Intracytoplasmic sperm injection: a review of risks and complications

The bibliometric analysis of studies on intracytoplasmic sperm injection from 2002 to 2021

BACKGROUND

Infertility is estimated to occur in 1 out of every 4-7 couples. Intracytoplasmic sperm injection (ICSI), a type of assisted reproduction introduced in 1992, has been used across the world for almost all indications of infertility, yielding high pregnancy rates. There is a growing concern worldwide about ICSI since semen quality has declined in recent years, accompanied with the potential risks of this technology. This study aims to analyze the current status and hotspots of ICSI via a bibliometric analysis.

METHODS

We retrieved publications on ICSI from the Web of Science Core Collection database from 2002 to 2021. CiteSpace was used to summarize knowledge mapping of subject categories, keywords, and co-citation relationships with the strongest citation bursts. VOSviewer was used to explore co-citation and co-occurrence relationships for countries, organizations, references, authors, and keywords.

RESULTS

A total of 8271 publications were analyzed between 2002 and 2021. The major findings are as follows: the USA, China, Italy, Japan, and Belgium are the top five prolific countries. The Free University of Brussels, University of Copenhagen, University of Valencia, Ghent University, and the University of California San Francisco are the top five contributing organizations. Fertility and Sterility and Human Reproduction are the most productive and cited journals. The hotspot topics are risks of ICSI, oocyte preservation, live birth rate, infertile men, and embryo quality in the past two decades.

CONCLUSION

This study presents a research overview of ICSI from different perspectives. These findings will contribute to a better understanding of the current status of ICSI research and provide hotspots and trends for future studies.

Risk of birth defects in children conceived with assisted reproductive technology: A meta-analysis

BACKGROUND

Although assisted reproductive technology (ART) is extensively used in couples with fertility problems, the risk of birth defects among infants conceived with ART is still a concern. Therefore, to more accurately assess the risk of birth defects after ART treatment, we performed a meta-analysis of all available cohort studies relating to birth defects among infants conceived with ART.

METHODS

We used an established strategy to search the databases of PUBMED, EMBASE, COCHRANE, WEB OF SCIENCE, CNKI, CBM and VIP for studies published between 2008 and 2020. Subgroup analyses and sensitivity analyses were used to examine sources of heterogeneity. Pooled adjusted odds ratios (ORs) were calculated using a fixed effects model. RevMan5.3 was used to draw a forest plot, and Stata14.0 was used to test for publication bias.

RESULTS

We included 14 cohort studies from different countries. The infants conceived with ART had a 1.22-fold higher likelihood of birth defects than children born after natural pregnancy(OR = 1.22, 95% CI [1.17, 1.28], P < .05). The prevalence of birth defects after ART treatment was higher in singleton births than in multiple births. In a meta-analysis of data from 6 studies, we found associations between ART and birth defects related to specifics organs: cardiovascular defects, OR = 1.51, 95% CI [1.34-1.69], P < .05; musculoskeletal defects, OR = 1.09, 95% CI [1.03-1.15], P < .05; urogenital defects, OR = 1.24, 95% CI [1.11-1.38], P < .05; central nervous system defects, OR = 1.33, 95% CI [1.14-1.55], P < .05; and orofacial defects, OR = 1.45, 95% CI [1.15-1.83], P < .05.

CONCLUSIONS

ART treatment does present an increased risk of birth defects. The prevalence of birth defects after ART treatment is lower in multiple births than in singleton births. Further research is required to examine the risks for birth defects after ART treatment.

Intracytoplasmic sperm injection vs. conventional in vitro fertilization in patients with non-male factor infertility

OBJECTIVE

To compare the cumulative live birth rates (CLBRs) and cost effectiveness of intracytoplasmic sperm injection (ICSI) and conventional in vitro fertilization (cIVF) for non-male factor infertility.

DESIGN

A retrospective cohort study.

SETTING

Society for Assisted Reproductive Technology clinics.

