Laser-assisted Hatching Group Research Articles

P-193 Does the day of laser-assisted hatching affects the clinical outcomes of single vitrified blastocyst transfer cycles? A propensity score–matched study

Abstract Study question What is the impact of different days of laser-assisted hatching on the clinical outcomes of single vitrified blastocyst transfer cycles? Summary answer Clinical pregnancy of single vitrified blastocyst were similar, irrespective of day of laser-assisted hatching. What is known already Assisted hatching aims to create a weakness in the ZP to aid embryo hatching and implantation. Day 5 assisted hatching is typically performed shortly before the embryo transfer while day 3 assisted hatching is performed before blastocyst culture expansion and vitrification. Despite over 25 years of use, there is still no standardized protocol for AH, and published data on its efficacy are controversial and inconclusive. While efforts have been made to study the link between AH techniques and pregnancy outcomes, there is limited consensus for optimizing AH protocols like the day of performance. Study design, size, duration This was a retrospective study based on data collected between January 2022 and October 2023. Propensity score matching (PSM) was performed in a 1:1 matching ratio. 123 patients of day 3 laser assisted hatching group (D3 LAH group) were successfully matched to 123 cycles of day 5 laser assisted hatching group (D5 LAH group). The D5 LAH group was from March 2023 to October 2023, and the D3 LAH from January 2022 to February 2023. Participants/materials, setting, methods Single vitrified day 5 embryo transfer, embryos survived after warming, and patient agreed to receive LAH were include in this study. We excluded donation cycles, missing data, severe female factors. Primary outcome is clinical pregnancy. Comparisons between groups were performed with chi-square test, Fisher’s exact test, Mann–Whitney U test, and Student’s t-test where appropriate, with a P value <0.05 considered statistically significant. A multivariable analysis in the GEE model was adjusted for the confounding factors. Main results and the role of chance After propensity score matching, there was no significant difference in patient characteristics between the groups, creating similar cohorts. For example, the frequency of primary infertility was significantly different between groups initially (61% vs 46.7% in D5 LAH vs D3 LAH respectively, P = 0.004). Following propensity score matching the rate of primary infertility was similar in both groups (with SMD=0.08). Standardized mean difference (SMD) < 0.1 suggests adequate variable balance after propensity matching. Clinical pregnancy rate were similar between two groups: 66/123 (53.7%) D3 LAH cycles and 75/123 (61%) D5 LAH cycles. When generalized estimating equation were performed: only TE grade, but not the day of laser assisted hatching, was noted to be an independent predictor of clinical pregnancy (OR = 0.068; 95% CI: 0.005-0.977; p = 0.048). Poor TE grade had a weak negative relationship with clinical pregnancy of single blastocyst cycles. Limitations, reasons for caution The main limitation of the study is its retrospective design and small sample size. Wider implications of the findings Clinical outcomes are comparable between day 3 laser assisted hatching and day 5 laser assisted hatching, although clinical pregnancy can be slightly improved with higher TE grade. Trial registration number not applicable

THE EFFECT OF LASER-ASSISTED HATCHING ON PREGNANCY OUTCOMES OF VITRIFICATION FROZEN EMBRYO TRANSFER

Highlights LAH might effectively increase pregnancy outcomes for frozen-thawed embryo transfer. Zona pellucida drilling might help increase pregnancy outcomes in FET. Abstract Background: Zona Pellucida (ZP) thickness of less than 16 mm is better for embryo implantation inside the endometrium. Laser Assisted Hatching (LAH) is commonly used, especially in non-contact mode, using a 1.48-um infrared diode laser beam because of its short exposure time, accurate positioning, simple operation, indirect contact, safety, and effectiveness. Objective: This paper describes the potential of laser-assisted hatching in biochemical pregnancy outcomes in Frozen Embryo Thawed transfers. Material and Method: The total number of patients enrolled in this study was 141. Patients were prospectively treated during embryo transfers at Pusat Fertilitas Bocah Indonesia, Primaya Hospital at Tangerang, Indonesia, from December 2020 until December 2021. Result: There were no significant differences between the LAH and no-LAH groups regarding average age, infertility duration, infertility type, and etiology of infertility (p>0.05). In the same line, the blastocyst (0.76 ± 0.87; 1.25 ± 1.08) compared with cleavage (0.72 ± 0.84; 0.67 ± 0.98) (p<0.534 and p< .032). There was no significant difference, even though clinically, the proportions of live births, multiple pregnancies, biochemical pregnancies, and ongoing pregnancies in the LAH group were not exceptions to the outcomes of failures and miscarriages. Conclusion: LAH did not appear to increase the pregnancy rate in this study. However, the methodology seems to reduce bias in this study by considering methodology for selecting FET embryos based on the cryopreserved condition, embryo quality, and precise LAH.

