使用波長為 498-563 nm 的綠色濾光片對胚胎發育率、形態品質或發育第 7 天和第 8 天的總細胞計數均無影響。

綠色濾光片對有害的藍光和紅外光具有保護作用。可降低壓力誘導型 Hsp72

綠色濾光片似乎可以降低體外受精 過程中光引起的刺激壓力‧

. 2009 Feb;24(2):308-14.

 doi: 10.1093/humrep/den432. Epub 2008 Dec 3.

Viability of bovine embryos following exposure to the green filtered or wider bandwidth light during in vitro embryo production

Background: Microscopic light during in vitro production (IVP) is a common stress factor compromising embryo development and viability. Many studies discussing detrimental effects of light have been conducted on in vivo matured/fertilized oocytes or on flushed embryos that were exposed to light only when cultured in vitro. The aim of this work was to examine the effects of light composition during all IVP steps on subsequent embryo development and quality. Methods: We compared the effects of a green pass filter of 498-563 nm wavelength, and a wider bandwidth of stereomicroscopic light on bovine embryo development rates, total cell counts and the presence of constitutive (Hsp73) and stress-inducible (Hsp72) forms of the Hsp70 protein. Results: The use of the green filter had no effect on embryo development rates, morphological quality or total cell counts on Day 7 or 8 of development compared with control group. However, Hsp72/73 protein levels revealed the protective effect of the filter against harmful blue and infrared regions of the light. The constitutive form Hsp73 was seen in both groups, but the inducible stress-response form Hsp72 was absent from the filter group embryos and appeared only in the group exposed to the stereomicroscopic light.

Conclusions: An easy to use and inexpensive green filter seems to reduce the stress caused by light during the IVP procedures without affecting either the accuracy of embryo monitoring or the need to increase the light intensity.

高精子DNA碎片SDF與節段性染色體非整倍體的發生率和父系全染色體非整倍體的增加有關

. 2023 Jun 23;166(2):117-124.

 doi: 10.1530/REP-23-0011. Print 2023 Aug 1.

The effect of sperm DNA fragmentation on the incidence and origin of whole and segmental chromosomal aneuploidies in human embryos

In brief: Whether sperm DNA fragmentation (SDF) affects embryo development and clinical outcomes is still controversial, which limits the utility of SDF testing in assisted reproductive technology management. This study demonstrates that high SDF is associated with the incidence of segmental chromosomal aneuploidy and increased paternal whole chromosomal aneuploidies. Abstract: We aimed to investigate the correlation of sperm DNA fragmentation (SDF) with the incidence and paternal origin of whole and segmental chromosomal aneuploidies of embryos at the blastocyst stage. A retrospective cohort study was conducted with a total of 174 couples (women aged 35 years or younger) who underwent 238 cycles (including 748 blastocysts) of preimplantation genetic testing for monogenic diseases (PGT-M). All subjects were divided into two groups based on the sperm DNA fragmentation index (DFI) level: low DFI (<27%) and high DFI (≥27%). The rates of euploidy, whole chromosomal aneuploidy, segmental chromosomal aneuploidy, mosaicism, parental origin of aneuploidy, fertilization, cleavage, and blastocyst formation were compared between low- and high-DFI groups. We found no significant differences in fertilization, cleavage, or blastocyst formation between the two groups. Compared to that in the low-DFI group, segmental chromosomal aneuploidy rate was significantly higher in the high-DFI group (11.57% vs 5.83%, P = 0.021; OR: 2.32, 95% CI: 1.10-4.89, P = 0.028). The whole chromosomal embryonic aneuploidy of paternal origin was significantly higher in cycles with high DFI than in cycles with low DFI (46.43% vs 23.33%, P = 0.018; OR: 4.32, 95% CI: 1.06-17.66, P = 0.041). However, the segmental chromosomal aneuploidy of paternal origin was not significantly different between the two groups (71.43% vs 78.05%, P = 0.615; OR: 1.01, 95% CI: 0.16-6.40, P = 0.995). In conclusion, our results suggested that high SDF was associated with the incidence of segmental chromosomal aneuploidy and increased paternal whole chromosomal aneuploidies in embryos.

