Long-time vs. short-time insemination of sibling eggs

The utility of human two plus one small pronucleated zygotes (2.1PN) based on clinical outcomes and the focused ploidy analysis

PURPOSE

Are human embryos arising from two plus one small pronucleated zygotes, called 2.1 pronuclei (PN), clinically useful?

METHODS

In a retrospective embryo cohort study and prospective experimental study, a total of 287 cycles in which at least one 2.1PN was identified in the fertilization check were included. Embryonic development and clinical outcome were compared for the 1395 2PN zygotes and 304 2.1PN zygotes that were siblings. All embryos were individually cultured in time-lapse systems. Twenty-five 2.1PN-derived blastocysts, donated for research, were used in focused single-nucleotide variant ploidy analysis to identify the distribution pattern of heterozygosity.

RESULTS

The average diameter of PN was 24.9 ± 2.4 µm for large PN and 10.2 ± 2.4 µm for small PN; 79.9% of small PN was derived from female pronuclei. Blastocyst formation rate and good-quality blastocyst rate were significantly lower with 2.1PN embryos than with 2PN embryos (40.0% vs. 57.7%, 21.4% vs. 33.5%, respectively). A total of 13 embryos derived from 2.1PN were transferred, and three healthy babies were born. In ploidy constitutions of trophectoderm (TE), 2.1PN-derived blastocyst TE was shown to be mostly diploid (95.8%, 23/24), and only one blastocyst showed triploid.

CONCLUSIONS

It was suggested that 2.1PN embryos have lower embryonic developmental potential than 2PN embryos, but most of the 2.1PN were diploid, indicating that they are likely to be clinically usable. It is recommended to perform embryo transfer following a combination of PGT-A and ploidy analysis.

Effect of cytoplasmic fragmentation on embryo development, quality, and pregnancy outcome: a systematic review of the literature

The role of cytoplasmic fragmentation in human embryo development and reproductive potential is widely recognized, albeit without standard definition nor agreed upon implication. While fragmentation is best understood to be a natural process across species, the origin of fragmentation remains incompletely understood and likely multifactorial. Several factors including embryo culture condition, gamete quality, aneuploidy, and abnormal cytokinesis seem to have important role in the etiology of cytoplasmic fragmentation. Fragmentation reduces the volume of cytoplasm and depletes embryo of essential organelles and regulatory proteins, compromising the developmental potential of the embryo. While it has been shown that degree of fragmentation and embryo implantation potential are inversely proportional, the degree, pattern, and distribution of fragmentation as it relates to pregnancy outcome is debated in the literature. This review highlights some of the challenges in analysis of fragmentation, while revealing trends in our evolving knowledge of how fragmentation may relate to functional development of the human embryos, implantation, and pregnancy outcome.

Early cumulus cell removal increases cumulative live birth rate while having no negative effect on the malformation rate in in vitro fertilization: a propensity score-matched cohort study

PURPOSE

The aim of this study was to investigate the efficacy and safety of early cumulus cell removal (ECCR) during human in vitro fertilization (IVF).

METHODS

A retrospective analysis was performed between January 2011 and December 2019. The study enrolled 1131 couples who underwent IVF treatment with ECCR. After propensity score matching at a 1:1 ratio, 1131 couples who underwent overnight coincubation of gametes were selected. The main outcome measure was the cumulative live birth rate. Secondary outcome measures included the cumulative pregnancy rate, polyspermy rate, available embryo rate, miscarriage rate, malformation rate, time to live birth, and oocyte-to-baby rate.

RESULTS

There were no significant differences found between the two groups in the polyspermy rate, available embryo rate, miscarriage rate, time to live birth, oocyte-to-baby rate, and neonatal congenital anomalies rate. The results of the study showed that ECCR was associated with a significantly higher cumulative live birth rate and cumulative pregnancy rate, along with a significantly lower fertilization rate.

CONCLUSIONS

ECCR tended to confer increased cumulative live birth rate and had no negative effect on the neonatal malformation rate.

