Intracytoplasmic sperm injection is not superior to conventional IVF in couples with non-male factor infertility and preimplantation genetic testing for aneuploidies (PGT-A)

Efficacy of intracytoplasmic sperm injection in women with non-male factor infertility: A systematic review and meta-analysis

INTRODUCTION

The use of intracytoplasmic sperm injection (ICSI) has dramatically increased in patients with non-male factor infertility during the last decades. However, whether ICSI provides a significant benefit over in vitro fertilization (IVF) in these patients is still controversial. In this study, we aimed to investigate the efficacy of ICSI on reproductive outcomes with non-male factor infertility and to provide updated evidence for clinical practice.

MATERIAL AND METHODS

We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials from inception to March 2023. Randomized controlled trials (RCTs) comparing the efficacy between ICSI and IVF in patients with non-male factor infertility were included. The main outcomes were the live birth rate (LBR), fertilization rate (FR), and total fertilization failure (TFF). The pooled estimates were calculated using the random-effects models as relative risk (RR) with 95% confidence intervals (CIs). This systematic review and meta-analysis was registered in PROSPERO (CRD42023427004).

RESULTS

We included 18 RCTs with 3249 cycles and 30 994 oocytes. The results demonstrated that ICSI reduced the risk of TFF (RR = 0.26, 95% CI: 0.13-0.50, I2  = 58%) and increased FR per oocyte inseminated/injected (RR = 1.14, 95% CI: 1.08-1.20, I2  = 69%), but it did not improve LBR (RR = 1.11, 95% CI: 0.94-1.30, I2  = 0%) or other outcomes compared with IVF. However, the difference in fertilization failure reduction between ICSI and IVF may be explained by different randomization methods (randomization based on patients vs. sibling oocytes). When considering only studies with randomization based on patients, we found no evidence of the difference between the groups (RR = 0.72, 95% CI: 0.48-1.06, I2  = 0%). Furthermore, no differences were observed in subgroup analyses based on other factors, including female age, study period, and controlled ovarian stimulation protocols.

CONCLUSIONS

Our findings suggest that ICSI leads to no difference in reproductive outcomes compared to IVF in patients with non-male factor infertility. Considering the cost and safety of ICSI, we have no evidence to support the routine use of ICSI in these populations. High-quality RCTs with large sample sizes will be needed to confirm our results and explore clinical and neonatal outcomes.

Intracytoplasmic sperm injection vs. in-vitro fertilization in couples in whom the male partners had a semen analysis within normal reference ranges: An open debate

During recent decades, the application of intracytoplasmic sperm injection has increased considerably worldwide, especially in couples with non-male factor infertility. However, several studies analyzing the broad use of intracytoplasmic sperm injection, even in cases with a normal semen analysis, have collectively demonstrated no benefits compared to conventional in-vitro fertilization. Currently, there is insufficient evidence to support the intracytoplasmic sperm injection technique vs. in-vitro fertilization in cases of poor ovarian response or a low number of oocytes collected, or in patients with advanced maternal age. Since the intracytoplasmic sperm injection technique is more operator-dependent and invasive, its use should only be recommended in cases of male-factor infertility. There is some evidence showing that intracytoplasmic sperm injection is linked with an increased risk of birth defects. Albeit this evidence is limited, and currently it is not possible to draw a firm conclusion on these concerns, we do believe that these risks should be rigorously investigated. Thus, this review aims to clarify the debate on the application of the intracytoplasmic sperm injection procedure, as compared to standard in-vitro fertilization, in those assisted reproductive technology cycles without a clear male factor infertility. Furthermore, we try to clarify whether intracytoplasmic sperm injection would result in a higher live birth rate than in-vitro fertilization, in couples with non-male factor infertility.

Investigation of the risk of paternal cell contamination in PGT and the necessity of intracytoplasmic sperm injection

ICSI is widely recommended for patients undergoing preimplantation genetic testing (PGT), but are sperm a potential source of paternal cell contamination in PGT? Semen samples were obtained from five normozoospermic men consenting to research. From each sample 1, 2, 4, 8 and 10 sperm were collected in PCR tubes and whole genome amplification according to PGT-A and PGT-SR processing protocols was undertaken. None of the 25 samples submitted (a total of 125 sperm) showed evidence of DNA amplification. Thus, paternal cell contamination resulting from using conventional in vitro fertilization (IVF) as the insemination method, carries a low risk of an adverse event or misdiagnosis in PGT-A. Due to the higher risk incurred with PGT-SR, clinics may wish to exercise increased caution and continue using ICSI, while PGT-M involves different processing protocols, presenting a different risk profile.

Reproductive outcomes with delayed blastocyst development: the clinical value of day 7 euploid blastocysts in frozen embryo transfer cycles

Embryos of optimal development reach blastocyst stage 116 ± 2 h after insemination. Usable D7 blastocysts represent nearly 5% of embryos in IVF with acceptable pregnancy and live birth rates, however data are still limited. Therefore, this study aimed to analyze the ongoing pregnancy rate (OPR) of D7 blastocysts in single euploid frozen embryo transfer (FET) cycles. An observational study was performed including 1527 FET cycles with blastocysts biopsied on D5 (N = 855), D6 (N = 636) and D7 (N = 36). Blastocysts were classified as good (AA/AB/BA), fair (BB) or poor (AC/BC/CC/CA/CB) (Gardner scoring). FETs were performed in natural cycles (NC) or hormone replacement therapy (HRT) cycles. Patient's age differed significantly between D5, D6 and D7 blastocysts FET cycles (33.2 ± 5.6, 34.4 ± 5.3 and 35.9 ± 5.2, P < 0.001). OPRs were higher when D5 euploid blastocysts were transferred compared with D6 and D7 (56.0% vs. 45.3% and 11.1%, P < 0.001). Poor quality blastocysts were predominant in D7 blastocyst FET cycles (good quality: 35.4%, 27.2%, 5.6%; fair quality: 52.1%, 38.5%, 11.1%; poor quality: 12.5%, 34.3%, 83.3%, P < 0.001 for D5, D6 and D7 blastocysts; respectively). OPR was significantly reduced by D7 blastocyst FETs (OR = 0.23 [0.08;0.62], P = 0.004), patient's BMI (OR = 0.96 [0.94;0.98], P < 0.001), HRT cycles (OR = 0.70 [0.56;0.88], P = 0.002) and poor quality blastocysts (OR = 0.33 [0.24;0.45], P < 0.001). OPR is significantly reduced with D7 compared with D5/D6 euploid blastocysts in FET cycles. The older the patient, the more likely they are to have an FET cycle with blastocysts biopsied on D7, therefore culturing embryos until D7 can be a strategy to increase OPR outcomes in patients ≥38 years.