胚胎非整倍體發生率不受禁慾時間、精子參數或精液來源的影響。

精子來源和品質相關的許多因素，對胚胎非整倍體發生率的影響甚微。

Cent European J Urol . 2019;72(3):296-301. doi: 10.5173/ceju.2019.1900. Epub 2019 Sep 2.

Paternal contribution to embryonic competence

Introduction: The effect of paternal characteristics on embryo development and the outcome of preimplantation genetic testing for aneuploidy have not been extensively explored. This study investigates the association of sperm parameters, insemination, and extraction techniques, with the rate of embryo aneuploidy. This study sought to evaluate the association between male factor infertility and embryo aneuploidy. Material and methods: Patients underwent in vitro fertilization using intracytoplasmic sperm injection, with preimplantation genetic testing for aneuploidy. Patients were divided into four groups by sperm parameters: Group A: oligozoospermia (sperm concentration <10 million, morphology > 4%); Group B: teratozoospermia (sperm concentration >10 million, morphology <4%); Group C: oligozoospermia and teratozoospermia (sperm concentration <10 million, morphology <4%); Group D: controls. Additionally, couples were divided into three categories by days of abstinence: Group A: <2; Group B: 2-7; and Group C: >7. Results: A total of 4108 in vitro fertilization cycles with preimplantation genetic testing for aneuploidy were analyzed. After controlling for parental age and follicle count, the rate of embryo aneuploidy was not affected by duration of abstinence, sperm parameters, or the source of the sperm sample. Conclusions: Numerous factors related to sperm source and quality were evaluated, and a minimal influence on the rate of embryo aneuploidy was observed.

(a) 第3天胚胎移植的患者，在胚胎移植前24小時進行測量子宮內膜PGE2 and PGF2a。

---懷孕VS 未懷孕率PGE2 and PGF2a有明顯差異

(b)  第天5胚胎移植的患者，

---懷孕VS 未懷孕率 PGE2 and PGF2a較無明顯差異

 

Figure 29.3 PGE2 and PGF2a concentrations in endometrial fluid (EF) predict successful

pregnancy outcome. Pilot study to determine the detection sensitivity and specificity of PGE2

and PGF2a concentrations in endometrial fluid obtained 24 hours before embryo transfer in NP

and P women. (a) In in vitro fertilization patients undergoing day-3 embryo transfer,

measurement is taken 24 hours before embryo transfer. (b) In ovum recipients undergoing day-

5 embryo transfer, measurement is taken 24 hours before embryo transfer. Abbreviations: NP,

non-pregnant; P, pregnant.

完全孵化（FH）囊胚 VS 未完全孵化（NFH）囊胚

------囊胚著床率無明顯不同

. 2016 Nov;31(11):2458-2470.

 doi: 10.1093/humrep/dew205. Epub 2016 Sep 12.

Hatching status before embryo transfer is not correlated with implantation rate in chromosomally screened blastocysts

Study question: Do the reproductive outcomes from the transfer of fully hatched (FH) blastocysts differ from those of not fully hatched (NFH) blastocysts?

Summary answer: Biochemical pregnancy rate (BPR), implantation rate (IR), live birth rate (LBR) and early pregnancy loss (EPL) rate are similar in FH and NFH single euploid blastocyst embryo transfers.

What is known already: The use of extended culture and PGS often leads to transfer of an embryo that is well developed and frequently FH from the zona pellucida. Without the protection of the zona, an FH embryo could be vulnerable to trauma during the transfer procedure. To date, no other study has evaluated the reproductive competence of an FH blastocyst transfer.

Study design, size, duration: The retrospective study included 808 patients who underwent 808 cycles performed between September 2013 and July 2015 at a private academic IVF center. Of these, 436 cycles entailed transfer of a NFH blastocyst (n = 123 fresh transfer, n = 313 frozen/thawed embryo transfer (FET)) and 372 cycles entailed transfer of an FH blastocyst (n = 132 fresh, 240 FET). Fresh and FET cycles and associated clinical outcomes were considered separately. LBR was defined as the delivery of a live infant after 24 weeks of gestation.

