Increased incidence of numerical chromosome abnormalities in spermatozoa injected into human oocytes by ICSI

Presentation, medical complications and development of gestational trophoblastic neoplasia of hydatidiform mole after intracytoplasmic sperm injection as compared to hydatidiform mole after spontaneous conception - a retrospective cohort study and literature review

OBJECTIVE

To describe the natural history of hydatidiform mole (HM) after intracytoplasmic sperm injection (ICSI), emphasizing the clinical and oncological outcomes, as compared to patients who had HM after spontaneous conception (SC).

STUDY DESIGN

Retrospective historical cohort study of patients with HM followed at the Rio de Janeiro Federal University, from January 1st 2000-December 31st 2020.

RESULTS

Comparing singleton HM after SC to those following ICSI there were differences in terms of maternal age (24 vs 34 years, p < 0.01), gestational age at diagnosis (10 vs 7 weeks, p < 0.01), preevacuation human chorionic gonadotropin levels (200,000 vs 99,000 IU/L, p < 0.01), occurrence of genital bleeding (60.5 vs 26.9%, p < 0.01) and hyperemesis (23 vs 3.9%, p = 0.02) at presentation, and time to remission (12 vs 5 weeks, p < 0.01), respectively. There were no differences observed in the cases of twin mole, regardless of the form of fertilization that gave rise to HM, except molar histology with greater occurrence of partial hydatidiform mole (10.7 vs 40.0%, p = 0.01) following ICSI. Univariate logistic regression for occurrence of postmolar GTN after ICSI identified no predictor variable for this outcome. However, after adjusting for maternal age and complete hydatidiform mole histology, multivariable logistic regression showed the risk of GTN with HM after ICSI had an adjusted odds ratio of 0.22 (95%CI:0.05-0.93, p = 0.04), suggesting a possible protective effect when compared to HM after SC.

CONCLUSIONS

Singleton HM after ICSI are diagnosed earlier in gestation, present with fewer medical complications, and may be less likely to develop GTN when compared with HM after SC.

Abnormal fertilization in ICSI and its association with abnormal semen parameters: a retrospective observational study on 1855 cases

Intracytoplasmic sperm injection (ICSI) efficiently addresses male factor infertility. However, the occurrence of abnormal fertilization, mainly characterized by abnormal pronuclei (PN) patterns, merits investigation. To investigate abnormal fertilization patterns following ICSI and identify their respective associations with abnormal parameters in semen analysis (SA), a retrospective observational study including 1855 cycles was performed. Male infertility diagnosis relied on the 2010 WHO criteria. The population was divided into groups based on their SA results. The presence of 2PNs and extrusion of the second polar body (PB) indicated normal fertilization. A Kruskal–Wallis test along with a Wilcoxon post hoc evaluation and Bonferroni correction was employed for comparison among the groups. For the pregnancy rate, logistic regression was employed. No correlation was established between the SA abnormalities and the 1PN or 3PN formation rates. The highest and lowest 0PN rates were reported for the oligoasthenoteratozoospermic and normal groups, respectively. The lowest cleavage formation rates were identified in the oligoasthenozoospermic and oligoasthenoteratozoospermic groups. The aforementioned groups along with the oligoteratozoospermic group similarly presented the lowest blastocyst formation rates. For the clinical pregnancy rate, no statistically significant difference was observed. In conclusion, the incidence of two or more abnormal SA parameters – with the common denominator being oligozoospermia – may jeopardize normal fertilization, cleavage, and blastocyst rates. Once the developmental milestone of achieving blastocyst stage status was achieved, only oligoasthenozoospermia and oligoasthenoteratozoospermia were associated with lower rates. Interestingly, following adjustment for the number of blastocysts, no statistically significant differences were observed.

Persistent complete hydatidiform molar pregnancy following assisted reproductive technology in a gestational carrier: Case report

•

While the risk of molar pregnancy is lower when assisted reproduction techniques (ART) are used, it is not eliminated.

•

A gestational carrier developed a complete molar pregnancy, with features indicating persistent trophoblastic disease.

•

Due to the potential for malignant transformation, individuals undergoing ART should be counselled about this risk.

A hydatidiform mole is a rare pathology associated with pregnancy, attributed to abnormal gametogenesis and fertilization. When assisted reproduction techniques (ART) are used, the incidence of molar pregnancy is significantly lower however not eliminated. We report a case of a patient serving as a gestational carrier who developed a complete molar pregnancy, with features indicating persistent trophoblastic disease. This 33-year-old G4T3P0A1L3 woman presented with bleeding at 8 weeks gestational age, after in vitro fertilization and frozen embryo transfer. Ultrasound findings and beta-HCG levels were consistent with molar pregnancy. Pathology specimen from D&C confirmed a complete hydatidiform mole. Despite surgical treatment, beta-HCG remained elevated and multiple pulmonary nodules and enlarged lymph nodes were noted on imaging. Methotrexate was considered but was deemed unnecessary because beta-HCG levels returned to normal over time and nodules resolved. Because molar pregnancy carries a risk of malignant transformation, albeit low, individuals undergoing ART should be counselled.

Hydatidiform molar pregnancy following assisted reproduction

INTRODUCTION

The use of assisted reproduction techniques (ART) is increasing; however, reports of molar pregnancy following ART remain scarce. Currently, the Human Fertility and Embryology Authority (HFEA) collates data on the molar pregnancies that have resulted through the use of ART. Recently, they have indicated that they will no longer collect these data.

AIM

This paper aimed to examine the incidence of molar pregnancy amongst patients undergoing assisted reproduction.