Clinical and neonatal outcomes of complete zona pellucida removal by laser-assisted hatching after single vitrified-warmed blastocyst transfer.

Laser-assisted hatching (LAH) is a widely used and unavoidable technique in assisted reproductive technology after frozen embryo transfer (FET). We aimed to investigate the safety and efficacy of completely ZP (zona pellucida) removed by an assisted laser group compared to an intact group after FET. This retrospective study involved 320 SVBT single vitrified-warmed blastocyst transfers of 213 patients who underwent clomiphene citrate (CC) based minimal stimulation protocol. This study compared 160 SVBT with ZP that were completely removed using laser-assisted (laser beams of 10-15, a wavelength of 1.48μm, and duration of 1.8-2.2ms) to 160 cases of intact SVBT. Fisher's exact test, chi-squared test, and logistic regression are used for statistical analysis. The women's age, cause of infertility, BMI, transferred embryo day, insemination methods, and blastocyst grade were not significantly different between two groups. The implantation rate (66.2% vs. 51.2%, P < 0.01), the clinical pregnancy rate (CPR, 52.5% vs. 39.3%, P = 0.01), and the live birth rate (LBR, 43.7% vs. 29.3%, P < 0.01) were significantly higher in the completely ZP removed than the intact group. In logistic regression analysis, the laser-assisted hatching group showed about 2 times higher implantation rate and CPR and LBR than the control group. But miscarriage, gestational weeks, gender, birth weight, and twin births were insignificant between two groups. Our study suggests ZP free embryo transfer by assisted laser is more effective and safer than intact embryo transfer.

P-286 Can laser assisted hatching help implantation of warmed blastocysts in presence of fragmented cells ?

Abstract Study question Does laser assisted hatching (LAH) following warming of blastocysts containing fragmentated cells improves blastocyst expansion and implantation? Summary answer The application of LAH does not improve blastocyst expansion and implantation regardless the presence or absence of fragmented cells. What is known already The absence of natural hatching is one of the hypotheses of implantation failure after cryopreservation, a process that could lead to hardening of the zona pellucida. Another theory is the fact that cellular fragments inside the zona pellucida, surrounding the trophectoderm, could impairs the exit of the blastocyst through the zona decreasing its chances of implantation. Available data regarding the effect of LAH on blastocysts after vitrification are inconclusive and limited to small samples. Evaluating the effectiveness of LHA performed at the time of blastocyst warming when cellular fragments are present could elucidate its impact on hatching and implantation Study design, size, duration A bicentric prospective randomized study including 344 successive FET cycles from January 2020 until March 2021. Patients were enrolled only once in the study. Patients underwent a natural cycle or hormonal replacement treatment for FET. Blastocysts graded ≥ BL3BB (Gardner scoring) underwent artificial collapse and were vitrified on D5 or D6. Only blastocysts surviving post-warming were considered in the analysis. Primary end point was clinical pregnancy rate. Participants/materials, setting, methods Patients ≤42 years with ≤3 previous oocyte retrievals scheduled for the first elective single embryo transfer (eSET) with vitrified/warmed blastocysts. Survived blastocysts were randomized immediately after warming to LAH group (n = 172) or to control group (no-LAH, n = 172). Cellular fragmentation was annotated as a percentage of the total volume of the embryo (0%, ≤25%, ≤50%, &amp;gt;50%) and LHA was performed on the opposite side. Embryo expansion was annotated at time of transfer, at 3 hours post-warming. Main results and the role of chance Patients age were similar between LHA (33.1±9.3) and controls (34.8±7.5). Patients in LAH and controls had similar pregnancy rates (hCG &amp;gt;100) (46% versus 52%, respectively), CPR (37% versus 36%, respectively) (NS) and miscarriage rates. No difference was observed in CPR in relation to patients age. A significant increase in implantation was observed when blastocyst expansion took place 3 hours after warming, independently whether allocated in LAH (47% versus 17%, p &amp;lt; 0.01) or no-LAH group (51% versus 33%, p &amp;lt; 0.01). LAH did not influence cell expansion (83% in LAH versus 85% in no-LAH), however more blastocysts underwent hatching in LAH group (27% versus 12% in no-LAH, p &amp;lt; 0.06). Significantly more embryos that had hatched in LAH group led to pregnancy compared to no-LHA (83% versus 67%, respectively) (p = 0.05). Extra-cellular (EC) fragmentation not did not impact implantation in neither of the groups. LAH group had 46% of embryos implanted when absence of fragmentation, 40% when EC was present at ≤ 25%, 58% when EC was present at &amp;gt; 25% (NS). In no-LAH group, 52% of embryos implanted when absence of fragmentation, 49% when EC was present at ≤ 25%, 65% when EC was present at &amp;gt; 25% (NS). Limitations, reasons for caution A sample size of 700 blastocysts was first chosen calculating a 10% difference in clinical pregnancy rate (CPR) between LAH-group and no-LAH group. The study was interrupted following this interim analysis. Live birth outcomes should be considered in a further analysis to conclude on the null impact of LHA post-warming. Wider implications of the findings This study adds to the evidence of the existence of a limited potential of the application of LAH on vitrified-warmed blastocysts and its impact in terms of clinical pregnancy rates. Trial registration number not applicable