Participants/materials, setting, method: Trophectoderm biopsies were performed on Day 5 (d5) or 6 (d6) for embryos meeting morphology eligibility criteria (set at ≥3BC). Morphologic grading was determined using a modified Gardner-Schoolcraft scale prior to transfer. A single euploid embryo was selected for transfer per cycle on either the morning of d6, for fresh transfers or 5 days after progesterone supplementation for patients with transfer in an FET cycle. Embryos were classified as NFH (expansion Grade 3, 4 or 5) or FH (expansion Grade 6) cohorts. The main outcome measure was IR.

Main results and the role of chance: In the fresh transfer group, IR was similar between NFH and FH cycles (53.7% versus 55.3%, P = 0.99, odds ratio (OR) 0.9; 95% confidence interval (CI) 0.6-1.5). Secondary outcomes were also statistically similar between groups: BPR (65.9% versus 66.7%, OR 1.0; 95% CI: 0.6-1.6), LBR (43.1% versus 47.7%, P = 0.45, OR 1.2; 95% CI: 0.7-1.9) and EPL rate (22.8% versus 18.2%, OR 1.3; 95% CI: 0.7-2.4). After adjusting for age, BMI, endometrial thickness at the LH surge and oocytes retrieved in a logistic regression (LR) model, the hatching status remained not associated with IR (P > 0.05). In the FET cycles, IR was similar between NFH and FH cycles (62.6% versus 61.7%, OR 1.0; 95% CI: 0.7-1.5). Secondary outcomes were similar between groups: BPR (74.1% versus 72.9%, respectively, OR 1.1; 95% CI: 0.7-1.6), LBR (55.0% versus 50.0%, OR 0.8; 95% CI: 0.6-1.1) and EPL rate (18.9% versus 22.9%, respectively, OR 0.8; 95% CI: 0.5-1.2). After adjusting for age, BMI, endometrial thickness at the LH surge and oocytes retrieved in an LR model, the hatching status was not shown to be associated with implantation (P > 0.05).

比較（A）黃體素補充 &注射促排卵後第 6 天（第 0 天）進行移植；（B）黃體素補充 &促排卵後第 7 天進行 LPS 注射移植；（C）不黃體素補充&促排卵後第 6 天進進行移植；（D）不黃體素補充 &促排卵後第 7 天進行移植--------- 四組活產率無明顯差異

黃體素補充與否 & 注射促排卵後第 6 天或第7天對活產率無明顯影響

. 2026 Jan 13;2026(1):hoag003.

 doi: 10.1093/hropen/hoag003. eCollection 2026.

Optimizing the protocol for modified natural cycle frozen embryo transfer (mNC-FET): a multicentre, single-blinded randomized controlled trial

Study question: Can the use of progesterone luteal phase support (LPS) and timing of blastocyst transfer, at 6 versus 7 days following hCG-trigger, improve the live birth rate (LBR) in modified natural cycle (mNC) frozen-thawed embryo transfer (FET)?

Summary answer: Use of LPS and advanced timing of blastocyst transfer did not significantly improve the LBR in mNC-FET.

What is known already: Transfer of a frozen-thawed blastocyst in the mNC protocol is routinely conducted 7 days after the ovulation trigger, and progesterone LPS is commonly used despite limited evidence.

Study design size duration: This multicentre, single-blinded, randomized controlled superiority trial investigated the effect of LPS and timing of blastocyst transfer on live birth rates following mNC-FET conducted from January 2019 to February 2024. Using an online randomization programme, patients were randomized 1:1:1:1 to: (A) transfer day 6 following ovulation trigger (Day 0) with LPS; (B) transfer day 7 with LPS; (C) transfer day 6 without LPS; (D) transfer day 7 without LPS. Use of LPS was masked from treating clinicians. The sample size calculation required 604 women to participate to detect an increase in live birth rate from 21% in control groups (LPS: C + D, timing: B + D) to 31% in intervention groups (LPS: A + B, timing: A + C). In total, 679 women were enrolled, and 610 women were randomized. Ultimately, 602 women (A: n = 151; B: n = 150; C: n = 149; D: n = 152) were included in the per-transfer analyses.