METHODS

We contacted HFEA and placed a request under the Freedom of Information Act (2000) for the number of molar pregnancies that resulted from fresh/frozen embryo transfer since HFEA started collecting data in 1991 to February 2018. We also asked how many patients who had suffered a molar pregnancy went on to have a normal pregnancy and how many had subsequent molar pregnancies, in subsequent treatment cycles.

RESULTS

Between 68 and 76 molar pregnancies occurred within this period using ART (n = 274,655). The incidence of molar pregnancy using fresh intracytoplasmic sperm injection (ICSI) (1/4302) and fresh in vitro fertilisation (IVF) (1/4333) was similar. The risk of recurrence of molar pregnancy following a previous molar was higher following ART compared to spontaneous conceptions.

CONCLUSION

The use of ICSI should be protective against triploidy; however, the retrospective data suggests that molar pregnancy is not eliminated with the use of ART. It is pertinent to continue to record this data, through the gestational trophoblastic disease centres, in order to ensure no further increase in incidence, appropriate follow-up, and transparency in communication.

Unexplained total abnormal fertilization of donor oocytes in ICSI with using spermatozoa from different patients

In this report, we present a case of unexplained total triploidy of donor eggs fertilized by ICSI from four different male partners of different couples. Woman who served as a donor was 27 year old, had her own healthy child, and previously twice served as a donor with normal fertilizations and healthy baby born.

Risk of chromosomal aberration in spermatozoa during intracytoplasmic sperm injection

Intracytoplasmic sperm injection (ICSI) has become critical for the treatment of severe male infertility. The principal feature of ICSI is the direct injection of spermatozoon into an oocyte, which facilitates the production of fertilized embryos regardless of semen characteristics, such as sperm concentration and motility. However, the chromosomal integrity of ICSI zygotes is degraded compared to that of zygotes obtained via in vitro fertilization. This chromosomal damage may occur due to the injection of non-capacitated, acrosome-intact spermatozoa, which never enter the oocytes under natural fertilization. Furthermore, it is possible that the in vitro incubation and pre-treatment of spermatozoa during ICSI results in DNA damage. Chromosomal aberrations in embryos induce early pregnancy losses. However, these issues may be overcome by embryo production using gametes with guaranteed chromosomal integrity. Because conventional chromosome analysis requires fixing cells to obtain the chromosome spreads, embryos cannot be produced using the nucleus that has been analyzed. On the other hand, genome cloning using androgenic or gynogenic embryos provides an additional nucleus for chromosome analysis following embryo production. Thus, this review aims to highlight the hazardous nature of chromosomal aberrations in sperm during ICSI and to introduce a method for the prezygotic examination for chromosomal aberrations.

Comparative study of single-nucleotide polymorphism array and next generation sequencing based strategies on triploid identification in preimplantation genetic diagnosis and screen

Triploidy occurred about 2-3% in human pregnancies and contributed to approximately 15% of chromosomally caused human early miscarriage. It is essential for preimplantation genetic diagnosis and screen to distinct triploidy sensitively. Here, we performed comparative investigations between MALBAC-NGS and MDA-SNP array sensitivity on triploidy detection. Self-correction and reference-correction algorism were used to analyze the NGS data. We identified 5 triploid embryos in 1198 embryos of 218 PGD and PGS cycles using MDA-SNP array, the rate of tripoidy was 4.17‰ in PGS and PGD patients. Our results indicated that the MDA-SNP array was sensitive to digyny and diandry triploidy, MALBAC-NGS combined with self and reference genome correction strategies analyze were not sensitive to detect triploidy. Our study demonstrated that triploidy occurred at 4.17‰ in PGD and PGS, MDA-SNP array could successfully identify triploidy in PGD and PGS and genomic DNA. MALBAC-NGS combined with self and reference genome correction strategies were not sensitive to triploidy.

Cord Blood Karyotyping: A Safe and Non-Invasive Method for Postnatal Testing of Assisted Reproductive Technology Children

Background:

To verify the hypothesis that the incidence of chromosomal abnormalities increases in babies conceived by different assisted reproduction procedures. The availability of the umbilical cord blood encouraged us to study this hypothesis via this method.

Materials and Methods:

This is a descriptive study, umbilical cord blood samples of assisted reproductive technology (ART) children were analyzed with standard cytogenetic techniques (G banding). Karyotyping was possible in 109 cases.

Results:

The number of abnormal cases was four (3.7%), among which, three cases (2.8%) were inherited and only 1 case (0.9%) was a de novo translocation. In total, the incidence of de novo chromosomal abnormalities was in the range observed in all live births in the general population (0.7-1%).

Conclusion:

No significant difference in the incidence of chromosomal abnormality was found between ART and naturally conceived babies. To date, several studies have examined the medical and developmental outcome of ART children and still have not reached a definite conclusion. Genetic counseling is recommended as an integral part of planning of treatment strategies for couples wishing to undergo ART.

Prognostic value of triploid zygotes on intracytoplasmic sperm injection outcomes

PURPOSE

To evaluate the prognostic significance of triploidy incidence on the outcomes of embryos derived from normally fertilized oocytes from the same cohort.

METHODS

This study included 1500 ICSI cycles. Logistic regression models were used to study the influence of abnormal fertilization on the development and clinical outcomes of embryos derived from normally fertilized oocytes from the same cohort

RESULTS

We observed a negative influence of the percentages of triploid zygotes on fertilization (75.2% and 56.8%, P < 0.0001), high-quality embryos (58.9% and 48.2%, P = 0.0001), pregnancy (34.1% and 28.2%, P = 0.0540) and implantation rates (20.0% and 13.3%, P = 0.0012). When the 3PN zygote rate was >25%, the percentages of normal fertilization, high-quality embryos and implantation rates were significantly lower than in the control group.