Laser-assisted hatching on clinical and neonatal outcomes in patients undergoing single vitrified Blastocyst transfer: A propensity score-matched study.

PurposeThis study determined the effect of laser‐assisted hatching on the clinical and neonatal outcomes of single vitrified blastocyst transfer.MethodsFrom June 2014 to March 2018, 289 matched pairs after propensity score matching were analyzed. During the blastocyst warming procedure, a small section of the zona pellucida area in the empty perivitelline space was sliced off using multiple laser beams. The clinical and neonatal outcomes of the laser‐treated group and non‐treatment control were analyzed.ResultsIn the laser‐assisted hatching group, significantly higher rates of clinical pregnancy (40.8% vs 29.4%, P < .01) and live delivery (34.3% vs 22.5%, P < .01) were observed compared to the control group. Other variables such as the average gestational weeks, the sex of the baby, birthweight, or congenital malformations were found to have no significant differences in neonatal outcomes. Moreover, all babies were singleton live births.ConclusionsSingle vitrified blastocyst transfer treated with laser‐assisted hatching increases the live birth rate and has no adverse effects on neonatal outcomes.

Effects of Laser Assisted Hatching on Pregnancy Outcomes of Frozen Embryo Transfer Cycles

The implantation of the embryo into the uterus requires hatching from its zona pellucida (ZP). The inability of the embryo to break its zona pellucida is considered as a factor for implantation failure. Assisted hatching (AH) is performed to make it easier for natural hatching to occur, also providing early embryoendometrium contact, which favors the embryos implantation into the uterus. To evaluate the effect of laser assisted hatching (LAH) on pregnancy rate in frozen embryo transfer cycle.  Materials &amp; methods: In a prospective observational study a total of 80 patients who underwent frozen embryo transfer(FET) cycles were included in the study. Patients were divided into Laser assisted hatching group (LAH) and no LAH group. In the LAH group, zona thinning was done with the help of laser just prior to the embryo transfer. In the control group no hatching was done before transfer. The main outcome measures were pregnancy rate &amp; implantation rate. The baseline characteristics of the 80 patients included in the study ie.,LAH group (n=40) vs no LAH group (n=40),the mean age ( 30.855.4 vs 333.9),mean BMI (25.64.1 vs 27.94.5),duration of infertility ( 6.184.1 vs 8.534.7) , number of embryos transferred (2.750.8 vs 2.70.72) respectively. Younger women &lt; 30 years in no LAH group had higher pregnancy rate compared to the LAH group. Between the two groups, patients between 31-35 years in LAH group had higher pregnancy rate compared to no LAH group. The pregnancy rate (42.85% vs 54.5%) in LAH group of women &gt;35years found lower than the no LAH group. LAH seems to be beneficial in women between 31- 35 years of age group, but LAH does not seem to be beneficial in women &gt; 35 years of age. There is slight increase in pregnancy rates with laser assisted zona thinning in frozen transfer cycle, but it is not statistically significant.