Participants/materials setting methods: Participants were women aged 18-41 years undergoing mNC-FET with a single autologous good-quality blastocyst, from eight public fertility clinics at tertiary care centres across Denmark.

Main results and the role of chance: Our study found that use of LPS did not significantly affect the LBR compared with no LPS: 34.9% (105/301) versus 31.9% (96/301) (adjusted risk difference (aRD) 3.18, 95% CI: -4.13 to 10.49; P = 0.39). Comparing blastocyst transfer on Day 6 versus Day 7, there was again no significant difference in LBR: 33.8% (99/300) versus 33.0% (99/302) (aRD -0.62, 95% CI: -7.99 to 6.75; P = 0.87).

• 於 hCG 觸發或 LH 高峰出現後 160 ± 4 小時（相當於排卵後 120 ± 4 小時）進行的胚胎移植---可達到較高的活產率
• 自然組的整體活產率（36.8%；95% CI 33.7-39.9%）低於改良自然組(施打hCG)的活產率（41.3%；95% CI 35.4-47.1%）

. 2022 Nov 24;37(12):2797-2807.

 doi: 10.1093/humrep/deac227.

Is there an optimal window of time for transferring single frozen-thawed euploid blastocysts? A cohort study of 1170 embryo transfers

Study question: Is there an optimal window of time when the transfer of single frozen-thawed euploid blastocysts is associated with a maximal live birth rate (LBR)?

Summary answer: Performing a single frozen-thawed euploid blastocyst transfer at 160 ± 4 h post-hCG trigger in modified-natural frozen-thawed embryo transfer (FET) cycles was independently associated with a higher LBR as compared to transfers outside this window; however, in natural FET cycles, LBRs were comparable across a wider range of time intervals.

What is known already: There is compelling evidence for maintaining embryo-endometrial synchrony to optimize clinical outcomes following FETs, which could potentially be achieved by matching the transfer time of an embryo post-ovulation to its developmental age post-oocyte retrieval. For modified-natural cycles, ovulation is widely accepted to occur ∼40 h following the hCG trigger, whilst ovulation following spontaneous LH surge onset is thought to vary from 24 to 56 h.

Study design, size, duration: This is a multicentered retrospective cohort study analyzing 1170 single frozen-thawed euploid blastocyst transfers following trophectoderm biopsy and preimplantation genetic testing (PGT) between May 2015 and February 2019. Limiting the analysis to single euploid embryo transfers allowed for a more accurate estimation of the endometrial synchrony factor by controlling for the developmental stage of the embryo (full blastocyst or more advanced) and its genetic composition. LBR per FET was the primary outcome measure.

Participants/materials, setting, methods: Patients underwent natural or gonadotrophin-induced preparation of the endometrium, with serial serum oestradiol, LH and progesterone measurements. Optimally timed transfers were predefined as those conducted 120 ± 4 h post-ovulation since biopsy and subsequent cryopreservation of full blastocysts which is usually performed at 116-124 h post-oocyte retrieval. This was considered the equivalent of 160 ± 4 h post-hCG trigger in modified-natural cycles (n = 253), as ovulation was assumed to occur ∼40 h after the hCG trigger. For natural cycles (n = 917), this was also considered to be, on average, 160 ± 4 h post the spontaneous LH surge. Thus, study groups were determined as those with optimal timing or not, and additional exploratory and subgroup analyses were performed, varying the time window in terms of onset and width, both overall and per endometrial preparation protocol. Statistical analysis was performed using the generalized estimating equations (GEE) framework to control for the clustered nature of the data while adjusting for potential confounders.