PATIENT(S)

A total of 46,967 patients with non-male factor infertility with the first autologous oocyte retrieval cycle between January 2014 and December 2015.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcomes were CLBR, defined as up to 1 live birth from an autologous retrieval cycle between 2014 and 2015, and linked fresh and frozen embryo transfers through 2016. The secondary outcomes included miscarriage rate, 2 pronuclei per oocyte retrieved, and the total number of transferred and frozen embryos. Analyses were performed on subsamples with and without preimplantation genetic testing for aneuploidy (PGT-A). A cost analysis was performed to determine the costs accrued by ICSI.

RESULT(S)

Among cycles without PGT-A in patients with non-male factor infertility, the CLBR was 60.9% for ICSI cycles vs. 64.3% for cIVF cycles, a difference that was not significantly different after adjustment for covariates (adjusted risk ratio, 0.99; 95% confidence interval, 0.99-1.00). With PGT-A, no difference in CLBR was found between ICSI and cIVF cases after adjustment (64.7% vs. 69.0%, respectively; adjusted risk ratio, 0.97; 95% confidence interval, 0.93-1.01). The patients were charged an estimated additional amount of $37,476,000 for ICSI without genetic testing and an additional amount of $7,213,500 for ICSI with PGT-A over 2 years by Society for Assisted Reproductive Technology clinics.

CONCLUSION(S)

In patients with non-male factor infertility, ICSI did not improve CLBR. Given the additional cost and the lack of CLBR benefit, our data show that the routine use of ICSI in patients with non-male factor infertility is not warranted.

Advancing parental age and autism: multifactorial pathways

Converging evidence from epidemiological, genetic, and animal studies supports the hypothesis that advancing parental age, both of the father and mother, increases the risk of autism spectrum disorders (ASD) in offspring. Paternal age has received considerable attention, with whole-genome sequencing studies linking older fathers to higher rates of de novo mutations and increased risk of ASD. The current evidence suggests that the increased risk of ASD in the offspring of older mothers may be related to mechanisms different from those operating in older fathers. Causal pathways probably involve the interaction of multiple risk factors. Although the etiology of ASD is still poorly understood, studies of parental age provide clues into the genetic and environ-mental mechanisms that mediate the risk of ASD.

The paediatric consequences of Assisted Reproductive Technologies, with special emphasis on multiple pregnancies

Paediatricians will encounter many babies and children who are the result of assisted reproductive technologies. Although in most cases, there are no adverse health consequences, assisted reproductive technologies (ART) are associated with some risks that are reviewed in this article.

CONCLUSION

ART has had a major impact on multiple gestation and the incidence of prematurity in many countries. Among singletons, there are also increases in prematurity, small for gestational age, congenital anomalies and perinatal mortality.

Should few retrieved oocytes be as an indication for intracytoplasmic sperm injection?

OBJECTIVE

To reevaluate whether relatively few oocytes obtained in one cycle are an indication for intracytoplasmic sperm injection (ICSI).

METHODS

A total of 406 cycles with three or fewer retrieved oocytes performed in 396 non-male infertile couples were retrospectively reviewed. Cycles were classified into three groups by different fertilization techniques: the in vitro fertilization (IVF) group, insemination with conventional IVF; the ICSI group, insemination with ICSI though semen parameters were normal; and the rescue ICSI group, re-insemination with ICSI after conventional IVF failure.

RESULTS

The ICSI group resulted in higher normal fertilization compared with the conventional IVF group. Correspondingly, the cycle cancellation rate was decreased in the ICSI group, though it was not statistically significant. The clinical pregnancy rate and implantation rate were lower in the ICSI group compared with the conventional IVF group. Rescue ICSI was a method to avert total fertilization failure in conventional IVF, increasing fertilization and ensuring embryo availability for transfer, but the normal fertilization was the lowest due to delayed insemination and the chance of pregnancy was very little.

CONCLUSIONS

Obtaining only few oocytes in one cycle is not considered as an indication for ICSI when the sperm sample is apparently normal. Rescue ICSI is either not recommended if conventional insemination fails. Such patients should not be subjected to the unnecessary costs and potential risks of ICSI.