Thinning and drilling laser-assisted hatching in thawed embryo transfer: A randomized controlled trial.

ObjectiveIn frozen and thawed embryos, the zona pellucida (ZP) can be damaged due to hardening. Laser-assisted hatching (LAH) of embryos can increase the pregnancy rate. This study compared thinning and drilling of the ZP before frozen embryo transfer (FET).MethodsPatients were randomly allocated into two groups for LAH using thinning or drilling on day 2 after thawing. Twenty-five percent of the ZP circumference and 50% of the ZP thickness was removed in the thinning group, and a hole 40 µm in diameter was made in the drilling group.ResultsA total of 171 in vitro fertilization/intracytoplasmic sperm injection FET cycles, including 85 cycles with drilling LAH and 86 cycles with thinning LAH, were carried out. The thinning group had a similar β-human chorionic gonadotropin-positive rate (38.4% vs. 29.4%), implantation rate (16.5% vs. 14.4%), clinical pregnancy rate (36.0% vs. 25.9%), miscarriage rate (5.8% vs. 2.4%), ongoing pregnancy rate (30.2% vs. 23.5%), and multiple pregnancy rate (7.0% vs. 10.6%) to the drilling LAH group. There were no significant differences in pregnancy outcomes between subgroups defined based on age (older or younger than 35 years) or ZP thickness (greater or less than 17 µm) according to the LAH method.ConclusionThe present study demonstrated that partial ZP thinning or drilling resulted in similar outcomes in implantation and pregnancy rates using thawed embryos, irrespective of women's age or ZP thickness.

The use of laser assisted hatching of frozen/thawed embryos versus laser assisted hatching of fresh embryos in human intracytoplasmic sperm injection

Cryopreservation of human embryos has become an essential part of assisted reproduction. It limits the number of embryo transferred while supernumerary embryos can be transferred in subsequent cycles, however, it is associated with zonal hardening, which lowers the success rate in the majority of (ICSI) centres, associated with decreased implantation rate and clinical pregnancy rates. Assisted hatching has been used to induce microdissection of the zona pellucida. Many techniques have been used, such as mechanical, chemical, piezo and laser techniques.Aim: To compare the efficacy of laser assisted hatching of vitrified embryos and fresh embryos with regards to implantation rate and clinical pregnancy rate.Study design: Prospective randomised study.Patients and methods: One hundred twenty women with fresh embryos scheduled for (ICSI) were randomised in two groups; laser assisted hatching (LAH) group (test group), containing 60 women and the other is (non LAH) (control group). Second group with 120 women with frozen embryos were randomised in (LAH group) and (non LAH group). On the day of embryo transfer, 1.48 μm Infrared Diode laser, class 1 M, was used in test group to induce zonal microdissection, the quality and safety of embryos is assessed morphologically after hatching. On the other hand, the zona of the control group were left intact. Both clinical pregnancy and implantation rates were estimated.Results: Laser assisted hatching group had clinical pregnancy and implantation rates of 38% and 50%, respectively. Non laser assisted hatching group had lower clinical pregnancy and implantation rates; 30% (p = .442) and 33% (p = .095), respectively, with no statistically significant difference p < .05.Conclusion: LAH does not improve statistically both pregnancy rate and implantation rate in fresh embryos. However, there is improvement in both implantation and pregnancy rate in Vitrified group.

Epigenetic changes in preimplantation embryos subjected to laser manipulation.