Main results and the role of chance: Overall, LBRs were significantly higher when the transfer had been performed at 160 ± 4 h post-hCG trigger or LH surge onset compared to when it had been performed outside this window (44.7% vs 36.0%; P = 0.008). A multivariable regression GEE model including the cycle type (natural versus modified-natural), previtrification embryo quality (top versus good quality), embryo stage (fully hatched versus hatching or earlier blastocyst), vitrification day (D5 versus D6) and survival rate (>90% versus <90%) as covariates, confirmed that, overall, embryo transfers conducted 160 ± 4 h post-hCG trigger or LH surge onset (the assumed equivalent of 120 ± 4 h post-ovulation) were associated with a significantly higher LBR (relative risk (RR) 1.21, 95% CI 1.04-1.41). Subgroup exploratory analyses per endometrial preparation protocol demonstrated that these findings were primarily present in the modified-natural cycle group (RR 1.52, 95% CI 1.15-1.99), whilst the natural cycle group showed comparable LBRs across a wider range of time intervals. Moreover, the overall LBR for the natural group (36.8%; 95% CI 33.7-39.9%) was lower than that of the modified-natural group (41.3%; 95% CI 35.4-47.1%), suggesting that there likely remains a greater potential to further optimize the timing of natural cycle embryo transfers.

密度梯度離心 (DGC)  vs DGC 後進行磁活化細胞分選 (MACS) vs 使用精子分離裝置 (SSD)

傳統 DGC 相比，MACS 和 SSD 後的 DFI (DNA fragmentation index)

均顯著降低

SSD 和 MACS 之間的進一步比較表明，SSD 組中凋亡細胞明顯較少。

Observational Study

 

. 2024 Aug;41(8):2201-2209.

 doi: 10.1007/s10815-024-03168-9. Epub 2024 Jun 18.

Optimized sperm selection: a highly efficient device for the isolation of progressive motile sperm with low DNA fragmentation index

Purpose: To identify the sperm preparation procedure that selects the best sperm population for medically assisted reproduction.

Methods: Prospective observational study comparing the effect of four different sperm selection procedures on various semen parameters. Unused raw semen after routine diagnostic analysis was split in four fractions and processed by four different methods: (1) density gradient centrifugation (DGC), (2) sperm wash (SW), (3) DGC followed by magnetic activated cell sorting (MACS), and (4) using a sperm separation device (SSD). Each fraction was analyzed for progressive motility, morphology, acrosome index (AI), and DNA fragmentation index (DFI).

Results: With DGC as standard of care in intraclass correlation coefficient analysis, only SSD was in strong disagreement regarding progressive motility and DFI [0.26, 95%CI (- 0.2, 0.58), and 0.17, 95%CI (- 0.19, 0.45), respectively]. When controlling for abstinence duration, DFI was significantly lower after both MACS and SSD compared to DGC [- 0.27%, 95%CI (- 0.47, - 0.06), p = 0.01, and - 0.6%, 95%CI (- 0.80, - 0.41), p < 0.001, respectively]. Further comparisons between SSD and MACS indicate significantly less apoptotic cells [Median (IQR) 4 (5), 95%CI (4.1, - 6.8) vs Median (IQR) 5 (8), 95%CI (4.9, - 9.2), p < 0.001, respectively] and dead cells [Median (IQR) 9.5 (23.3), 95%CI (13.2, - 22.4) vs Median (IQR) 22 (28), 95%CI (23.1, - 36.8), p < 0.001, respectively] in the SSD group.

Conclusion: The selection of a population of highly motile spermatozoa with less damaged DNA from unprocessed semen is ideally performed with SSD. Question remains whether this method improves the embryological outcomes in the IVF laboratory.

接受微流控精子製備的患者與接受標準精子處理進行體外受精 (IVF) 和卵胞漿內單精子注射 (ICSI) 的患者相比，其卵裂期和囊胚期胚胎質量以及臨床妊娠率和持續妊娠率相似。

Randomized Controlled Trial

 

. 2022 Jun 30;37(7):1406-1413.

 doi: 10.1093/humrep/deac099.

Microfluidic preparation of spermatozoa for ICSI produces similar embryo quality to density-gradient centrifugation: a pragmatic, randomized controlled trial

Study question: Does processing of spermatozoa for IVF with ICSI by a microfluidic sperm separation device improve embryo quality compared with density-gradient centrifugation?