CONCLUSIONS

We observed an approximately 50% lower risk of pregnancy and a 3.5-fold higher risk of miscarriage in cycles with a 3PN incidence of >25%.

[Postnatal diagnosis and prognosis of 2 cases of triploidy]

Triploidy is one of the most common chromosomal aberrations in spontaneous abortions characterized by a 69-chromosome karyotype. This chromosome abnormality is rare in live-born children. Prevalence is lower than 1/50,000. We report on two premature newborns, male and female, born at 35 and 37 weeks of gestation, who presented with severe intrauterine growth retardation, facial dysmorphy, myelomeningocele, and syndactyly. They died during the first hours of life due to respiratory distress syndrome. Analysis of the karyotype showed a homogeneous triploidy on all mitoses: 69 XXY and 69 XXX. The parental origin of the triploidy can have specific effects in the fetal phenotype and the development of the placenta.

The sex ratio of singleton offspring in assisted-conception pregnancies

OBJECTIVE

To evaluate the effect of intracytoplasmic sperm injection (ICSI) and male factor infertility on the sex ratio in births from assisted reproductive technology.

DESIGN

Historic cohort study.

SETTING

Clinic-based data.

PATIENT(S)

The study population included 15,164 singleton live births in the Society for Assisted Reproductive Technology national database for 2005 from cycles using ejaculated sperm, categorized by the use of insemination or ICSI and the absence or presence of male factor infertility, and cleavage- versus blastocyst-stage embryo transfers (ETs).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The probability of a male infant with and without the use of ICSI and in the presence or absence of male factor infertility.

RESULT(S)

The sex ratio for all U.S. live births in 2005 was 52.5%, versus 48.9% for cleavage-stage and 51.6% for blastocyst-stage embryos. With blastocyst-stage embryos, the sex ratios were 49.6% and 54.9% with and without ICSI and 52.6% and 50.0% with and without male factor infertility, respectively. With cleavage-stage embryos, the sex ratio was not significantly affected by ICSI or male factor infertility, singly or in combination.

CONCLUSION(S)

The use of ICSI, particularly with blastocyst-stage embryos, is associated with a decrease in the sex ratio of male infants.

Use and outcomes of intracytoplasmic sperm injection for non-male factor infertility

OBJECTIVE

To determine whether intracytoplasmic sperm injection (ICSI) is associated with improved outcomes for non-male factor infertility.

DESIGN

We examined the patient characteristics associated with treatment choice-ICSI and conventional in vitro fertilization (IVF)-among patients without a diagnosis of male factor infertility and compared outcomes between the two groups, adjusting for patient characteristics using multivariate regression models.

SETTING

Academic fertility center.

PATIENT(S)

We evaluated 696 consecutive assisted reproductive technology (ART) cycles performed for couples with normal semen analysis at the Stanford Reproductive Endocrinology and Infertility Center between 2002 and 2003. We compared patient characteristics, cycle details, and outcomes for ICSI and IVF.

MAIN OUTCOME MEASURE(S)

Fertilization, pregnancy, and live birth rates.

RESULT(S)

Patient characteristics were similar between the two groups, except the proportion of patients with unexplained infertility (IVF 15.1% vs. ICSI 23.5%), previous fertility (IVF 62.6% vs. ICSI 45.5%), and previous ART cycle (IVF 41.2% vs. ICSI 67.7%). More oocytes were fertilized per cycle for the IVF group (6.6 oocytes versus 5.1 oocytes). Fertilization failure, pregnancy, and live birth rates did not differ between IVF and ICSI. Using logistic regressions, having had previous ART was found to be positively associated with ICSI. Treatment choice of ICSI was not associated with fertilization, pregnancy, or live birth rates.

CONCLUSION(S)

No clear evidence of improved outcomes with ICSI was demonstrated for non-male factor infertility.

Sperm chromatin remodeling after intracytoplasmic sperm injection differs from that of in vitro fertilization

Intracytoplasmic sperm injection (ICSI) is a popular method used in assisted conception, and live offspring have been born from a variety of species, including humans. In ICSI, sperm chromatin is introduced into the oocyte together with the acrosome, a structure that does not enter the oocyte during normal fertilization. We compared sperm chromatin remodeling, the potential of embryos to develop in vitro, and DNA synthesis in mouse embryos obtained from in vitro fertilization (IVF) and ICSI. We also tested whether sperm pretreatment prior to ICSI (i.e., capacitation, acrosome reaction, membrane removal, and reduction of disulfide bonds in protamines) facilitates chromatin remodeling and affects embryo development. Sperm chromatin was examined on air-dried, Giemsa-stained preparations at 30-min intervals for up to 4.5 h postfertilization. In all experimental groups, the oocytes underwent activation and formed pronuclei with similar rates. However, the dynamics of sperm chromatin remodeling in ICSI and IVF embryos varied. In ICSI, chromatin remodeling was more asynchronous than in IVF. Sperm capacitation prior to injection enhanced remodeling asynchrony and resulted in delayed pronuclei formation and DNA synthesis. The removal of the acrosome prior to injection with calcium ionophore A23187 but not with detergent Triton X-100 allowed more synchronous chromatin remodeling, timely DNA synthesis, and good embryo development. Our data have significance for the refinement of the molecular and biologic mechanisms associated with ICSI for current and future applications.

Evaluation of reproductive potential after intracytoplasmic sperm injection of varied human semen tested by antiacrosomal antibodies

OBJECTIVE

To determine whether varied human spermatozoa, as detected with monoclonal antibodies against acrosomal proteins, have an influence on fertilization, transfer, pregnancy, and implantation rates when intracytoplasmic sperm injection is used.

DESIGN

A retrospective study.

SETTING

A private IVF center and academic research laboratory.