Comparing the pregnancy outcomes of Re‑ICSI and ICSI embryos in fresh ET and FET cycles

Early rescue intracytoplasmic sperm injection (Re-ICSI) can prevent total fertilization failure (TFF) during conventional in vitro fertilization (IVF). However, the implantation rate of Re-ICSI embryos is lower than that of direct ICSI during fresh embryo transfer (ET). The aim of the present study was to investigate the effect of frozen ET (FET) after Re-ICSI. In the present retrospective study, primary infertility patients that underwent the first Re-ICSI and ICSI treatment, were studied. The clinical pregnancy rate, implantation rate, ectopic pregnancy, abortion rate and live birth rate were analyzed between the Re-ICSI and ICSI groups in fresh ET and FET cycles. The average age of patients between Re-ICSI and ICSI groups in fresh ET and FET cycles was (29.0±3.2 vs. 29.1±3.1, and 29.1±3.3 vs. 28.9±3.0), respectively (P>0.05). Compared with ICSI embryos, the clinical pregnancy, implantation and live birth rates of Re-ICSI embryos were lower in fresh ET cycles. By contrast, there were no significant differences in the pregnancy, implantation and live birth rates between the Re-ICSI and ICSI embryos during the FET cycles. Re-ICSI coupled with FET may overcome the impaired outcomes in fresh ET.

Fertilization and neonatal outcomes after early rescue intracytoplasmic sperm injection: a retrospective analysis of 16,769 patients

Purpose

To evaluate the efficacy and safety of short-term insemination and early-rescue intracytoplasmic sperm injection (ICSI), an approach that rescued oocytes with unclear second polar body 6 h after initial insemination by ICSI (early R-ICSI) to avoid total or near-total fertilization failure in conventional in vitro fertilization (IVF).

Methods

We performed a retrospective study in 16,769 patients (short-term IVF, n = 12,094; ICSI, n = 3452; early R-ICSI, n = 1223) who received IVF/ICSI treatment in our hospital from January 2009 to October 2018. Fertilization and clinical outcomes were compared among those three groups.

Results

When considering the R-ICSI embryos in the early R-ICSI group independently, the rates of fertilization and day-3 cleaved embryos in 2PN oocytes were comparable, the rates of fertilization (2PN) and high-quality embryos were lower, whereas the multi-PN fertilization rate (3.27%) was significantly higher than the ICSI group (1.26%). The difference of clinical pregnancy rate between the part of transferred R-ICSI embryos (40.81%) and the ICSI group (44.73%) remained nonsignificant. Furthermore, the rate of congenital birth defects in the early R-ICSI group (0.99%) was not significantly different from those in the short-term IVF (0.76%) and ICSI groups (1.07%).

Conclusion

Despite the multi-PN fertilization rate, our study highlights early R-ICSI as a safe and effective alternative in assisted reproduction to decrease complete IVF fertilization failure and reduce ICSI utilization. Additional large amount and long-term follow-up studies are needed to further validate the use of early R-ICSI.

Effect of melatonin on the clinical outcome of patients with repeated cycles after failed cycles of in vitro fertilization and intracytoplasmic sperm injection

To explore whether embryo culture with melatonin (MT) can improve the embryonic development and clinical outcome of patients with repeated cycles after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) failure, immature oocytes from controlled ovarian superovulation cycles were collected for in vitro maturation (IVM) and ICSI. The obtained embryos were cultured in 0, 10–11, 10–9, 10–7 and 10–5 M MT medium respectively, and 10–9 M was screened out as the optimal concentration. Subsequently, 140 patients who underwent failed IVF/ICSI cycles received 140 cycles of embryo culture in vitro with a medium containing 10–9 M MT, these 140 MT culture cycles were designated as the experimental group (10–9 M group), and the control group was the previous failed cycles of patients (0 M group). The results showed that the fertilization, cleavage, high-quality embryo, blastocyst, and high-quality blastocyst rates of the 10–9 M group were significantly higher than those of the 0 M group (P < 0.01; P < 0.01; P < 0.0001; P < 0.0001; P < 0.0001). To date, in total, 50 vitrified-warmed cycle transfers have been performed in the 10–9 M group and the implantation rate, biochemical pregnancy rate and clinical pregnancy rate were significantly higher than those in the 0 M group (all P < 0.0001). Two healthy infants were delivered successfully and the other 18 women who achieved clinical pregnancy also had good examination indexes. Therefore the application of 10–9 M MT to embryo cultures in vitro improved embryonic development in patients with repeated cycles after failed IVF/ICSI cycles and had good clinical outcomes.

Trial registration: ChiCTR2100045552.

Effect of early rescue ICSI and split IVF-ICSI in preventing low fertilization rate during the first ART cycle: A real-world retrospective cohort study

Purpose

To determine the utility of short gamete coincubation in in vitro fertilization (IVF‐S) combined with early rescue intracytoplasmic sperm injection (R‐ICSI) and split IVF‐ICSI in preventing low fertilization based on a retrospective cohort study.