The advantage of using laser for assisted hatching in routine assisted reproductive technology (ART) practice is debatable. Recently, it has been shown that laser-manipulated mouse embryos had compromised genetic integrity. However, the impact of laser-assisted hatching (LAH) on the epigenetic integrity of the preimplantation embryos is not elucidated so far. Since continuous thermal stress on embryos was found to lower mRNA levels of de novo (bovine) methyl transferases in embryos, we hypothesize that thermal energy induced during LAH may alter the epigenetic signature through abnormal de novo methyl transferases (Dnmts) levels. Thus, using mouse model, we made an attempt to look into the expression of Dnmt3a and Dnmt3b in laser-manipulated embryos and their effects on global methylation. This experimental prospective study used mouse embryos from varying developmental stages (2-cell, 6-8-cell, and blastocyst) which were subjected to LAH using a 1480-nm diode laser. Two pulses of 350μs frequency were applied to breach the zona pellucida, and then, embryos were assessed for the expression of two de novo methyl transferases (Dnmt3a and Dnmt3b) and LINE-1 (long interspersed element-1) methylation when LAH embryos developed to blastocyst stage. Results from this study have shown that blastocysts subjected to LAH at two-cell stage had significantly lower mRNA transcripts of Dnmt3a (P<0.01) and Dnmt3b (P<0.05) whereas LAH at six- to eight-cell and blastocyst stages did not affect the mRNA level significantly. On the other hand, LINE-1 methylation did not change significantly between LAH and control group in all the stages studied. These results suggest that two-cell-stage laser manipulation of embryos changes the mRNA level of Dnmts without affecting the global DNA methylation.

Prospective randomized trial on the use of laser assisted hatching for transfer of frozen/thawed embryos in human Intracytoplasmic Sperm injection

Abstract Background Cryopreservation of human embryos has become an essential part of assisted reproduction, however it might be associated with zonal hardening, which could reduce implantation rate and clinical pregnancy rates. Assisted hatching has been used to induce microdissection of the zona pellucida. Many techniques have been used, such as mechanical, chemical, piezo and laser techniques. Objective To determine if laser assisted hatching improves both the implantation and clinical pregnancy rates in women using transferred frozen/thawed embryos. Study design Prospective randomized study. Patients and methods 160 women, scheduled for transfer of cryopreserved embryos, were randomized in two equal groups using sealed envelopes; a laser assisted hatching group (test group), and a control group, each included 80 women. On the day of embryo transfer, Diode laser was used in test group to induce zonal microdissection, the quality and safety of embryos is assessed morphologically after hatching. On the other hand, the zona of the control group were left intact. Both implantation and clinical pregnancy rates were estimated. Results Laser assisted hatching group had implantation rates and clinical pregnancy of 50% and 37.5% respectively. Non laser assisted hatching group had lower implantation rates and clinical pregnancy; 47.27% (P value = 0.87) and 27.5% (P value = 0.237) respectively. Conclusion Laser assisted hatching seems to improve both the clinical pregnancy and implantation rates amongst patients using frozen/thawed embryos, however that was statistically insignificant.

The impact of laser-assisted hatching on the outcome of frozen human embryo transfer cycles.

Biochemical modifications of zona pellucida (ZP) result in zona hardening. Zona hardening (ZH) is induced by several factors such as advancing maternal age, in vitro culture conditions and cryopreservation and adversely effects implantation. The objective of the clinical study was to determine whether or not laser-assisted hatching (LAH) applied on day 3 frozen embryos improves the outcome of frozen embryo transfer (FET) cycles in patients with recurrent implantation failure and/or advanced female age. In total, 413 patients of different ages with recurrent implantation failure (maximum three cycles) were involved into the study. Patients were allocated randomly into LAH and control groups. On the day of FET, after thawing and just before FET, the ZP was thinned using a laser system. In the control group no treatment was applied on frozen embryo before transfer. The main outcome measures were clinical pregnancy rate. Overall, the results indicate a tendency that LAH increased (P = 0.08) clinical pregnancy. However, for patients older than 37 years, LAH increased pregnancy rates significantly (P = 0.03). In the LAH and control groups, the age of patients and the number of transferred embryos influenced pregnancy rates (P = 0.01). For patients older than 37 years, no effect of number of transferred embryos was detected (P = 0.14). The incidence of multiple pregnancies also increased in the LAH group (P = 0.01). In conclusion, in older woman, to overcome the negative effect of zona hardening, LAH could be performed on frozen embryos as a routine strategy before FET in frozen cycles in order to increase the possibility of pregnancy formation.