PATIENT(S)

One thousand two hundred forty men participating in the intracytoplasmic sperm injection program.

INTERVENTION(S)

Sperm were divided into seven groups: oligozoospermia, oligoasthenozoospermia, and oligoasthenoteratozoospermia and fresh and frozen-thawed epididymal and fresh and frozen-thawed testicular sperm. Fertilization, transfer, pregnancy, and implantation rates were recorded in each category. Sperm were tested with antibodies for detection of the of the sperm acrosome.

MAIN OUTCOME MEASURE(S)

Fertilization, transfer, pregnancy and implantation rates, and percentage of acrosome-reacted cells.

RESULT(S)

The fertilization rate and statistical evaluation showed differences between morphologically normal and pathological sperm and other groups. The freezing-thawing procedure had no influence on the fertilization of testicular sperm, but epididymal frozen-thawed sperm had a higher fertilization rate. Immunofluorescence proved decreasing sperm quality in all groups compared with the control group. This difference is not manifested in other parameters (transfer, pregnancy, implantation rates).

CONCLUSION(S)

The spermatozoa with varied semen characteristics and good quality, also detected with specific antibodies, gave the best fertilization rates. The paternal effect is not proved in other parameters.

Numerical chromosome anomalies detected in paternally derived pronuclei of tripronuclear zygotes after intracytoplasmic sperm injection

OBJECTIVE

To investigate after intracytoplasmic sperm injection (ICSI) the paternal-derived pronuclei of zygotes with three pronuclei (3PN) for numerical-chromosome anomalies by using fluorescence in situ hybridization.

DESIGN

A total of 211 ICSI 3PN zygotes have been analyzed for numerical-chromosome anomalies in paternally derived pronuclei and compared with the group of 82 zygotes originated during IVF. In the ICSI group, 163 zygotes were evaluated for numerical-chromosome anomalies by using DNA probes for chromosomes 18, X, and Y, and 48 zygotes, for chromosomes 21, X, and Y. In the IVF group, 68 zygotes were evaluated for numerical-chromosome anomalies by using probes for chromosomes 18, X, and Y, and 14 zygotes, by using chromosomes 21, X, and Y.

SETTING AND PATIENT(S)

Tripronuclear zygotes were obtained from 74 and 176 patients participating in IVF and ICSI treatment cycles at a university hospital in Switzerland.

INTERVENTION(S)

To evaluate the frequency of numerical-chromosome anomalies in different populations of infertile patients, a total of 211 ICSI zygotes were divided into three groups of zygotes from men with oligozoospermia (n = 124), severe oligozoospermia (n = 53), and azoospermia (n = 34).

MAIN OUTCOME MEASURE(S)

Incidence of sex-chromosome aneuploidy, diploidy, and aneuploidy for chromosomes 18 or 21.

RESULT(S)

Overall incidence of numerical-chromosome anomalies in paternal-derived pronuclei after ICSI (9.5%) was significantly higher than the rate found in paternal-derived pronuclei of IVF zygotes (1.2%). Among ICSI zygotes, sex-chromosome aneuploidy (5.2%) and diploidy (2.8%) were two dominant numerical anomalies in paternal-derived pronuclei. In contrast, aneuploidy for autosomes 18 or 21 was not significantly different when comparing ICSI with IVF zygotes. Regarding different groups of infertile patients, the highest incidence of numerical-chromosome anomalies was found in zygotes originating from men with severe oligozoospermia (13.2%), followed by those originating from men with azoospermia (8.8%) and oligozoospermia (8.1%).

CONCLUSION(S)

Sex-chromosome aneuploidy and diploidy were the most frequent numerical-chromosome anomalies found in paternal pronuclei of ICSI 3PN zygotes. Surprisingly, no statistically significant difference in the incidence of numerical-chromosome anomalies was observed in the three groups of pronuclei derived from men with oligozoospermia, severe oligozoospermia, and azoospermia.

Triploidy formation after intracytoplasmic sperm injection may be a surrogate marker for implantation

OBJECTIVE

Triploidy after intracytoplasmic sperm injection (ICSI) is due mostly to retention of the second polar body. Our interest was to determine the predictors of triploidy and to determine whether the presence of triploidy can serve as a surrogate marker of implantation for the remaining cohort of zygotes.

DESIGN

Cohort study.

SETTING

Academic research center.

PATIENT(S)

Infertile couples undergoing IVF/ICSI.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Triploid zygote (3PN) rate, implantation rate.

RESULT(S)

The 3PN rate is a significant predictor of implantation rate for the remaining cohort of zygotes. The starting and total dose of gonadotropins administered and the total days of stimulation are independent predictors of the 3PN rate.

CONCLUSION(S)

In couples with a normal semen analysis undergoing IVF/ICSI, the 3PN rate may serve as a surrogate marker of oocyte quality and may be altered by adjusting the stimulation protocol.