Embryo Culture Medium Has No Impact on Mosaicism Rates: a Sibling Oocyte Study

Human embryos cultured in vitro can contain two or more cytogenetically distinct cell lineages known as "chromosomal mosaicism". Since mosaicism is produced by mitotic errors after fertilization occurs, culture conditions might contribute to mosaicism origins. Many studies demonstrated that euploidy rates are not affected by culture media; however, whether oocytes cultured under continuous culture media (CCM) or sequential culture media (SCM) has a higher risk of mosaicism occurring remains unsolved. Therefore, this study aims to determine whether mosaicism rates differ when sibling oocytes are cultured in CCM or SCM. A single center observational study was performed including 6072 sibling oocytes. Mature oocytes (MII) were inseminated and cultured in CCM (n = 3,194) or SCM (n = 2,359) until blastocyst stage for trophectoderm (TE) biopsy on day (D) 5, D6, or D7 for preimplantation genetic testing analysis with a semi-automated next-generation sequencing. Mosaicism was classified as low (30-50%) or high (50-80%) based on the percentage of abnormal cells constitution detected in TE samples. As a result, 426 women with a mean age of 34.7 ± 6.4 years were included in the study. Fertilization rates were comparable between CCM and SCM (74.0% vs 72.0%, p = 0.091). Although total blastulation rate and usable blastocyst rate (biopsied blastocysts) were significantly higher in CCM than SCM (75.3 % vs. 70.3%, p < 0.001 and 58.0% vs. 54.5%, p = 0.026), euploidy rates did not differ significantly (45.2% vs. 45.7%, p = 0.810, respectively). Mosaicism rate was not significantly different for blastocysts cultured in CCM or SCM (4.7% vs. 5.1%, p = 0.650), neither the proportion of low or high mosaic rates (3.7% vs. 4.4%, p = 0.353 and 1.0% vs. 0.7%, p = 0.355, respectively). Hence, it was concluded that CCM or SCM does not have an impact on mosaicism rate of embryos cultured until the blastocyst stage.

Conventional IVF is feasible in preimplantation genetic testing for aneuploidy

PURPOSE

To investigate the feasibility of the application of conventional in vitro fertilization (cIVF) for couples undergoing preimplantation genetic testing for aneuploidies (PGT-A) with non-male factor infertility.

METHODS

To evaluate the efficiency of sperm whole-genome amplification (WGA), spermatozoa were subjected to three WGA protocols: Picoplex, ChromInst, and multiple displacement amplification (MDA). In the clinical studies, 641 couples who underwent PGT-A treatment for frozen embryos between January 2016 and December 2021 were included to retrospectively compare the chromosomal and clinical outcomes of cIVF and intracytoplasmic sperm injection (ICSI). Twenty-six couples were prospectively recruited for cIVF and PGT-A treatment between April 2021 and April 2022; parental contamination was analyzed in biopsied samples; and 12 aneuploid embryos were donated to validate the PGT-A results.

RESULTS

Sperm DNA failed to amplify under Picoplex and ChromInst conditions but could be amplified using MDA. In frozen PGT-A cycles, no significant differences in the average rates of euploid, mosaic, and aneuploid embryos per cycle between the cIVF-PGT-A and ICSI-PGT-A groups were observed. The results of the prospective study that recruited couples for cIVF-PGT-A treatment showed no paternal contamination and one case of maternal contamination in 150 biopsied trophectoderm samples. Among the 12 donated embryos with whole-chromosome aneuploidy, 11 (91.7%) presented uniform chromosomal aberrations, which were in agreement with the original biopsy results.

CONCLUSIONS

Under the Picoplex and ChromInst WGA protocols, the risk of parental contamination in the cIVF-PGT-A cycles was low. Therefore, applying cIVF to couples with non-male factor infertility who are undergoing PGT-A is feasible.

Opening the black box: why do euploid blastocysts fail to implant? A systematic review and meta-analysis

BACKGROUND

A normal chromosomal constitution defined through PGT-A assessing all chromosomes on trophectoderm (TE) biopsies represents the strongest predictor of embryo implantation. Yet, its positive predictive value is not higher than 50-60%. This gap of knowledge on the causes of euploid blastocysts' reproductive failure is known as 'the black box of implantation'.

OBJECTIVE AND RATIONALE

Several embryonic, maternal, paternal, clinical, and IVF laboratory features were scrutinized for their putative association with reproductive success or implantation failure of euploid blastocysts.

SEARCH METHODS

A systematic bibliographical search was conducted without temporal limits up to August 2021. The keywords were '(blastocyst OR day5 embryo OR day6 embryo OR day7 embryo) AND (euploid OR chromosomally normal OR preimplantation genetic testing) AND (implantation OR implantation failure OR miscarriage OR abortion OR live birth OR biochemical pregnancy OR recurrent implantation failure)'. Overall, 1608 items were identified and screened. We included all prospective or retrospective clinical studies and randomized-controlled-trials (RCTs) that assessed any feature associated with live-birth rates (LBR) and/or miscarriage rates (MR) among non-mosaic euploid blastocyst transfer after TE biopsy and PGT-A. In total, 41 reviews and 372 papers were selected, clustered according to a common focus, and thoroughly reviewed. The PRISMA guideline was followed, the PICO model was adopted, and ROBINS-I and ROB 2.0 scoring were used to assess putative bias. Bias across studies regarding the LBR was also assessed using visual inspection of funnel plots and the trim and fill method. Categorical data were combined with a pooled-OR. The random-effect model was used to conduct the meta-analysis. Between-study heterogeneity was addressed using I2. Whenever not suitable for the meta-analysis, the included studies were simply described for their results. The study protocol was registered at http://www.crd.york.ac.uk/PROSPERO/ (registration number CRD42021275329).

