm penetration rate was higher and the rate of intact sperm head and PCC was lower in GSH treated samples compared to non treated groups. Sperm penetration rate was significantly higher in treated astheno sperm samples compared to non-treated ones (66.4% and 50. 97% respectively) (P < 0.001). We observed a significantly higher PCC frequency in infertile patients (P < 0.001). In addition, there was a significantly lower rate of intact sperm head in treated astheno sperm samples (17.49%) compared to non treated ones (26.79%) (P < 0.001). Finally, a significantly lower rate of PCC in treated astheno sperm samples comparing to non treated ones was seen (51.06% and 72.96% respectively) (P < 0. 001).

CONCLUSIONS

Our results show that sperm PCC formation could be one of the major causes of failed fertilization in individuals with sperm abnormalities. Also sperm PCC formation may be involved in the etiology of some cases of idiopathic infertility. Given that the susceptibility of sperm to oxidative stress is significantly greater in idiopathic infertile men, our results show that treatment with glutathione could significantly reduce these stress factors and increase ART outcome.

Molecular and cytogenetic investigation of Y chromosome deletions over three generations facilitated by intracytoplasmic sperm injection

BACKGROUND

The azoospermic factor (AZF) region is critical for normal spermatogenesis since microdeletions and partial deletions have been associated with infertility. We investigate the diagnostic ability of karyotyping in detecting clinically relevant Y chromosome deletions. The clinical significance of heterochromatin deletions, microdeletions and partial AZFc deletions is also evaluated.

METHODS

A patient with a Yq deletion, affected by severe oligoasthenoteratozoospermia, underwent intracytoplasmic sperm injection (ICSI) which resulted in the birth of a healthy baby boy. The patient, his father and his son underwent Y chromosome microdeletion and partial AZFc deletion screening. We also studied the aneuploidy rate in the sperm of the patient by fluorescent in situ hybridization.

RESULTS

AZF microdeletions were absent in the family. However, microdeletion analysis confirmed that the Yq deletion was limited to the heterochromatin. We found a partial AZFc gr/gr deletion in all three family members. We observed an increased rate of sex chromosome aneuploidy in the infertile patient.

CONCLUSIONS

Cytogenetic analysis was misleading in identifying the Yq breakpoint. Infertility observed in the patient was associated with the gr/gr partial deletion. However, because of the incomplete penetrance of gr/gr deletions, the consequence of the vertical transmission of the deletion through ICSI remains unknown.

Can sperm protamine deficiency induce sperm premature chromosomal condensation?

Sperm premature chromatin condensation (PCC) has been considered as the second cause of failed fertilization post-intracytoplasmic sperm injection (post-ICSI). Cytoplasmic factors, including oocyte cytoplasmic immaturity have been suggested to induce PCC sperm. However, recent studies suggest that sperm chromatin anomaly might also lead to PCC sperm. During this study, human sperm from infertile patients with protamine deficiency or with adequate amount of protamine assessed by chromomycin A3 were injected into metaphase II mouse oocyte, treated with colcemid. Chromatin analysis was carried out on the injected oocyte. The results of this study show that contrary to the percentage of intact sperm, percentage of PCC sperm was significantly higher in oocytes injected with protamine deficient sperm (36.43 +/- 4.46) compared to oocytes injected with sperm with an adequate amount of protamine (11.99 +/- 3.54, P < 0.001). A significant correlation was also observed between percentage of PCC sperm and protamine deficiency (r = 0.46, P = 0.004). Therefore, it can be suggested that oocytes injected with protamine deficient sperm have a higher chance of forming PCC sperm and may result in failed fertilization post-ICSI.

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.

Frequency of chromosomal abnormalities in spontaneous abortions derived from intracytoplasmic sperm injection compared with those from in vitro fertilization

No statistical difference was found for the total aneuploidy rate in the spontaneous abortions between intracytoplasmic sperm injection and IVF groups; however, differences in the distribution of chromosomal abnormalities between the two groups were seen.

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.

Relationship between protamine deficiency with fertilization rate and incidence of sperm premature chromosomal condensation post-ICSI

After aneuploidy, sperm premature chromatin condensation (PCC) is the next prevalent cause of fertilization failure. Therefore the aim of this study was to evaluate the effect of sperm protamine deficiency on sperm PCC formation post-ICSI. Chromatin analysis was carried out on failed fertilized oocytes post-ICSI and incidences of sperm PCC were evaluated and the results were compared with the extent of protamine deficiency assessed by chromomycin A3. The results show that incidence of sperm PCC was significantly different in failed fertilized oocytes injected from semen samples with greater or less than 30% CMA3 positivity (P = 0.04). However, except for fertilization rate (P < 0.001), the mean number of MII, MI and germinal vesicles oocytes and percentage normal sperm were not significantly different between the two groups (P > 0.05). A significant correlation was observed between sperm protamine deficiency with fertilization rate. Hence sperm protamine deficiency affects fertilization rate and possibly prones sperm to PCC post-ICSI.