Frequency and distribution of chromosome abnormalities in human spermatozoa

This study reviews the frequency and distribution of numerical and structural chromosomal abnormalities in spermatozoa from normal men obtained by the human-hamster system and by multicolor-FISH analysis on decondensed sperm nuclei. Results from large sperm karyotyping series analyzed by chromosome banding techniques and results from multicolor FISH in sperm nuclei (of at least 10(4) spermatozoa per donor and per probe) were reviewed in order to establish baseline values of the sperm chromosome abnormalities in normal men. In karyotyping studies, the mean disomy frequency in human sperm is 0.03% for each of the autosomes, and 0.11% for the sex chromosomes, lower than those reported in sperm nuclei by FISH studies using a similar methodology (0.09% and 0.26%, respectively). Both types of studies coincide in that chromosome 21 and sex chromosomes have a greater tendency to suffer segregation errors than the rest of the autosomes. The mean incidence of diploidy, only available from multicolor FISH in sperm nuclei, is 0.19%. Inter-donor differences observed for disomy and diploidy frequencies among FISH studies of decondensed sperm nuclei using a similar methodology could reflect real differences among normal men, but they could also reflect the subjective application of the scoring criteria among laboratories. The mean frequency of structural aberrations in sperm karyotypes is 6.6%, including all chromosome types of abnormalities. Chromosome 9 shows a high susceptibility to be broken and 50% of the breakpoints are located in 9q, between the centromere and the 9qh+ region. Structural chromosome aberrations for chromosomes 1 and 9 have also been analyzed in human sperm nuclei by multicolor FISH. Unfortunately, this assay does not allow to determine the specific type of structural aberrations observed in sperm nuclei. An association between advancing donor age and increased frequency of numerical and structural chromosome abnormalities has been reported in spermatozoa of normal men.

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.

Telomere instability in the male germline

Telomeres play a key role in upholding the integrity of the genome, and telomerase expression in spermatogonial stem cells is responsible for the maintenance of telomere length in the human male germline. We have previously described extensive allelic variation in somatic cell telomere length that is set in the zygote, the ultimate source of which may be the germline. This implies that despite telomerase activity, substantial telomere length variation can be generated and tolerated in the germline; in order to investigate this further, we have examined the nature of telomere length variation in the human male germline. Here, we describe an analysis of both genome-wide telomere length and single molecule analysis of specific chromosome ends in human sperm. We observed individual specific differences in genome-wide telomere length. This variation may result from genetic differences within the components that determine the telomere length setting of each individual. Superimposed on the genome wide telomere length setting was a stochastic component of variation that generates germ-cells containing severely truncated telomeres. If not re-lengthened during early embryogenesis, such telomeres may limit the replicative capacity of cells derived from the zygote and have the potential to create fusagenic chromosomes, unbalanced translocations and terminal micro-deletions. These data may have implications for the genetic determination of ageing, genetic disease and fertility.

Assisted Reproductive Technology and Pregnancy Outcome

OBJECTIVE

To determine whether the use of assisted reproductive technology (ART) is associated with an increase in chromosomal abnormalities, fetal malformations, or adverse pregnancy outcomes.

METHODS

A prospective database from a large multicenter investigation of singleton pregnancies, the First And Second Trimester Evaluation of Risk trial, was examined. Subjects were divided into 3 groups: no ART use, use of ovulation induction (with or without intrauterine insemination), and use of in vitro fertilization (IVF). Multivariate logistic regression analysis was used to assess association between ART and adverse pregnancy outcomes (significance of differences was accepted at P < .05).

RESULTS

A total of 36,062 pregnancies were analyzed: 34,286 (95.1%) were spontaneously conceived, 1,222 (3.4%) used ovulation induction, and 554 (1.5%) used IVF. There was no association between ART and fetal growth restriction, aneuploidy, or fetal anomalies after adjustment for age, race, marital status, years of education, prior preterm delivery, prior fetal anomaly, body mass index, smoking history, and bleeding in the current pregnancy. Ovulation induction was associated with a statistically significant increase in placental abruption, fetal loss after 24 weeks, and gestational diabetes after adjustment. Use of IVF was associated with a statistically significant increase in preeclampsia, gestational hypertension, placental abruption, placenta previa, and risk of cesarean delivery.

CONCLUSION

Patients who undergo IVF are at increased risk for several adverse pregnancy outcomes. Although many of these risks are not seen in patients undergoing ovulation induction, several adverse pregnancy outcomes are still increased in this group. There was no increased incidence of fetal chromosomal or structural abnormalities in the women who used any type of ART compared with the women who conceived spontaneously.

LEVEL OF EVIDENCE

II-2.

Aneuploid analysis of tripronuclear zygotes derived from in vitro fertilization and intracytoplasmic sperm injection in humans

This study demonstrates that the diploid ratio of tripronuclear zygotes after intracytoplasmic sperm injection (ICSI) is significantly higher as compared with that after conventional IVF; the extra pronucleus of tripronuclear zygotes after ICSI are mostly from the second polar body, not from sperm.

A novel method for chromosome analysis of human sperm using enucleated mouse oocytes

BACKGROUND

Mouse oocytes can be used in conjunction with intracytoplasmic sperm injection (ICSI) as a technique to permit chromosomal analysis of human sperm. However, chromosomes derived both from the human sperm and the mouse oocyte appear simultaneously following ICSI. The present study focused on evaluating whether or not previously enucleated mouse oocytes are usable for the analysis of human sperm chromosomes.

METHODS

The metaphase chromosome-spindle complex was removed from a mouse oocyte. Human sperm from a donor with proven fertility were injected into mouse enucleated oocytes or intact oocytes. The presence of pronuclei in the oocytes was confirmed approximately 7-11 h after ICSI, and the oocytes were then fixed so that the nuclei could be observed as chromosome samples at 15-16 h after ICSI.

RESULTS

The formation rate of one pronucleus in enucleated oocytes after ICSI was 93.9% (186/198) while that of two pronuclei in intact oocytes after ICSI was 85.4% (88/103). The appearance rate of metaphase chromosomes of human sperm in the enucleated oocytes, 89.4% (160/179), was significantly higher than that in intact oocytes, 78.7% (74/94) (P = 0.017).

CONCLUSIONS

An efficient ICSI method using enucleated mouse oocytes was established to allow the visualization of the human sperm chromosome complement without the risk of confusion with mouse oocyte chromosomes.

What factors affect intracytoplasmic sperm injection outcomes?