Summary answer: Patients randomized to microfluidic sperm preparation had similar cleavage- and blastocyst-stage embryo quality and clinical and ongoing pregnancy rates to those who underwent standard sperm processing for IVF with ICSI.

What is known already: Microfluidic sperm preparation can isolate spermatozoa for clinical use with minimal DNA fragmentation but with unclear impact on clinical outcomes.

Study design, size, duration: A prospective randomized controlled trial of 386 patients planning IVF from June 2017 through September 2021 was carried out.

Participants/materials, setting, methods: One hundred and ninety-two patients were allocated to sperm processing with a microfluidic sperm separation device for ICSI, while 194 patients were allocated to clinical standard density-gradient centrifugation (control) at an academic medical centre.

Main results and the role of chance: In an intention to treat analysis, there were no differences in high-quality cleavage-stage embryo fraction [66.0 (25.8)% control versus 68.0 (30.3) microfluidic sperm preparation, P = 0.541, absolute difference -2.0, 95% CI (-8.5, 4.5)], or high-quality blastocyst fraction [37.4 (25.4) control versus 37.4 (26.2) microfluidic sperm preparation, P = 0.985, absolute difference -0.6 95% CI (-6, 5.9)] between groups. There were no differences in the clinical pregnancy or ongoing pregnancy rates between groups.

吸菸、高齡和環境污染物  環境因會影響精子DNA甲基化組。

男性生育力低下和精液參數異常，尤其是少精子症，似乎與精子DNA甲基化異常有關。

目前尚無確鑿證據顯示精子DNA甲基化的變化會影響懷孕後代健康。

. 2020 Nov 1;26(6):841-873.

 doi: 10.1093/humupd/dmaa025.

DNA methylation in human sperm: a systematic review

Background: Studies in non-human mammals suggest that environmental factors can influence spermatozoal DNA methylation, and some research suggests that spermatozoal DNA methylation is also implicated in conditions such as subfertility and imprinting disorders in the offspring. Together with an increased availability of cost-effective methods of interrogating DNA methylation, this premise has led to an increasing number of studies investigating the DNA methylation landscape of human spermatozoa. However, how the human spermatozoal DNA methylome is influenced by environmental factors is still unclear, as is the role of human spermatozoal DNA methylation in subfertility and in influencing offspring health.

Objective and rationale: The aim of this systematic review was to critically appraise the quality of the current body of literature on DNA methylation in human spermatozoa, summarize current knowledge and generate recommendations for future research.

Search methods: A comprehensive literature search of the PubMed, Web of Science and Cochrane Library databases was conducted using the search terms 'semen' OR 'sperm' AND 'DNA methylation'. Publications from 1 January 2003 to 2 March 2020 that studied human sperm and were written in English were included. Studies that used sperm DNA methylation to develop methodologies or forensically identify semen were excluded, as were reviews, commentaries, meta-analyses or editorial texts. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria were used to objectively evaluate quality of evidence in each included publication.

Outcomes: The search identified 446 records, of which 135 were included in the systematic review. These 135 studies were divided into three groups according to area of research; 56 studies investigated the influence of spermatozoal DNA methylation on male fertility and abnormal semen parameters, 20 studies investigated spermatozoal DNA methylation in pregnancy outcomes including offspring health and 59 studies assessed the influence of environmental factors on spermatozoal DNA methylation. Findings from studies that scored as 'high' and 'moderate' quality of evidence according to GRADE criteria were summarized. We found that male subfertility and abnormal semen parameters, in particular oligozoospermia, appear to be associated with abnormal spermatozoal DNA methylation of imprinted regions. However, no specific DNA methylation signature of either subfertility or abnormal semen parameters has been convincingly replicated in genome-scale, unbiased analyses. Furthermore, although findings require independent replication, current evidence suggests that the spermatozoal DNA methylome is influenced by cigarette smoking, advanced age and environmental pollutants. Importantly however, from a clinical point of view, there is no convincing evidence that changes in spermatozoal DNA methylation influence pregnancy outcomes or offspring health.