OUTCOMES

We included 372 original papers (335 retrospective studies, 30 prospective studies and 7 RCTs) and 41 reviews. However, most of the studies were retrospective, or characterized by small sample sizes, thus prone to bias, which reduces the quality of the evidence to low or very low. Reduced inner cell mass (7 studies, OR: 0.37, 95% CI: 0.27-0.52, I2 = 53%), or TE quality (9 studies, OR: 0.53, 95% CI: 0.43-0.67, I2 = 70%), overall blastocyst quality worse than Gardner's BB-grade (8 studies, OR: 0.40, 95% CI: 0.24-0.67, I2 = 83%), developmental delay (18 studies, OR: 0.56, 95% CI: 0.49-0.63, I2 = 47%), and (by qualitative analysis) some morphodynamic abnormalities pinpointed through time-lapse microscopy (abnormal cleavage patterns, spontaneous blastocyst collapse, longer time of morula formation I, time of blastulation (tB), and duration of blastulation) were all associated with poorer reproductive outcomes. Slightly lower LBR, even in the context of PGT-A, was reported among women ≥38 years (7 studies, OR: 0.87, 95% CI: 0.75-1.00, I2 = 31%), while obesity was associated with both lower LBR (2 studies, OR: 0.66, 95% CI: 0.55-0.79, I2 = 0%) and higher MR (2 studies, OR: 1.8, 95% CI: 1.08-2.99, I2 = 52%). The experience of previous repeated implantation failures (RIF) was also associated with lower LBR (3 studies, OR: 0.72, 95% CI: 0.55-0.93, I2 = 0%). By qualitative analysis, among hormonal assessments, only abnormal progesterone levels prior to transfer were associated with LBR and MR after PGT-A. Among the clinical protocols used, vitrified-warmed embryo transfer was more effective than fresh transfer (2 studies, OR: 1.56, 95% CI: 1.05-2.33, I2 = 23%) after PGT-A. Lastly, multiple vitrification-warming cycles (2 studies, OR: 0.41, 95% CI: 0.22-0.77, I2 = 50%) or (by qualitative analysis) a high number of cells biopsied may slightly reduce the LBR, while simultaneous zona-pellucida opening and TE biopsy allowed better results than the Day 3 hatching-based protocol (3 studies, OR: 1.41, 95% CI: 1.18-1.69, I2 = 0%).

WIDER IMPLICATIONS

Embryo selection aims at shortening the time-to-pregnancy, while minimizing the reproductive risks. Knowing which features are associated with the reproductive competence of euploid blastocysts is therefore critical to define, implement, and validate safer and more efficient clinical workflows. Future research should be directed towards: (i) systematic investigations of the mechanisms involved in reproductive aging beyond de novo chromosomal abnormalities, and how lifestyle and nutrition may accelerate or exacerbate their consequences; (ii) improved evaluation of the uterine and blastocyst-endometrial dialogue, both of which represent black boxes themselves; (iii) standardization/automation of embryo assessment and IVF protocols; (iv) additional invasive or preferably non-invasive tools for embryo selection. Only by filling these gaps we may finally crack the riddle behind 'the black box of implantation'.

Comparison of clinical and preimplantation genetic testing for aneuploidy outcomes between in vitro fertilization and intracytoplasmic sperm injection in sibling mature oocytes from high-risk patients: A retrospective study

AIM

To evaluate the influence of insemination methods on clinical outcomes by assessing preimplantation genetic testing for aneuploidy (PGT-A) outcomes in embryos obtained using in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in sibling mature oocytes from high-risk patients.

METHODS

This retrospective study involved 108 couples with nonmale or mild male factor infertility who underwent split insemination cycles from January 2018 to December 2021. PGT-A was performed using trophectoderm biopsy, array comparative genome hybridization, or next-generation sequencing with 24-chromosome screening.

RESULTS

Mature oocytes were divided into IVF (n = 660) and ICSI (n = 1028) groups. The normal fertilization incidence was similar between the groups (81.1% vs. 84.6%). The total number of blastocysts biopsied was significantly higher in the IVF group than in the ICSI group (59.3% vs. 52.6%; p = 0.018). However, euploidy (34.4% vs. 31.9%) and aneuploidy (63.4% vs. 66.2%) rates per biopsy and clinical pregnancy rates (60.0% vs. 58.8%) were similar between the groups. Implantation (45.6% vs. 50.8%) and live birth or ongoing pregnancy (52.0% vs 58.8%) rates were slightly higher in the ICSI group than in the IVF group and miscarriage rate per transfer was slightly higher in the IVF group than in the ICSI group (12.0% vs 5.9%); however no significant difference was observed.

CONCLUSIONS

IVF and ICSI using sibling mature oocytes had similar clinical outcomes, and euploidy and aneuploidy rates in couples with nonmale and mild male factor infertility. These results suggest that IVF is a useful option, along with ICSI, as an insemination method in PGT-A cycles, especially in high-risk patients.

Impact of Multiple Vitrification-Warming Procedures and Insemination Methods on Pregnancy and Neonatal Outcomes in Preimplantation Genetic Testing for Aneuploidy

This study was to determine whether multiple vitrification-warming procedures and insemination method are associated with pregnancy and neonatal outcomes in preimplantation genetic testing for aneuploidy (PGT-A). This was a retrospective, single-center, observational study of 112 patients who underwent standard PGT-A practice and 154 patients who desired PGT-A for their vitrified unbiopsied blastocysts. A total of 97 euploid blastocysts biopsied and vitrified-warmed once and 117 euploid blastocysts biopsied once but vitrified-warmed twice (83 in vitro fertilization [IVF]-derived and 34 intracytoplasmic sperm injection [ICSI]-derived euploid blastocysts) were transferred. The primary outcome was the blastocyst survival rate for transfer, live birth rate, and neonatal outcomes. The results showed that an additional vitrification-warming procedure on blastocysts resulted in a lower but not statistically different survival rate for transfer. Compared with euploid blastocysts vitrified-warmed once, those vitrified-warmed twice provided statistically similar live birth rate. Neonatal outcomes, including the sex ratio, gestational age, birthweight, preterm birth rate, and low birthweight rate, did not differ between single and double vitrification. No significant differences were observed in rates of blastocyst survival, blastocyst euploid and live birth, and neonatal outcomes resulting from either conventional IVF or ICSI. The neonatal follow-up of babies live-born so far did not report any congenital malformations. In conclusion, an additional vitrification-warming on blastocysts had no detectable adverse impact on clinical outcomes after frozen-thawed single euploid blastocyst transfer in PGT-A cases; and ICSI did not confer any benefit in improving clinical outcomes compared with conventional IVF in cases requiring PGT-A on already vitrified nonbiopsied blastocysts.