Within the last decade, intracytoplasmic sperm injection (ICSI), a new assisted reproductive technique that allows for the direct injection of spermatozoa into the oocyte, has become available to infertile couples. While most studies indicate that ICSI has success rates similar to those of traditional in vitro fertilization, there are many concerns about the safety of the procedure, including increased risks of chromosomal and developmental abnormalities in children conceived by ICSI. Factors that contribute to these increased risks have not been well elucidated. The purpose of this paper is to review the latest literature concerning 1) the adverse outcomes associated with ICSI; and 2) factors that affect the success rates of ICSI (with emphasis on paternal factors).

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to explain the procedure, intracytoplasmic sperm injection (ICSI), to outline the data surrounding chromosomal and developmental outcomes after ICSI, and to list and explain the potential factors that influence ICSI.

Normal birth after single-embryo transfer in a patient with excessive polypronuclear zygote formation following in vitro fertilization and intracytoplasmic sperm injection

OBJECTIVE

To report an unusual case of idiopathic zygotic polypronuclei.

DESIGN

Case report.

SETTING

Major urban infertility referral center.

PATIENT(S)

A 34-year-old woman with unexplained infertility.

INTERVENTION(S)

The patient underwent two cycles of controlled hyperstimulation and oocyte retrieval followed by in vitro insemination and intracytoplasmic sperm injection (ICSI).

MAIN OUTCOME MEASURE(S)

Pregnancy and delivery of a normal infant following transfer of a single preembryo from an ICSI cycle in which only one zygote showed a normal pronuclear number (2PN) and 12 zygotes appeared polypronucleated (> or =3PN).

RESULT(S)

On the first IVF cycle, 23 oocytes were retrieved and inseminated with 240 x 10(3) motile sperm/mL, after which two zygotes showed a normal pronuclear number and 20 zygotes appeared polyploid with three to seven pronuclei. Transfer of two poor-quality day-3 preembryos following assisted hatching did not achieve pregnancy. On the subsequent ICSI cycle, 33 oocytes were retrieved, and 17 mature oocytes were subjected to ICSI, after which only one zygote showed 2PN and 12 zygotes appeared polyploid with three to eight pronuclei. The normally fertilized zygote developed into a poor-quality, day-3 embryo and was subjected to assisted hatching. Transfer of this preembryo resulted in an uneventful pregnancy and birth of a normal infant.

CONCLUSION(S)

Mechanisms other than polyspermia may result in polypronuclear development in some patients.

[Usefulness and necessity of the andrologist in assisted reproductions units]

In this issue we make a review of our experience in the management of the sterile men: protocols used for the study of men's sterility, causes and specific treatments, surgical recovery of spermatozoa and screening before IVF or IVF-ICSI. We concluded that with an adequate protocol, it's possible to establish the aetiology of men's infertility in a 78.8% of the cases and it's also possible to initiate a specific treatment in almost a 47.8% of men. Results of specific treatment, with a previous selection of patients, could be better than those of assisted reproduction techniques. Best results are obtained in cases of vaso-vasostomy (vasectomy reversal) and obstruction of ejaculatory duct. It's also needed a study of genetics causes and bad prognostic circumstances in those men whose partner is going on with an IVF or IVF-ICSI cycle.

Case report: Partial hydatidiform mole following the transfer of single frozen–thawed embryo subsequent to ICSI

Hydatiform mole is a gestational trophoblastic disease characterized by the dominance of dispermic fertilization. Micromanipulation techniques in assisted reproduction technologies have enabled direct evaluation of the zygotes and the formation of pronuclei in the zygote. Intracytoplasmic sperm injection (ICSI) of oocytes ensures that only a single spermatozoon enters the ooplasma. This study reports a case of partial hydatiform mole following the transfer of day 3 frozen-thawed embryo. ICSI was used as the assisted fertilization method because there was male factor infertility due to severe oligoasthenoteratozoospermia. Possible predisposing factors for partial hydatidiform mole after ICSI are also discussed.

Fertilization abnormalities following human in vitro fertilization and intracytoplasmic sperm injection

Fertilization abnormalities are commonly encountered following in vitro fertilization. The widespread introduction of assisted fertilization methods has rapidly led to a changes in both the incidence and types of these aberrations. Such abnormalities can be identified by careful morphological evaluation at the early zygote stage, of pronuclei as well as of polar body formation, and may be confirmed by cytogenetic assessment. The recognition and understanding of fertilization abnormalities have led to the development of novel techniques aimed at preventing them, as well as recent bold attempts at correction. Removal of one pronucleus may allow some triploid embryos to revert to a normal diploid stage. These new developments should provide insight into the understanding of parthenogenesis, androgenesis, and gynogenesis in the human. Microsc. Res. Tech. 61:358-361, 2003.

Towards a more precise assay of sperm function in egg binding

Historically, the treatment of severe male factor infertility has relied on donor sperm insemination. A decade ago the option of treating severe male factor infertility with partner sperm became a viable alternative. With the introduction of intracytoplasmic sperm injection (ICSI) in conjunction with in vitro fertilization (IVF), only men who produce no sperm are denied the option of fathering their own children. The use of ICSI has been extended to couples with mild male factors. Despite the known genetic risks (both inherent and de novo) of ICSI to offspring, couples with male factors as part of their infertility problem often prefer ICSI to standard IVF, due to apprehension that their sperm might not otherwise succeed in fertilization. This apprehension would be alleviated if an assay for the egg binding capability of human sperm were available. We examine here the possibility that recombinant human zona pellucida 3 (rec hZP3), the primary sperm receptor sulfoglycoprotein of the egg zona pellucida (ZP), be used as a human ZP surrogate for assessing sperm ability to bind to the ZP. Unlike human eggs, which cannot be obtained for this purpose, rec hZP3 can be produced in quantity. An efficient assay can be established by incubating sperm with rec hZP3 coated to a microwell plate. Infertile men with sperm having ability to bind to rec hZP3 can be advised to select standard IVF or intrauterine insemination, which have fewer genetic and medical risks.