No adverse effects were identified on the perinatal outcomes after laser-assisted hatching treatment

The aim of this study was to evaluate the safety of laser-assisted hatching (LAH) by comparing obstetric and neonatal outcomes between assisted hatching and control groups in cryopreserved embryo transfer cycles. A retrospective cohort analysis was carried out. A total of 699 women with 392 infants delivered were included. Laser- assisted hatching was carried out on D-3 thawed and warmed embryos before transfer in 480 cryopreserved embryos transfer cycles. Obstetric outcomes, neonatal outcomes, and congenital birth defects were recorded. A total of 815 cryopreserved embryo transfer cycles (480 in LAH group and 335 in control group) in 699 patients were analysed. Statistically significantly higher implantation (31.85% versus 16.95%), clinical pregnancy (53.96% versus 33.43%) and live delivery (44.58% versus 23.88%) rates were observed in the LAH group (all P < 0.001). For either singleton or multiple gestations, no statistically significant differences were found in mean gestational age, mean birth weight and mean Apgar score. Four major malformations occurred in the assisted hatching group and three malformations (one major and two minor) in the control group. This study did not identify any harmful effect of LAH on neonates, which suggested that LAH may be a safe treatment in cryopreserved embryo transfer cycles.

Effect of laser assisted hatching (LAH) on fresh blastocysts and clinical outcomes

The purpose of this study was to evaluate the clinical outcomes of LAH performed on fresh-day 5 blastocysts prior to transfer. This was a retrospective matched case-control study which included patients who underwent a fresh-day 5 blastocyst transfer between May 2013 and April 2014 at the MUHC Reproductive Centre. Patients undergoing fresh stimulated cycles as well as in-vitro maturation cycles were included in this study. Blastocysts were collapsed first using the laser then had LAH performed on the same side as the inner cell mass. Approximately 5-8 laser pulses were delivered in order to completely rupture the zona pellucida (ZP) along roughly ¼ of its diameter. Early stage blastocysts did not undergo shrinking prior to LAH but an opening in the zona was created via 2-3 laser pulses ensuring that the inner ZP layer had been breached. A control group was generated from fresh day 5 blastocyst transfer cycles that did not undergo LAH. Characteristic differences among the groups were analyzed using Z-test or Student’s t-test and outcomes were compared using chi-square test and Fisher’s exact test when appropriate. A P-value <0.05 was considered significant. A total of 208 cycles were included in the study, 104 in each group. The two groups were comparable in that there were no significant differences in age, serum FSH level, antral follicle count, stimulation protocol or cause of infertility. Additionally, the number of oocytes collected and fertilized as well as the number of embryos transferred and implanted did not differ. The overall pregnancy rate and clinical pregnancy with fetal cardiac activity in the LAH group were 56.73% and 40.38% and in the control group were 49.04% and 36.54% respectively. Among women over 40 years old, the implantation rate was 28.57% in the LAH group compared to 8.33% in the control group (p<0.05). Similarly, the rate of pregnancy with fetal cardiac activity was higher in the study group than in the control group (32.14% vs. 8.33%, p<0.05). Women over 40 years old have a decreased pregnancy rate. Assisted hatching of fresh blastocysts can benefit older patients who traditionally have lower chances of success.