Features of chromosomal abnormalities in relation to consanguinity: analysis of 10,556 blastocysts from IVF/ICSI cycles with PGT-A from consanguineous and non-consanguineous couples

Consanguineous marriage is defined as marriage between first or second-degree cousins, with high prevalence in many cultures and societies. Descendants from consanguineous unions have an increased risk for genetic diseases. Additionally, in consanguineous couples, chromosomal disjunction during embryogenesis could also be affected, increasing the risk of chromosomal errors. Nowadays, genomic testing allows to identify new genetic syndromes and variants related to copy-number variations (CNV), including whole chromosome, segmental and micro-segmental errors. This is the first study evaluating chromosomal ploidy status on blastocysts formed from consanguineous couples during IVF/ICSI treatments with Preimplantation Genetic Testing for Aneuploidies (PGT-A), compared to non-consanguineous couples. Although consanguine couples were significantly younger, no differences were observed between groups for fertilisation rate, blastulation rate and euploidy rate, once adjusted by age. Nevertheless, the number of blastocysts biopsied on day 5 was lower for consanguine couples. Segmental errors, and aneuploidies of chromosomes 13 and 14 were the most prominent abnormalities in relation to consanguinity, together with errors in chromosome 16 and sex chromosomes when the female partner was younger than 35. Once euploid blastocysts were considered for subsequent frozen embryo transfer, pregnancy outcomes were similar in both groups. The current findings point toward the fact that in consanguine unions, not only the risk of having a child with genetic disorders is increased, but also the risk of specific chromosomal abnormalities seems to be increased. Premarital counselling and tailored reproductive treatments should be offered to these couples.

Application of conventional IVF during preimplantation genetic testing for aneuploidies: a feasibility study

RESEARCH QUESTION

Is it feasible to apply conventional IVF to couples undergoing preimplantation genetic testing for aneuploidies (PGT-A) with non-severe male infertility?

DESIGN

The last wash fluid of biopsied trophectoderm (TE) cells was collected for whole genome amplification (WGA). A method was developed to determine parental contamination. Using single-nucleotide polymorphism (SNP) analysis, two standard curves were established; further mixtures were used for verification. Finally, 29 WGA products from couples undergoing conventional IVF were used to evaluate parental contamination.

RESULTS

The WGA results of the last wash fluid of biopsied TE cells revealed almost no free DNA. By adopting two strategies based on maternally and paternally biased SNP in the mixture, data from bioinformatics analysis were analysed to determine the relationship between maternal (Index M) and paternal (Index F) bias statistics. Two standard curves were successfully established based on these indices that allowed the prediction of maternal and parental contamination, which correlated well with actual ratios of known composition mixtures during validation. The average contamination level was 10.6% determined from 10 WGA products that featured maternal contamination, whereas that of the other 19 products that featured paternal contamination was less than 10%.

CONCLUSIONS

This study confirmed the feasibility of applying conventional IVF to couples undergoing PGT-A with non-severe male infertility.

Clinical and laboratory parameters associated with pregnancy outcomes in patients undergoing frozen euploid blastocyst transfer

RESEARCH QUESTION

Which factors impact on clinical pregnancy rate (CPR) and live birth rates (LBR) in euploid frozen embryo transfer (eFET) cycles?

DESIGN

Retrospective observational study including 1660 eFET cycles with 2439 euploid blastocysts, from November 2016 to December 2020. The impact of clinical and laboratory parameters on CPR, biochemical miscarriage rate (BMR), clinical miscarriage rate (CMR) and LBR was evaluated.

RESULTS

CPR per transfer was 63.4%, LBR per transfer 51.6%. CPR and LBR were significantly higher when double embryo transfer (DET) was performed (71.6% versus 57.7%, P < 0.001; 55.2% versus 49.1%, P = 0.016, respectively). However, pregnancy loss was significantly higher in the DET group (28.8% versus 22.8%, P = 0.02). When patients were classified by body mass index (BMI), no differences were observed for CPR, but CMR was lower (P < 0.001) and LBR higher (p = 0.031) for the normal BMI group. The natural cycle protocol revealed lower CMR (P < 0.001) and lower pregnancy loss (P < 0.001); subsequently, higher LBR (57.6%, 48.8%, 45.0%, P = 0.001) compared with hormonal replacement protocol and stimulated cycle. Day of trophectoderm biopsy affected CPR (P < 0.001) and LBR (P < 0.001), yet no differences were observed for BMR, CMR or pregnancy loss. The multivariate analysis showed that day 6/7 embryos had lower probabilities for pregnancy; overweight and obesity had a negative impact on LBR, and natural cycle improved LBR (adjusted odds ratio 1.445, 95% confidence interval 0.519-0.806).

CONCLUSIONS

Day of biopsy affected CPR, while BMI and endometrial preparation protocol were associated with LBR in eFET. DET should be discouraged as it will increase the risk of pregnancy loss. Women with higher BMI should be aware of the higher risk of pregnancy loss and lower LBR even though a euploid blastocyst is transferred.

What Does Intracytoplasmic Sperm Injection Change in Embryonic Development? The Spermatozoon Contribution

The intracytoplasmic sperm injection (ICSI) technique was invented to solve severe male infertility due to altered sperm parameters. Nowadays, it is applied worldwide for the treatment of couple infertility. ICSI is performed with any available spermatozoon from surgery or ejaculated samples, whatever are the sperm motility, morphology or quantity. The aim of the present review was to study if embryo development and kinetics would be modified by (1) ICSI under the technical aspects, (2) the micro-injected spermatozoa in connection with male infertility. From published data, it can be seen that ICSI anticipates the zygote kinetics Furthermore, because fertilization rate is higher in ICSI compared to conventional in vitro fertilization (IVF), more blastocysts are obtained for clinical use in ICSI. Sperm and spermatozoa characteristics, such as sperm parameters, morphology and vitality, DNA content (levels of sperm DNA fragmentation, microdeletions, and chromosomal abnormalities), RNA content, epigenetics, and sperm recovery site (testicular, epididymis, and ejaculated), have an impact on fertilization and blastocyst rates and embryo kinetics in different ways. Even though ICSI is the most common solution to solve couples' infertility, the causes of male infertility are crucial in building a competent spermatozoa that will contribute to normal embryonic development and healthy offspring.