Spindle observation in living mammalian oocytes with the polarization microscope and its practical use

The meiotic spindle is crucial for normal chromosome alignment and separation of maternal chromosomes during meiosis. Conventional methods to image spindles rely on fixation and transmission electron microscope or immunofluorescence staining and fluorescence microscope, so they provide limited value to studies of spindle dynamics and human clinical in vitro fertilization. A new orientation-independent polarized light microscope, the LC Polscope, was used to examine the bi-refringent spindles in living mammalian oocytes. It was found that spindles could be imaged with the Polscope in living oocytes in all mammals so far examined, including hamster, mouse, cattle, human, and rat. The first polar body did not accurately predict the spindle location in most metaphase II oocytes. Intracytoplasmic sperm injection (ICSI) could be performed by monitoring spindle position. Studies in humans indicated that, aftr ICSI, higher fertilization and embryonic developmental rates could be achieved in oocytes with than without bi-refringent spindles. Because spindles in most mammalian oocytes are extremely sensitive to slight changes in temperature, maintenance of temperature at 37 degrees C is crucial for normal spindle function. As chromosomes#10; are usually associated with microtubule fibers in the spindles, the position of chromosomes could be indirectly located by imaging spindles. Removing spindles under the Polscope can achieve an enucleation#10; efficiency rate of 100% in mouse oocytes. The Polscope can also be used to examine the spindle dynamics, detect spindle morphology, predict chromosome misalignment, and perform spindle transfer.

Results of preimplantation genetic diagnosis in patients with Klinefelter's syndrome

With the application of preimplantation genetic diagnosis (PGD), a possible genetic contribution of spermatozoa obtained from 47,XXY non-mosaic Klinefelter patients on preimplantation embryos was analysed in eight couples. Interpretable fluorescence in-situ hybridization results were obtained for 28 out of 33 embryos biopsied (84.8%) and 23 blastomeres were analysed for chromosomes 13, 18, 21, X and Y. Nine out of 23 embryos were diagnosed as abnormal (39.1%). Five out of nine contained sex chromosome abnormalities (55.5%). Two were diagnosed as 47,XXY and three were found to have monosomy X. Besides sex chromosomal abnormalities, other abnormalities detected were haploidy, triploidy, monosomy 13, monosomy 18 and trisomy 13. Five blastomeres were analysed for sex chromosomes only and all of them were found to be normal. Overall, the rate of sex chromosome abnormality in biopsied embryos was found to be 17.8% (5/28). Moreover, among 33 embryos biopsied, five of the eight zygotes, which were classified as a poor prognosis group according to pronuclear morphology scoring, showed an impaired growth profile after biopsy and were found to be chromosomally abnormal. Elimination of abnormal embyos and transfer of normal ones resulted in four pregnancies in eight cycles (50%). Two pregnancies, one singleton and one twins resulted in healthy births. Two pregnancies, one singleton and one twins are continuing beyond the second trimester. These results show that there is in fact elevated chromosomal abnormality for both sex chromosomes and autosomes in embryos developed from Klinefelter males. Furthermore together with PGD, embryo scoring according to pronuclear morphology can give additional benefit for selecting chromosomally abnormal embryos. Therefore, PGD should be recommended in cases with Klinefelter's syndrome and this information should be discussed with the couple when genetic counselling is given.

Intracytoplasmic injection of frozen-thawed epididymal spermatozoa in a nonhuman primate model, the cynomolgus monkey (Macaca fascicularis)

Intracytoplasmic sperm injection (ICSI) with frozen-thawed epididymal spermatozoa was performed in the cynomolgus monkey (Macacafascicularis) to produce embryos in vitro. Eleven sexually mature females were hyperstimulated with an GnRH agonist (1.8 mg active triptorelin per 2 kg body weight), followed (2 weeks later) by rFSH (37.5 IU per 2 kg daily) for 12 days, and finally 1000 IU of hCG. Epididymal spermatozoa were collected from a single adult male monkey. The first stimulation cycle resulted in 90 oocytes; 70% of which were metaphase II (MII). Sixty-four percent of these MII oocytes were fertilized. Comparing ovarian response of five monkeys that underwent a second stimulation cycle there was an increase in oocyte quantity (13.2 versus 9.2 oocytes per monkey) but the percentage of MII oocytes remained the same at 58%. Fertilization and cleavage rates were also reduced but there was an increase in the number of embryos available for transfer. Overall, four monkeys became pregnant resulting in the birth of two healthy infants and two abortions. These findings show that ovarian stimulation by GnRH-rFSH did not compromise the developmental competence of the oocytes; effective combination of cryopreservation of epididymal spermatozoa and ICSI is possible in nonhuman primate reproduction, and thus has potential application in the conservation of highly endangered nonhuman primate species, and the cynomolgus monkey is a reliable biomedical research model to study the potential risks and benefits associated with assisted reproductive techniques prior to approval for clinical trials on humans.

Chromosome analysis of epididymal and testicular sperm in azoospermic patients undergoing ICSI

BACKGROUND

Although ICSI provides a way of treating azoospermic men, concern has been raised about the potential risk for transmission of genetic abnormalities to the offspring. We quantified the incidence of chromosomal abnormalities in epididymal and testicular sperm retrieved from azoospermic patients undergoing ICSI.

METHODS

Individual testicular sperm were collected from testicular biopsies with an ICSI pipette, and epididymal sperm were retrieved by microsurgical epididymal sperm aspiration. Samples were processed by fluorescent in-situ hybridization (FISH) for chromosomes 18, 21, X and Y and the results compared with those from normal ejaculated samples.