Effect of laser assisted hatching on outcome of assisted reproductive technology

Objective: To determine whether laser-assisted hatching can improve clinical outcome of assisted reproductive techniques in both unselected patients and patients with advanced female age, with recurrent implantation failure, or who are using frozen-thawed embryos. Study design: Prospective randomized study. Patients and methods: 179 consecutive women scheduled for intracytoplasmic sperm injection (ICSI) were randomised to either laser assisted hatching (LAH) or non LAH group. Patients were divided into 94 test and 85 control groups. On the day of embryo transfer, the zona pellucida of the selected embryos in the test group was thinned by using an infrared optical laser system, whereas in the control group they were left intact. Clinical pregnancy rates (CPR) and implantation rates (IR) were estimated. Result(s): Patients that underwent LAH (n = 94) had CPR, and IR of 35.1% and 50%, respectively. Patients that did not undergo LAH (n = 85) had lower CPR (28.2%, P = 0.324) and IR (33%, P = 230), with no statistically significant difference P Conclusion: The current study suggested that there is no need for the routine use of laser assisted hatching. However, there is evidence of laser assisted hatching benefit in selected patients

Laser versus mechanical assisted hatching: a prospective study of clinical outcomes

To compare clinical outcomes after laser or mechanical techniques of assisted hatching (AH) in women of advanced age undergoing IVF or intracytoplasmic sperm injection (ICSI). Prospective randomized study. Center for Human Reproduction, Genesis Clinic, Athens, Greece. Three hundred and sixteen consenting women of advanced age (> or =39 years) with primary infertility undergoing IVF/ICSI programs and having available embryos for transfer on day 3. Patients were randomized into laser or mechanical AH of their transferred embryos. Controlled ovarian hyperstimulation, oocyte retrieval, IVF/ICSI, laser or mechanical AH, and embryo-transfer. Implantation rate, clinical pregnancy rate, and viable pregnancy rate. The implantation rate was significantly higher in the laser AH group. Clinical and viable pregnancy rates were higher (but not significantly) in the laser AH group. Laser AH of embryos may result in better clinical outcomes when compared to the mechanical technique in women of advanced age undergoing IVF or ICSI.

Laser-assisted hatching increases pregnancy and implantation rates in cryopreserved embryos that were allowed to cleave in vitro after thawing: a prospective randomized study

Cryopreservation of embryos may lead to zona hardening that may compromise in vivo hatching and implantation following thawing and transfer. Assisted hatching (AH) has been advocated as a means of assisting the natural hatching process and enhancing implantation. The aim of this study was to assess in a prospective randomized manner the effect of laser-assisted hatching (LAH) on implantation as well as clinical and multiple pregnancy rates (the primary outcome) after the transfer of frozen-thawed embryos. All embryos were thawed the day before transfer, and LAH was performed the next day on embryos that cleaved. Control group consisted of embryos that were transferred without AH. The performance of LAH significantly increased implantation (9.9 versus 20.1%, P < 0.01), clinical pregnancy (27.3 versus 40.9, P < 0.05) and multiple pregnancy rates (16 versus 40.3%, P < 0.07). In the LAH group, significantly more excess embryos that were left in culture hatched in vitro. LAH improves the outcome of frozen-thawed embryo transfer when performed before transfer on embryos that were allowed to cleave.

Efficacy of Laser Assisted Hatching using a 1.48-μm Diode Laser in Human Embryo

The aim of the present study was to assess the efficacy of laser assisted hatching (LAH) in human embryos. Embryos were assigned to one of two groups: LAH group (n=24) or control group (n=19). In the LAH group, zona opening was performed at the day 3 embryo with the use of a 1.48-μm infrared diode laser (OCTAX Laser Shot™ system, MTG Medical Technology, Altdorf, Germany). Following the LAH, embryos were cultured up to the hatching blastocyst stage to determine whether the LAH resulted in damage to subsequent development. The LAH was performed on 14 patients who experienced IVF/ICSI failures in two or more cycles in our clinic. Respective blastocyst development rates in the LAH and the control group were 37.5% (9/24) and 42.1% (8/19). There was no significant difference between the two groups. As rates of blastocyst hatching were 88.9% (8/9) and 12.5% (1/8), respectively, the LAH group showed a significant increase as compared to the control group (P<0.01). To date, five pregnancies have occurred following the transfer of zona opening day 3 embryos. LAH of human embryos does not have an adverse effect on subsequent development and increases the rate of blastocyst hatching.

Does laser assisted hatching of residual embryos on day 3 affect blastocyst development?