Preimplantation genetic testing for human blastocysts with potential parental contamination using a quantitative parental contamination test (qPCT): an evidence-based study

RESEARCH QUESTION

Is it possible to develop a quantitative method for detecting parental DNA contamination in conventional IVF using preimplantation genetic testing for aneuploidy (PGT-A)?

DESIGN

In this study, a quantification method was established for the parental contamination test (qPCT), which ensured more reliable results, and then verified its effectiveness for vitrified conventional IVF embryos. A total of 120 surplus vitrified blastocysts from patients who underwent prior routine IVF cycles were available for study.

RESULTS

The results of the prospective clinical study of qPCT-PGT-A showed that the maternal contamination rate was 0.83% (1/120) and that the risk of paternal contamination was negligible. The 24 frozen embryo transfer cycles resulted in 16 clinical pregnancies, including 13 live births, one late inevitable miscarriage and two ongoing pregnancies.

CONCLUSIONS

The risk of PGT in embryos with potential parental contamination is relatively low, and PGT-A is applicable for vitrified conventional IVF embryos.

Metaphase-II oocyte competence is unlinked to the gonadotrophins used for ovarian stimulation: a matched case-control study in women of advanced maternal age

PURPOSE

An impact of different gonadotrophins selection for ovarian stimulation (OS) on oocyte competence has yet to be defined. In this study, we asked whether an association exists between OS protocol and euploid blastocyst rate (EBR) per metaphase-II (MII) oocytes.

METHODS

Cycles of first preimplantation genetic testing for aneuploidies conducted by women ≥ 35 years old with their own metaphase-II oocytes inseminated in the absence of severe male factor (years 2014-2018) were clustered based on whether recombinant FSH (rec-FSH) or human menopausal gonadotrophin (HMG) was used for OS, then matched for the number of fresh inseminated eggs. Four groups were outlined: rec-FSH (N = 57), rec-FSH plus rec-LH (N = 55), rec-FSH plus HMG (N = 112), and HMG-only (N = 127). Intracytoplasmic sperm injection, continuous blastocyst culture, comprehensive chromosome testing to assess full-chromosome non-mosaic aneuploidies and vitrified-warmed euploid single embryo transfers (SETs) were performed. The primary outcome was the EBR per cohort of MII oocytes. The secondary outcome was the live birth rate (LBR) per first SETs.

RESULTS

Rec-FSH protocol was shorter and characterized by lower total gonadotrophin (Gn) dose. The linear regression model adjusted for maternal age showed no association between the Gn adopted for OS and EBR per cohort of MII oocytes. Similarly, no association was reported with the LBR per first SETs, even when adjusting for blastocyst quality and day of full blastulation.

CONCLUSION

In view of enhanced personalization in OS, clinicians shall focus on different endpoints or quantitative effects related to Gn action towards follicle recruitment, development, and atresia. Here, LH and/or hCG was administered exclusively to women with expected sub/poor response; therefore, we cannot exclude that specific Gn formulations may impact patient prognosis in other populations.

Clinical application of noninvasive chromosomal screening for elective single-blastocyst transfer in frozen-thawed cycles

BACKGROUND

The objective of this study was to explore the clinical application of noninvasive chromosomal screening (NICS) for elective single-blastocyst transfer (eSBT) in frozen-thawed cycles.

METHODS

This study retrospectively analysed the data of 212 frozen-thawed single-blastocyst transfers performed in our centre from January 2019 to July 2019. The frozen embryos were selected based on morphological grades and placed in preincubation for 6 h after warming. Then spent microdroplet culture media of frozen-thawed blastocysts were harvested and subjected to NICS. The clinical outcomes were evaluated and further stratified analysis were performed, especially different fertilization approaches.

RESULTS

The clinical pregnancy, ongoing pregnancy, and live birth rates in the euploidy group were significantly higher than those in the aneuploidy group (56.2% versus 29.4%) but were nonsignificantly different from those in the chaotic abnormal/NA embryos group (56.2% versus 60.4%). Compared with day6 (D6) blastocysts, D5 blastocysts had a nonsignificantly different euploidy rate (40.4% versus 48.1%, P = 0.320) but significantly increased clinical pregnancy (57.7% versus 22.2%, P < 0.001), ongoing pregnancy (48.1% versus 14.8%, P < 0.001), and live birth rates (48.1% versus 13.0%, P < 0.001). The percentage of chaotic abnormal/NA embryos group was significantly higher among D5 embryos than among D6 embryos (30.1% versus 11.1%, P = 0.006). The percentage of aneuploid embryos was higher among the embryos with lower morphological quality(21.5% among 'good' embryos versus 34.6% among 'fair' embryos versus 46.0% among 'poor' embryos, P = 0.013); correspondingly, the overall clinical pregnancy, ongoing pregnancy and live birth rate rates showed similar declines.

CONCLUSIONS

NICS combined with morphological assessment is an effective tool to guide frozen-thawed SBT. The optimal embryo for SBT is a 'euploid embryo with good morphology', followed sequentially by a 'chaotic abnormal/NA embryo with good morphology', 'euploid embryo with fair morphology', and 'chaotic abnormal/NA embryo with fair morphology'.

Impact of intracytoplasmic sperm injection in women with non-male factor infertility: A systematic review and meta-analysis

OBJECTIVE

The purpose of this study is to determine whether intracytoplasmic sperm injection (ICSI) is beneficial in patients with non-male factor infertility.

METHODS

This systematic review and meta-analysis included articles from inception to May 2022. Published studies of non-male factor infertile women undergoing ICSI or in vitro fertilization (IVF) included in PubMed, Embase, web of science, Wanfang Database, and CNKI were searched by computer, without language restrictions. A random-effect model was applied to calculate the risk ratios (RRs) and their 95% confidence intervals (CIs). Letters, case reports, and review articles including meta-analyses and expert opinions were excluded. The primary endpoints were laboratory outcomes and pregnancy outcomes. The Secondary endpoints were neonatal outcomes.