RESULTS

The overall aneuploidy rate of 11.4% in men with non-obstructive azoospermia was significantly higher (P = 0.0001) than the 1.8% detected in epididymal sperm from men with obstructive azoospermia and also the 1.5% found in ejaculated sperm. No significant difference was found between the epididymal and ejaculated samples. When the chromosomal abnormalities were analysed, gonosomal disomy was the most recurrent abnormality in both obstructive and non-obstructive azoospermic patients, while autosomal disomy was the most frequent in ejaculated sperm.

CONCLUSIONS

Sperm of non-obstructive azoospermic men had a higher incidence of chromosomal abnormalities, of which sex chromosome aneuploidy was the most predominant. Genetic counselling should be offered to all couples considering infertility treatment by ICSI with testicular sperm.

Induction of the acrosome reaction and zona-free hamster oocyte penetration by a bull with complete teratospermia versus a half brother with normal sperm

A fertile bull producing normal sperm and a sterile half brother exhibiting 100% teratospermia were available to study an induced sperm acrosome reaction and oocyte penetration. Pedigree analysis indicated that this condition was inherited. Experiments were undertaken to study the induction of the acrosome reaction using dilaurylphosphatidylcholine (PC12) liposomes, because this procedure was previously established to be highly correlated with bull fertility. The sperm from each bull were incubated with several PC12 concentrations for varying time periods. The initial percentages of sperm from the sterile bull with intact, partially intact, and lost acrosomes were 67%, 18%, and 14%, respectively, vs 82%, 13%, and 5% for the fertile bull (P < .05). After incubation for 15 minutes with 50 microM PC12 liposomes the corresponding values were, respectively, 51%, 26%, and 19%; and 60%, 28%, and 12%. Thus, the differences after induction of the acrosome reaction, although significant (P < .05), were small. The number of sperm adhered to each oocyte averaged 22 and 10, respectively, for the fertile and sterile bulls, whereas 74% of the fertile bull sperm and only 11% of the sterile bull sperm penetrated oocytes. Mixing the sperm-oocyte complex during incubation and increasing the sperm concentration during incubation to compensate for differences in sperm motility did not markedly affect oocyte penetration by teratogenic sperm, which is consistent with this bull being sterile. In other studies, microinjection of this type of sperm was demonstrated to induce fertilization, so the consequences of using sperm with hereditary defects in assisted reproductive programs to overcome human male sterility may be a concern.

The transmission of mitochondrial DNA following assisted reproductive techniques

Mitochondria, among other functions, generate energy in the form of ATP. The chondrial genome, located within each mitochondrion, encodes some of the polypeptides associated with the electron transfer chain (ETC) and ATP production. Transcription and replication of mitochondrial DNA (mtDNA) is dependent upon the import of transcription and replication factors encoded by the nucleus. Certain point mutations and large-scale deletions to mtDNA can be either severely debilitating or lethal. The transmission and inheritance of mtDNA [not readable: see to offspring is strictly regulated and specific to each species. In many mammalian systems, paternal mtDNA is eliminated very early during embryonic development. However, it is possible that the paternal molecule could be extruded to those cells destined to become trophoblasts and may act as a regulator of embryonic cell fate. Furthermore, the increasing use of more sophisticated assisted reproductive techniques has led to the incorporation of extraneous mtDNA in both the reconstructed oocyte and embryo with transmission to the offspring at varying degrees.

Cytogenetic analysis of human zygotes displaying three pronuclei and one polar body after intracytoplasmic sperm injection

BACKGROUND

Digynic zygotes with three pronuclei and one polar body obtained after intracytoplasmic sperm injection (ICSI) were studied cytogenetically to elucidate the frequency and origin of chromosomal abnormalities at the earliest stage of conception.

METHODS

Uncleaved, single-cell zygotes were incubated with podophyllotoxin and vinblastine and fixed by a gradual fixation air drying method. The chromosomes were stained with Giemsa.

RESULTS

Twenty-two (50%) out of 44 informative zygotes revealed cytogenetic alterations, including aneuploidy (six cells, 13.6%), structural aberrations (10 cells, 22.7%) and combinations of numerical and structural abnormalities (two cells, 4.5%). In one case (2.3%), double aneuploidy or an effect of chromosomal translocation could not be distinguished and one zygote (2.3%) turned out tetraploid due to injection of a diploid spermatozoon. Two zygotes (4.5%) showed an irregular chromatid segregation between the two maternal complements. In completely analysable cells, the sex chromosome ratio XXX:XXY was 17:15.

CONCLUSIONS

Digynic ICSI zygotes carry a high rate of cytogenetic abnormalities that obviously have been transmitted by the participating oocytes and spermatozoa. We also confirmed the previously reported, possibly ICSI-induced irregular oocyte chromatid segregation. The results suggest that aneuploidy in the oocytes must have been caused by predivision instead of non-disjunction.

Molecular insights into the causes of male infertility

Infertility is a reproductive health problem that affects many couples in the human population. About 13-18% of couple suffers from it and approximately one-half of all cases can be traced to either partner. Regardless of whether it is primary or secondary infertility, affected couples suffer from enormous emotional and psychological trauma and it can constitute a major life crisis in the social context. Many cases of idiopathic infertility have a genetic or molecular basis. The knowledge of the molecular genetics of male infertility is developing rapidly, new "spermatogenic genes" are being discovered and molecular diagnostic approaches (DNA chips) established. This will immensely help diagnostic and therapeutic approaches to alleviate human infertility. The present review provides an overview of the causes of human infertility, particularly the molecular basis of male infertility and its implications for clinical practice.