To prospectively determine the impact of Laser Assisted Hatching (LAH) on blastocyst formation in spare, non-transferred day 3 embryos. Spare, non-transferred embryos were randomized prospectively on day 3 to LAH or non-LAH based on odd/even number designation. All hatched embryos designated for actual or possible transfer were excluded from the analysis. All spare embryos containing at least 2 blastomeres on day 3 were included. For this prospective study, the two-tailed power analysis calculation was based on a prior spare blastocyst formation rate of 35%, with a clinically relevant range deemed to be 20% to 50%. To reach 80% power with an alpha error less than 0.05, our analysis required 138 embryos in the LAH and non-LAH group. The study required approximately 12 months. Oocytes were retrieved in HTF (InVitrocareyr—IVC, Frederick, MD), hyaluronidased after 2 to 3 hours incubation and ICSI’ed one to three hours following cumulus-corona removal. Oocytes were placed in IVC-1 (IVC) after ICSI and cultured individually in this media until Day 3. Embryos were placed into CCM (Vitrolife, Denver, CO) on the morning of Day 3 for extended culture. The best embryos were identified and laser hatched prior to transfer using the Zilos laser system from Hamilton Thorne (settings: one pulse; 0.500 milliseconds duration). After transfer, all remaining odd numbered embryos were assisted hatched. Even numbered embryos were left alone. Morphologic assessment occurred on Day 2, 3, 5 and 6. Blastocysts were cryopreserved on Day 5, 6 or 7. All transfers occurred on Day 3 using a Wallace 23cm stylet (Irvine Scientific, Irvine, CA) and Cook Echotip Catheter (Cook OB/GYN, Spencer, IN) under abdominal ultrasound guidance and were performed by the same physician. In the 34 patient cycles included in this study, 67.6% resulted in pregnancy after transfer with an implantation rate of 37%. In these 34 cycles, 157 embryos were designated to the laser-hatching group and 153 were not assisted hatched. Forty-three laser-hatched embryos reached the blastocyst stage (27.4%) and were cryopreserved. Forty non-laser assisted-hatched embryos developed to blastocysts (26.1%) and were cryopreserved. Blastocyst formation rates between the two groups did not reach statistical significance. (Chi-Square, p=0.80455246). Assisted hatching of non-transferred embryos by retrospective analysis had previously shown a small, but statistically significant enhancement in blastocyst formation (Portmann et al., ASRM, 2003). The results of that study were potentially skewed by the inclusion of higher quality hatched, but non-transferred embryos. In this prospective analysis, and with better randomization, there appears to be no impact of laser hatching upon embryo development to the blastocyst stage. This finding, albeit with a relatively small number of embryos, is reassuring as assisted hatching techniques shift towards greater utilization of the laser.

Laser-assisted hatching of embryos is better than the chemical method for enhancing the pregnancy rate in women with advanced age

Objective: Assisted hatching may enhance embryo implantation. This study was conducted to examine the efficacy of the laser- and chemical-assisted hatching for promotion of implantation (IR), pregnancy (PR), and delivery rate (DR) in older women undergoing IVF cycles. Design: Prospective study. Setting: An IVF unit of a medical center. Patient(s): A total of 601 embryos from 141 women aged ≥38 years underwent controlled ovarian hyperstimulation (COH) and assisted hatching. Intervention(s): The study population was divided into two groups: group 1 had laser-assisted hatching (n = 85) and group 2 had chemical-assisted hatching (n = 56). Before the transfer, the day 3 embryos were hatched by using a 1.48-μm noncontact diode laser or acid Tyrode’s solution. Main Outcome Measurement(s): The IR, PR, and DR between the groups were compared. Result(s): There were no statistical differences between groups in age, E 2 concentrations during hCG administration, gonadotrophin dosage, embryo grade, the numbers of oocytes retrieved, oocytes fertilized, and embryos transferred. Higher IR, PR, and DR were noted in the laser-assisted hatching group. The IR, PR, and DR were: group 1, 8.2%/31.8%/24.7% and group 2, 3.8%/16.1%/10.7%, respectively. Conclusion(s): Laser-assisted hatching of embryos is more effective than the chemical method in enhancing the IR and PR of women with advanced age. The laser system allows an easier, faster, and safer micromanipulation of the zona pellucida, which provided a better method in zona drilling.