RESULTS

Six randomized controlled studies and 20 retrospective cohort studies met the inclusion criteria. In meta-analytic forest plots, compared with IVF, those who received ICSI treatment were not different in fertilization rate (RR = 0.99, 95% CI [0.90-1.09], P = 0.88), total fertilization failure rate (RR = 1.30, 95% CI [1.17-1.45], P < 0.00001), and good quality embryo rate (RR = 0.94, 95% CI [ 0.86-1.02], P = 0.15), clinical pregnancy rate (RR = 0.84, 95% CI [0.70-1.01], P = 0.06), live birth rate (RR = 0.89, 95% CI [0.77-1.03], P = 0.13), miscarriage rate (RR = 1.06, 95% CI [0.78-1.43], P = 0.71), preterm neonatal delivery rate (RR = 0.92, 95% CI [0.67-1.26], P = 0.61), and low neonatal weight rate (RR = 1.13, 95% CI [0.80-1.61], P = 0.48). However, the implantation rate of IVF was better than ICSI (RR = 0.77, 95% CI [0.64-0.93], P = 0.005). In the subgroup analysis of the live birth rate of fresh embryo transfer, IVF performed in those ≥35 years had a higher live birth rate (RR = 0.82, 95% CI [0.78-0.83], P < 0.001).

CONCLUSION

The findings of this study indicate that ICSI is not superior to IVF in the treatment of infertility related to non-male factors. In order to confirm this result, more high-quality clinical studies are needed.

Opportunities and Limits of Conventional IVF versus ICSI: It Is Time to Come off the Fence

Conventional IVF (c-IVF) is one of the most practiced assisted reproductive technology (ART) approaches used worldwide. However, in the last years, the number of c-IVF procedures has dropped dramatically in favor of intracytoplasmic sperm injection (ICSI) in cases of non-male-related infertility. In this review, we have outlined advantages and disadvantages associated with c-IVF, highlighting the essential steps governing its success, its limitations, the methodology differences among laboratories and the technical progress. In addition, we have debated recent insights into fundamental questions, including indications regarding maternal age, decreased ovarian reserve, endometriosis, autoimmunity, single oocyte retrieval-cases as well as preimplantation genetic testing cycles. The “overuse” of ICSI procedures in several clinical situations of ART has been critically discussed. These insights will provide a framework for a better understanding of opportunities associated with human c-IVF and for best practice guidelines applicability in the reproductive medicine field.

V, Joseph D, Meitei HY, Asampille G, Kumar P, Gowda G. A. N, Kalthur G, Kovacic B, Adiga SK. ICSI in non-male factor infertility patients does not alter metabolomic signature in sibling embryos as evidenced by sensitivity enhanced nuclear magnetic resonance (NMR) spectroscopy

Intracytoplasmic sperm injection (ICSI) was developed to overcome male factor infertility, however, there recently has been an increasing trend in ICSI usage irrespective of the etiology, demonstrating an overuse of this insemination technique. There is a limited knowledge on the behaviour of ICSI derived embryos in non-male factor infertility patients. Metabolomic assessment of preimplantation embryos in conjunction with morphological evaluation can provide better understanding of embryonic behaviour. Hence, this study was undertaken to explore if there are any metabolomic differences between IVF and ICSI derived sibling day-5 blastocysts from non-male factor infertility patients. This prospective study included nineteen couples with non-male factor infertility undergoing Assisted Reproductive Technology. The sibling oocytes retrieved from each patient were randomly assigned to two groups and inseminated either by IVF or ICSI. Spent culture media (SCM) in which embryos were cultured up to day 5 were collected and investigated using sensitivity enhanced NMR based metabolite profiling utilizing high resolution (800 MHz) NMR equipped with cryogenically cooled micro-coil (1.7 mm) probe. The metabolomic signature between IVF and ICSI derived sibling blastocysts was assessed. A significant reduction in the concentrations of pyruvate, citrate, glucose and lysine were observed in both IVF and ICSI sibling embryos compared to medium control (P< 0.05–0.001). Further, histidine and valine level was found lower in ICSI embryos compared to medium control (P<0.05) during 96 hours of in vitro culture. Notably, between IVF and ICSI SCM, no significant difference in the concentration of the metabolites was found. Our results suggest that ICSI in non-male factor does not alter the SCM metabolomic signature during 96 hours of embryonic development.

Non-invasive preimplantation genetic testing for conventional IVF blastocysts

BACKGROUND

Previous studies suggested that non-invasive preimplantation genetic testing (niPGT) for intracytoplasmic sperm injection (ICSI) blastocysts can be used to identify chromosomal ploidy and chromosomal abnormalities. Here, we report the feasibility and performance of niPGT for conventional in vitro fertilization (IVF) blastocysts.

METHODS

This was a prospective observational study. In the preclinical stage, whole genome amplification and NGS were performed using the sperm spent culture medium (SCM). Then, trophectoderm (TE) biopsies and corresponding SCM derived from 27 conventional IVF monopronuclear embryos were collected. In the clinical stage, samples from 25 conventional IVF cycles and 37 ICSI cycles from April 2020-August 2021 were collected for performance evaluation.

RESULTS

Preclinically, we confirmed failed sperm DNA amplification under the current amplification system. Subsequent niPGT from the 27 monopronuclear blastocysts showed 69.2% concordance with PGT results of corresponding TE biopsies. In the clinical stage, no paternal contamination was observed in any of the 161 SCM samples from conventional IVF. While maternal contamination was observed in 29.8% (48/161) SCM samples, only 2.5% (4/161) samples had a contamination ratio ≥ 50%. Compared with that of TE biopsy, the performances of NiPGT from 161 conventional IVF embryos and 122 ICSI embryos were not significantly different (P > 0.05), with ploidy concordance rates of 75% and 74.6% for IVF and ICSI methods, respectively. Finally, evaluation of the euploid probability of embryos with different types of niPGT results showed prediction probabilities of 82.8%, 77.8%, 62.5%, 50.0%, 40.9% and 18.4% for euploidy, sex-chromosome mosaics only, low-level mosaics, multiple abnormal chromosomes, high-level mosaics and aneuploidy, respectively.

CONCLUSIONS

Our research results preliminarily confirm that the niPGT approach using SCM from conventional IVF has comparable performance with ICSI and might broadening the application scope of niPGT.