Methods

Couples with a high risk of low IVF fertilization during the first ART cycle underwent IVF‐S with R‐ICSI or split IVF‐ICSI. Fertilization rate, embryo quality, and clinical outcomes were measured.

Results

After propensity score matching, we included 188 couples in the IVF‐S with R‐ICSI group as Group 1 and 720 in the split IVF‐ICSI group as Group 2. Normal fertilization rates were similar; however, Group 1 had a higher multiple pronuclei rate (10.42% vs. 4.50%, p < 0.001) but a higher embryo utilization rate (59.84% vs. 53.60%, p < 0.001). The groups were similar in the rates of high‐quality embryos, embryo implantation, clinical pregnancy, and live birth. Low IVF fertilization rate was 4.79% and 9.03% in Group 1 and Group 2, respectively, with similar fertilization rate and embryo development.

Conclusion

IVF‐S with early R‐ICSI and split IVF‐ICSI were effective strategies in preventing low fertilization rate. IVF‐S with early R‐ICSI could become the preferred approach because of its advantages—higher embryo utilization rate, fewer ICSI procedures, similar clinical pregnancy rate, and live birth rate.

Comparison of embryonic competence and clinical outcomes between early and late cumulus cell removal for in vitro fertilization

Objective

The impact of early mechanical removal of cumulus cells on fertilization and embryonic development is not yet precisely known. This study aimed to investigate the effects of early and late cumulus cell removal on fertilization, polyspermy, embryonic development potential, blastocyst development, and clinical outcomes.

Methods

A prospective study was conducted of patients who underwent in vitro fertilization between September 2019 and October 2020. Sibling oocytes were randomly allocated after insemination to early cumulus cell removal at 6 hours (group I) and late cumulus cell removal at 16–18 hours (group II). If total fertilization failure (TFF) was determined to have occurred at early cumulus cell removal, rescue intracytoplasmic sperm injection (ICSI) was performed. Fertilization, embryonic development, and pregnancy outcomes were compared.

Results

A total of 912 oocytes were assigned to group I (458 oocytes) and group II (454 oocytes). Fertilization, polyspermy, embryo quality, and pregnancy outcomes were not significantly different between both groups. Rescue ICSI enabled fertilization of 79.2% of the TFF oocytes.

Conclusion

Early cumulus cell removal at 6 hours had no significant difference in fertilization, polyspermy, embryo development, or obstetric and perinatal outcomes compared to late removal. Early cumulus cell removal combined with early rescue ICSI may have the potential to help couples with TFF.

Associations between ambient air pollution and IVF outcomes in a heavily polluted city in China

RESEARCH QUESTION

Is air pollution related to IVF outcomes in a heavily polluted city in China?

DESIGN

A retrospective cohort study of 8628 fresh, autologous IVF cycles was conducted for the first time at the Reproductive Medicine Center of The Third Affiliated Hospital of Zhengzhou University between May 2014 and December 2018 (oocyte retrieval date). The exposure was divided into four periods (gonadotrophin injection to oocyte retrieval [P1], oocyte retrieval to embryo transfer [P2], 1 day after embryo transfer to embryo transfer +14 days [P3] and gonadotrophin injection to embryo transfer +14 days [P4]) and four levels (Q1-Q4 according to their 25th, 50th and 75th percentiles).

RESULTS

An interquartile range increase (Q2 versus Q1) in particulate matter ≤10 µm (PM10) during P3 and P4 and sulphur dioxide (SO₂) during P3 significantly decreased the clinical pregnancy rate (adjusted odds ratio [aOR] 0.81, 95% confidence interval [CI] 0.71-0.92 for PM10 of P3; aOR 0.87, 95% CI 0.76-1.00 for PM10 of P4; aOR 0.82, 95% CI 0.73-0.93 for SO₂ of P3). In addition, PM10 was associated with an increased biochemical pregnancy rate (Q3 versus Q1: aOR 1.55, 95% CI 1.09-2.19 for PM10 of P1) and decreased live birth rate (Q2 versus Q1: aOR 0.88, 95% CI 0.77-0.99 for PM10 of P3). The multivariate regression results were consistent with that of multiple treatments propensity score method (PSM) for SO₂ pollutants in P3 and PM10 pollutants in P4.

CONCLUSION

From the early follicular stage to the pregnancy test period, high concentrations of PM10 and SO₂ may have a negative impact on IVF treatment outcomes in the study area.