Methodology matters: IVF versus ICSI and embryonic gene expression

The use of assisted reproduction treatment, especially intracytoplasmic sperm injection (ICSI), is now linked to a range of adverse consequences, the aetiology of which remains largely undefined. Our objective of this study was to determine differences in gene expression of blastocysts generated by ICSI as well as ICSI with artificial oocyte activation (ICSI-A) versus the less manipulative IVF, providing fundamental genetic information that can be used to aid in the diagnosis or treatment of those adversely affected by assisted reproduction treatment, as well as stimulate research to further refine these techniques. Murine blastocysts were generated by ICSI, ICSI-A and IVF, and processed for a microarray-based analysis of gene expression. Ten blastocysts were pooled for each procedure and three independent replicates generated. The data were then processed to determine differential gene expression and to identify biological pathways affected by the procedures. In blastocysts derived by ICSI versus IVF, the expression of 197 genes differed (P < 0.01). In blastocysts derived by ICSI-A versus IVF and ICSI-A versus ICSI, the expression of 132 and 65 genes differed respectively (P < 0.01). Procedural-induced changes in genes regulating specific biological pathways revealed some consistency to known adverse consequences. Detailed investigation of procedure-specific dysfunction is therefore warranted.

Comparison of ICSI and conventional IVF in patients with increased oocyte immaturity

Using sibling oocytes, the objective of this study was to compare the intracytoplasmic sperm injection (ICSI) fertilization rates to those achieved with conventional IVF in patients with high rates of oocyte immaturity. This study was observational in nature, and included 91 patients who were treated using split insemination techniques. The fertilization rates for the ICSI group and the IVF group were 41.1 +/- 15.0% and 53.2 +/- 19.8%, respectively (P &lt: 0.0001). There was no significant difference in day-3 embryo quality between the two groups. There was a significantly higher number of embryos frozen in the IVF group than in the ICSI group: 357 (84.8%) and 297 (76.7%), respectively (P = 0.037). Furthermore, the number of embryos either transferred or frozen was significantly higher in the IVF group than the ICSI group: 459 of 1173 (39.1%) and 385 of 1268 (30.4%), respectively (P < 0.0001). These data indicate that conventional IVF results in a higher fertilization rate than ICSI. Furthermore, IVF provided more embryos available for transfer or cryopreservation when compared with ICSI, thereby optimizing the patient's cycle.

Comparing intracytoplasmic sperm injection and in vitro fertilization in patients with single oocyte retrieval

OBJECTIVE

To compare the efficacy of intracytoplasmic sperm injection (ICSI) and conventional IVF in patients with favorable and poor sperm parameters in which only a single oocyte was available for insemination.

DESIGN

Retrospective analysis.

SETTING

University-affiliated IVF center.

PATIENT(S)

A total of 311 patients (425 cycles) who underwent either stimulated or spontaneous IVF cycles that resulted in single oocyte retrieval.

INTERVENTION(S)

The ICSI was indicated when fertilization failure was anticipated because of sperm quality or other confounding female factors.

MAIN OUTCOME MEASURE(S)

Fertilization rates and pregnancy rates (PRs) were analyzed according to the woman's age (< or =39 or >39 years), sperm quality, and mode of insemination.

RESULT(S)

In patients <39 years old with favorable semen quality, ICSI and standard insemination produced similar fertilization rates (67.1% vs. 75.0%) and PRs (0.0 vs. 8.2%). Conversely, in cases with apparent lower semen quality, ICSI gave a significantly higher fertilization rate (85.4% vs. 44.2%) but no significant difference in PRs (14.6% vs. 4.7%). In patients >39 years old and with favorable semen quality, ICSI and standard insemination produced similar fertilization rates (82.4% vs. 68.4%) and PRs (0.0 vs. 1.1%). The ICSI for lower semen quality, however, produced both higher fertilization rates (84.0% vs. 52%) and higher PRs (8.0% vs. 0).

CONCLUSION(S)

Our results suggest that in poorly responding patients, semen quality should remain the most important determinant when considering whether to perform ICSI. We have found that the values of 20 x 10(6)/mL and 35% motility are good predictors of success in such patients.