Validation of Non-Invasive Preimplantation Genetic Screening Using a Routine IVF Laboratory Workflow

Embryo selection is needed to optimize the chances of pregnancy in assisted reproduction technology. This study aimed to validate non-invasive preimplantation genetic testing for aneuploidy (niPGT-A) using a routine IVF laboratory workflow. Can niPGT-A combined with time-lapse morphokinetics provide a better embryo-selection strategy? A total of 118 spent culture mediums (SCMs) from 32 couples were collected. A total of 40 SCMs and 40 corresponding trophectoderm (TE) biopsy samples (n = 29) or arrested embryos (n = 11) were assessed for concordance. All embryos were cultured to the blastocyst stage (day 5 or 6) in a single-embryo culture time-lapse incubator. The modified multiple annealing and looping-based amplification cycle (MALBAC) single-cell whole genome amplification method was used to amplify cell-free DNA (cfDNA) from the SCM, which was then sequenced on the Illumina MiSeq system. The majority of insemination methods were conventional IVF. Low cfDNA concentrations were noted in this study. The amplification niPGT-A and conventional PGT-A was 67.7%. Based on this study, performing niPGT-A without altering the daily laboratory procedures cannot provide a precise diagnosis. However, niPGT-A can be applied in clinical IVF, enabling the addition of blastocysts with a better prediction of euploidy for transfer.

Marginal differences in preimplantation morphokinetics between conventional IVF and ICSI in patients with preimplantation genetic testing for aneuploidy (PGT-A): A sibling oocyte study

Objective

This study aimed to analyze the morphokinetic behaviour between conventional IVF and ICSI, in cycles with preimplantation genetic testing for aneuploidies (PGT-A).

Materials

A randomized controlled trial (NCT03708991) was conducted in a private fertility center. Thirty couples with non-male factor infertility were recruited between November 2018 and April 2019. A total of 568 sibling cumulus oocyte complexes were randomly inseminated with conventional IVF and ICSI and cultured in an Embryoscope time-lapse system. The morphokinetic behaviour of IVF/ICSI sibling oocytes was analysed as primary endpoint. As secondary endpoints, morphokinetic parameters that predict blastocysts that will be biopsied, the day of biopsy, gender and euploid outcome was assessed.

Results

When comparing IVF to ICSI, only the time to reach the 2-cell stage (t2) was significantly delayed for IVF embryos: OR: 1.282 [1.020–1.612], p = 0.033. After standardizing for tPNf (ct parameters), only Blast(tStartBlastulation-t2) remained significant: OR: 0.803 [0.648–0.994], p = 0.044. For the analysis of zygotes that will be biopsied on day 5/6 versus zygotes without biopsy, only early morphokinetic parameters were considered. All parameters were different in the multivariate model: ct2: OR: 0.840 [0.709–0.996], p = 0.045; ct6: OR: 0.943 [0.890–0.998], p = 0.043; cc2(t3-t2): OR: 1.148 [1.044–1.263], p = 0.004; cc3(t5-t3): OR: 1.177 [1.107–1.251], p<0.0001. When comparing the development between blastocysts biopsied on day 5 versus day 6, only three morphokinetic parameters were significant: cc2(t3-t2): OR: 1.394 [1.010–1.926], p = 0.044; ctBlastocyst: OR: 0.613 [0.489–0.768], p<0.0001 and ctExpandedBlastocyst: OR: 0.913 [0.868–0.960], p = 0.0004. Multivariate analysis of gender and ploidy did not reveal differences in morphokinetic behaviour.

Conclusion

Minor morphokinetic differences are observed between IVF and ICSI. Early in the development, distinct cleavage patterns are observed between embryos that will be biopsied or not.

Optimizing embryological aspects of oocyte retrieval, oocyte denudation, and embryo loading for transfer: a state of the art review

Oocyte retrieval, oocyte denudation, and embryo transfer are crucial processes during assisted reproduction (ART). Air quality in the ART laboratory, temperature, pH of the media used and the time interval between oocyte retrieval and insemination are all critical factors. Anesthesia is required for oocyte retrieval, however evidence regarding the potential impact of different methods (general anesthesia, conscious sedation, and local anesthesia) on the clinical outcomes is unclear. The optimal timing of oocyte denudation following retrieval has not been established. Regarding the mechanical denudation process, there is a lack of evidence to demonstrate the safest minimum inner diameter of denuding pipettes used to complete the removal of granulosa cells surrounding the oocytes. During embryo transfer, many clinics worldwide flush the catheter before embryo loading, in an attempt to potentially rinse off any toxic agents; however, there is insufficient evidence to show that flushing the embryo transfer catheter before loading increases the success of ART outcome. Considering the serious gaps in knowledge in ART practice, the aim of this review is to provide an updated overview of the current knowledge regarding the various steps and techniques involved in oocyte retrieval, oocyte denudation, and embryo loading for transfer.

Effectivity of conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) when male factor is absent: a perspective point of view

An objective and individualized approach of in vitro fertilization techniques tends to decrease costs and improve the experience of infertile couples during treatment. The use of available technologies to diagnose and treat infertility based on scientific evidence seems to be the best practice, which is the guideline that motivates this review on the available techniques for laboratory oocyte insemination. Conventional IVF, the pioneering technique, was initially used in the treatment of tubal obstruction infertility, successfully expanding the treatment of infertile couples presenting with several other factors. However, it was less effective in cases of severe male factor infertility. Intracytoplasmic sperm injection, which was developed in 1992, proved to be the method of choice for treating couples with severe male factor infertility. Since then, it has been increasingly used regardless of the infertility factor. This review discusses the effectiveness of conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) when the male factor is absent in all aspects, as technical and clinical outcomes, associated risks, adjustments for using with other technologies and costs. Finally we discuss the advantages and disadvantages of each one, with all aspects reviewed.

The Spiny Mouse—A Menstruating Rodent to Build a Bridge From Bench to Bedside

Menstruation, the cyclical breakdown of the uterine lining, is arguably one of evolution's most mysterious reproductive strategies. The complexity and rarity of menstruation within the animal kingdom is undoubtedly a leading contributor to our current lack of understanding about menstrual function and disorders. In particular, the molecular and environmental mechanisms that drive menstrual and fertility dysregulation remain ambiguous, owing to the restricted opportunities to study menstruation and model menstrual disorders in species outside the primates. The recent discovery of naturally occurring menstruation in the Egyptian spiny mouse (Acomys cahirinus) offers a new laboratory model with significant benefits for prospective research in women's health. This review summarises current knowledge of spiny mouse menstruation, with an emphasis on spiral artery formation, inflammation and endocrinology. We offer a new perspective on cycle variation in menstrual bleeding between individual animals, and propose that this is indicative of fertility success. We discuss how we can harness our knowledge of the unique physiology of the spiny mouse to better understand vascular remodelling and its implications for successful implantation, placentation, and foetal development. Our research suggests that the spiny mouse has the potential as a translational research model to bridge the gap between bench to bedside and provide improved reproductive health outcomes for women.