A comparison of the clinical effects of thinning and drilling on laser-assisted hatching

To systematically investigate the effects of two methods used for laser-assisted hatching (LAH) on clinical outcomes after day 4 (D4) on frozen-embryo-transfer (FET) cycles. Data from 11471 infertile patients who underwent FET cycles between January 2014 and October 2018 was retrospectively analyzed. The 1410 patients who met the inclusion criteria were further categorized into two groups based on the hatching procedure used: the thinning laser-assisted hatching group (T-LAH, 716 patients), and the drilling laser-assisted hatching group (D-LAH, 694 patients). The baseline characteristics of the patients were consistent between the two groups. However, the rates of implantation and clinical pregnancy were significantly higher in the T-LAH group compared to the D-LAH group (32.73% vs. 29.09%, P < 0.01, and 50.98% vs. 43.95%, P < 0.01). The proportion of live birth was also higher in the T-LAH group, but the difference was insignificant (39.11% vs. 36.89%, P > 0.05). Moreover, there were no significant differences in rates of miscarriages, multiple pregnancies, ectopic pregnancies, preterm births, and congenital disabilities between the two groups. Nonetheless, significantly higher rates of implantation and pregnancy were reported in the T-LAH group compared to the D-LAH group among patients aged <35 years, patients with at least one previously failed cycle, and patients with an endometrial thickness of 8-10 mm. T-LAH is superior to D-LAH in improving clinical implantation and pregnancy outcomes in D4 FET, particularly in patients aged <35 years with at least one previously failed cycle or an endometrial thickness of 8-10 mm. The findings of this study provide theoretical support for clinical individualized diagnosis and treatment of patients with infertility.

Does sperm DNA fragmentation have negative impact on embryo morphology and morphokinetics in IVF programme?

Evaluation of sperm integrity may predict the in vitro fertilisation (IVF) outcomes. The aim was to evaluate the relationship between the sperm DNA fragmentation (sDNAf) with embryo morphology and morphokinetic using time-laps monitoring (TLM) and to select the best time points for normalisation in IVF setting. After evaluating the fertilisation and pronuclei (Z) scoring, 328 normally fertilised oocytes were assessed to time of pronuclei fading, time of 2 to 8 discrete cells (t2-t8) and abnormal cleavage patterns, such as multinucleation, direct cleavage, reverse cleavage and fragmentation. Sperm chromatin dispersion (SCD) assay was used for assessment of prepared sperm chromatin status. SCD was categorised into 4 groups of <6.5, 6.5-10.7, 10.7-20.1 and >20.1. The finding showed significant differences in t6 (p = .012), t7 (p = .045), t8 (p = .013) and s1 (p = .001) between 4 SCD groups. When morphokinetic variables were normalised to tPNf, this difference was observed in t2 (p = .003) and t6 (p = .017). Subsequently, the percentage of top quality embryos and Z₁ scoring were dependent to the sDNAf rate. In conclusion, tPNf was the best reference time point in IVF cycles. Also, we found high sDNAf rate had no negative impact on embryo morphology and morphokinetics in conventional IVF.

Effect of early cumulus cells removal and early rescue ICSI on pregnancy outcomes in high-risk patients of fertilization failure

OBJECTIVE

The objective of this retrospective study was to evaluate clinical outcomes of early cumulus cells removal and early rescue intracytoplasmic sperm injection (ICSI) in high-risk patients of fertilization failure during human in vitro fertilization (IVF).

METHODS

A total of 5,518 patients were enrolled between January 2014 to December 2016. Of which 505 couples performed short insemination with >30% fertilization rate were included in short-term IVF group, 102 patients detected total fertilization failure (TFF) were treated with early rescue ICSI (R-ICSI group), and 4911 couples underwent conventional IVF with overnight co-incubation of gametes (traditional IVF group). The clinical outcomes were analyzed among the three groups.

RESULTS

The embryo implantation rates (40.34%, 39.78% and 42.42% for traditional, short-term IVF and R-ICSI groups, respectively) were comparable in the three groups. The clinical pregnancy rates among traditional IVF group, short-term IVF group and R-ICSI group were 57.95%, 57.03% and 60.78%, respectively, and the difference among three groups didn't reach significance.

CONCLUSION

The present study indicated that short insemination had no detrimental effects on clinical outcomes in human IVF and could prevent the occurrence of TFF combined with early rescue ICSI for high-risk patients of fertilization failure, which attained acceptable pregnancy outcomes.