 嚴重少精症會造成ICSI後

受孕率下降

延長胚胎第2次分裂時間

D3胚胎品質

The effect of severe oligozoospermia on embryo dynamics and morphological quality

Purpose

This study evaluated whether severe oligozoospermia affects early cleavage-stage dynamics and blastocyst developmental competence in ICSI cycles cultured in a time-lapse system.

Methods

This retrospective matched cohort study included ICSI cycles using fresh ejaculated sperm and fresh autologous oocytes at Assisted Reproductive Center, Tam Anh Hanoi General Hospital (February 2022–December 2024). Initially, eligible cycles were identified in both groups. After propensity score matching (1:2), the final analytic cohort comprised 39 cycles in the severe oligozoospermia group and 78 cycles in the normozoospermia group. All normally fertilized zygotes (2PN) were monitored up to day 7. Cleavage-stage morphokinetic parameters and abnormal cleavage patterns were analyzed. Multivariate analyses evaluated overall morphokinetic differences. A generalized linear mixed model (GLMM) tested predictors of usable blastocysts, comparing 4095 candidate models based on the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC).

Results

A total of 117 ICSI cycles were analyzed after propensity score matching, including 39 cycles with severe oligozoospermia and 78 normozoospermic controls. Despite a significantly higher number of retrieved MII oocytes, the severe oligozoospermia group exhibited lower fertilization rates (71.33% vs. 77.98%, p = 0.012) and a reduced proportion of top-quality day-3 embryos (51.25% vs. 65.82%, p < 0.001). Blastocyst formation and top-quality blastocyst rates did not differ significantly between groups. Cleavage-stage morphokinetic analysis revealed a statistically significant prolongation of the second cell cycle (ECC2) in the severe oligozoospermia group; however, the absolute difference was small (~ 0.25 h) and accounted for a limited proportion of variance (R² ≈ 1.4%). No significant differences were observed in subsequent morphokinetic parameters, including ECC3 or the synchrony parameters s2 and s3. In generalized linear mixed-model analysis using embryo usability (transfer or cryopreservation) as a laboratory-defined surrogate outcome, sperm concentration was not identified as an independent predictor.

Conclusions

Severe oligozoospermia was associated with impaired fertilization outcomes and reduced day-3 embryo quality. A modest but statistically significant prolongation of ECC2 was observed; however, when sperm concentration was evaluated in isolation under ICSI conditions, later cleavage-stage morphokinetics and blastocyst development appeared largely preserved at the laboratory level. These findings are limited to sperm concentration alone and may be influenced by unmeasured sperm functional defects.

 10種以上gene  影響精蟲頸部的蛋白質 中心粒及胞器  其基因突變會造成精蟲斷頭現象(從精蟲頸部斷裂)

Review

 

. 2026 Feb;43(2):347-365.

 doi: 10.1007/s10815-025-03769-y. Epub 2026 Jan 5.

The spermatozoon neck role in infertility and intracytoplasmic sperm injection outcomes

The mammalian spermatozoon neck is a unique structure that functions during spermatid differentiation and spermatozoa swimming, and its contents are critical for post-fertilization embryogenesis. Mutations in proteins localizing to the neck connecting piece (the modified pericentriolar material) result in acephalic spermatozoa. In contrast, mutations in proteins localizing to the centriole often produce abnormal tail morphology. Acephalic spermatozoa can be categorized based on the exact location of the neck breakpoint. Here, we classify 24 proteins known to cause acephaly in human and mice spermatozoa into five different acephalic types, depending on where the breakpoint occurs. We also discuss other proteins found in the spermatozoon neck, which may result in spermatozoa acephaly. The relationship between the exact location of the neck's break and intracytoplasmic sperm injection (ICSI) outcomes is explored in the context of the spermatozoon centrosome's role. We conclude that to understand this relationship, future research should investigate DNA, phospholipase C zeta, and centriole functionality, in addition to the location of the acephalic breakpoint in the patient's sperm.