Monopronucleated (1PN) and tripronuclear (3PN) zygotes formation during assisted reproduction in POSEIDON group 4 patients: Emphasizing on polar bodies

AIM

Abnormal fertilization (1PN/3PN) and its accompanying polar body (PB) conditions have been less discussed in poor ovarian responders. By observing the PBs, we analyzed the mechanisms of abnormal fertilization and aimed to explore the role of intracytoplasmic sperm injection/in vitro fertilization (ICSI/IVF) in POSEIDON group 4 patients.

METHODS

An observational study. All fresh IVF/ICSI cycles from January 2018 to December 2019 were evaluated. The inclusion criteria were POSEIDON group 4. Fertilization and PB conditions were assessed 16-18 h post-insemination. Primary observation endpoints including normal fertilization, abnormal fertilization, and total fertilization failure rate.

RESULTS

A total of 351 cycles involving 180 patients met the inclusion criteria. Of these, 15 cycles reported no retrieved oocytes. Finally, 336 cycles (IVF, n = 267; ICSI, n = 69) were included. A total of 1005 oocytes and 939 embryos were assessed. The mean female age was 40.8 years, and the mean AMH level was 0.6 ng/mL. The normal fertilization rate was 69.7%. The zygote distribution was 18.7% 0PN, 3.9% 1PN, 66.9% 2PN, 9.5% 3PN, and 1.0% ≥4PN. For 1PN zygotes, 59% were denoted as 1PN2PB. The mean 3PN rate was 8.9%.

CONCLUSIONS

In POSEIDON group 4, most of the monopronucleated zygotes were 1PN2PB. Digyny (3PN1PB), due to failure to extrude the second PB, was the major cause of triploidy in which ICSI could not circumvent. The distribution of abnormally fertilized zygotes was similar in IVF and ICSI. To investigate the mechanisms of abnormal fertilization and assess whether ICSI is necessary, analysis of PB will provide important clues.

Comparison of in vitro fertilisation/intracytoplasmic sperm injection on live birth rates in couples with non-male factor infertility and advanced maternal age

PURPOSE

To determine if the use of ICSI in women of advanced maternal age with non-male factor infertility increases chances of live birth.

METHODS

Retrospective data analysis of 10 years of cycle data from a single Australian IVF clinic (Repromed). First cycle patients only of an advanced maternal age (≥ 35 years) with non-male factor infertility utilising standard IVF or ICSI insemination and having at least three oocytes collected at egg pick up were assessed for live birth following transfer of single genetically unscreened blastocyst (N = 577). Subanalysis of clinical pregnancy, miscarriage, fertilisation, embryo utilisation rate and having a blastocyst for transfer were considered. Unadjusted, covariate adjusted and propensity score weighted analysis were performed.

RESULTS

The use of standard IVF insemination in women ≥ 35 years with non-male factor infertility increased the chance of a live birth compared with ICSI insemination (unadjusted OR = 2.72, 95% CI [1.78, 4.17]; adjusted OR = 2.64, 95% CI [1.64, 4.27] and weighted OR = 2.26, 95% CI [1.72, 2.98] 31% vs 14%). All other outcomes (fertilisation rate, embryo utilisation, blastocyst for embryo transfer and miscarriage rate) were unaffected.

CONCLUSION

In couples with advanced maternal age and non-male factor infertility, standard IVF insemination appears to increase the chance of a live birth compared with ICSI. As such, the results of this study support the use of routine IVF as the preferred insemination technique for older women in non-male factor infertility. However, future randomised controlled trials are still required to assess this policy.

ICSI for non-male factor: do we practice what we preach?

Since its introduction in 1992, intracytoplasmic sperm injection (ICSI) has revolutionized the treatment of infertility due to severe male factor. Over the last three decades, the use of ICSI for non-male factor has increased dramatically, despite guidelines to the contrary from professional societies. Excessive utilization of ICSI is primarily due to an irrational fear of total fertilization failure, which is at odds with rational evidence to support its use.

Is Intracytoplasmic Sperm Injection the Solution for all in Unexplained Infertility?

Intracytoplasmic sperm injection (ICSI) was first introduced as a supplemental method to conventional in vitro fertilization (c-IVF) for couples with severe male factor infertility to overcome the poor fertilization rate, while its indications expanded in current clinical practice and gained worldwide popularity. However, ICSI is invasive and crosses all natural barriers, raising several unresolved concerns regarding procedure-dependent and procedure-independent risks, as well as the characteristic of being labor-intensive and more expensive than c-IVF. This review is aimed to draw readers' attention, to the widespread use of ICSI worldwide, with its effectiveness in different indications of infertility, especially in those with unexplained infertility, as well as the cost-effectiveness of the ICSI-for-all strategy. Also, we covered current evidence on the short- and long-term safety of children born thanks to ICSI-aided conception. Further well-designed, adequately powered, and randomized controlled clinical trials are absolutely needed to arrive at a consensus on the use of ICSI over c-IVF in different populations.

The role of ICSI vs. conventional IVF for patients with advanced maternal age-a randomized controlled trial

OBJECTIVES

This study aimed to evaluate the role of intracytoplasmic sperm injection (ICSI) in the treatment of non-male factor infertile patients aged ≥ 39.

METHODS

This is a single-center, prospective, randomized controlled clinical trial, between March 2018 and December 2019. Sixty-nine patients were recruited, and sixty patients participated in the study. Their ovaries were randomized prior to the beginning of the ovarian stimulation: the oocytes from one side (n = 257) were allocated to the ICSI (ICSI arm), while those of the contralateral side (n = 258) were allocated to conventional insemination (IVF arm). The fertilization rate per oocyte retrieved, number of zygotes (2PN), and cleavage-stage embryos were assessed and compared between the two study groups.

RESULTS

The average number of zygotes (3.1 vs. 2.7 p = 0.45), the fertilization rate (72.4% vs. 65.1% p = 0.38), the average number of cleavage-stage (2.8 vs. 2.4 p = 0.29), and the average top-quality embryos (TQE) cleavage-stage embryos (1.7 vs. 1.6 p = 0.94) were comparable between the two groups. The TQE rate per randomized oocyte (41.2% vs. 41% p = 0.8) was also similar in both groups.

CONCLUSIONS

ICSI does not improve the reproductive outcomes of advanced-age patients undergoing conventional insemination for non-male factor infertility.

TRIAL REGISTRATION

NCT03370068.