Effects of three-area laser-assisted zona thinning in 8-cell human embryos on pregnancy outcomes in vitro fertilization / 대한생식의학회지

OBJECTIVE: This study conducted a preliminary examination of the effects of three-area laser-assisted zona thinning (LAZT) during the cleavage stage of embryo development on the hatching process in human in vitro fertilization-embryo transfer (IVF-ET) with subjects of advanced female age or frozen-thawed (FT) embryos. METHODS: Eight-cell stage embryos were treated with LAZT in three areas of the zona pellucida at 120° intervals. The control group was embryos without LAZT. Of the 72 consecutive fresh cycles and the 28 FT embryo transfer cycles, the patients in 55 fresh cycles and 17 FT cycles declined LAZT, and those cycles were defined as the control group. RESULTS: In the fresh cycles, the pregnancy rates were similar in the LAZT and control groups. However, in the FT cycles, the pregnancy rate was significantly higher in the LAZT group than in the control group (45.5% in the LAZT group vs. 23.5% in the control group, p < 0.05). CONCLUSION: These results show that multi-area LAZT resulted in significantly improved pregnancy outcomes in human 8-cell embryos compared to controls.

Assisted Hatching in Couples with Advanced Maternal Age: A Systematic Review and Meta-analysis / 华中科技大学学报（医学）（英德文版）

This systematic review aimed to evaluate the efficacy and safety of assisted hatching (AH) performed in couples with advanced maternal age.We searched for randomized controlled trials (RCTs) in electronic databases,including MEDLINE,EMBASE and CENTRAL (from inception to January 2018);in addition,we hand-searched the reference lists of included studies and similar reviews.We included RCTs comparing AH versus no treatment (control).The meta-analysis was performed by RevMan 5.3 software.The search retrieved 943 records and 8 RCTs were included,comprising 870 cycles (n=440 for AH,and n=430 for control).There was no significant difference in the rates of live birth (RR 0.88,95％ CI 0.65 to 1.18,3 RCTs,n=427,I2=0％),clinical pregnancy (RR 1.00,95％ CI 0.83 to 1.19,8 RCTs,n=870,I2=22％),implantation (RR 1.07,95％ CI 0.83 to 1.39,4 RCTs,n=1359,I2=0％),miscarriage (RR 1.13,95％ CI 0.66 to 1.94,2 RCTs,n=116,I2=0％) and multiple pregnancy (RR 0.89,95％ CI 0.31 to 2.52,1 RCT,n=97,I2=not applicable) between the treatment group and control group.No reasonable conclusions could be drawn regarding reproductive outcomes after AH in patients with advanced maternal age due to the small sample pooled in meta-analyses.Studies of high methodological quality and with adequate power are necessary to further investigate the value of AH in assisted conception of those patients.

Assisted Hatching in Couples with Advanced Maternal Age: A Systematic Review and Meta-analysis / 华中科技大学学报（医学）（英德文版）

This systematic review aimed to evaluate the efficacy and safety of assisted hatching (AH) performed in couples with advanced maternal age.We searched for randomized controlled trials (RCTs) in electronic databases,including MEDLINE,EMBASE and CENTRAL (from inception to January 2018);in addition,we hand-searched the reference lists of included studies and similar reviews.We included RCTs comparing AH versus no treatment (control).The meta-analysis was performed by RevMan 5.3 software.The search retrieved 943 records and 8 RCTs were included,comprising 870 cycles (n=440 for AH,and n=430 for control).There was no significant difference in the rates of live birth (RR 0.88,95％ CI 0.65 to 1.18,3 RCTs,n=427,I2=0％),clinical pregnancy (RR 1.00,95％ CI 0.83 to 1.19,8 RCTs,n=870,I2=22％),implantation (RR 1.07,95％ CI 0.83 to 1.39,4 RCTs,n=1359,I2=0％),miscarriage (RR 1.13,95％ CI 0.66 to 1.94,2 RCTs,n=116,I2=0％) and multiple pregnancy (RR 0.89,95％ CI 0.31 to 2.52,1 RCT,n=97,I2=not applicable) between the treatment group and control group.No reasonable conclusions could be drawn regarding reproductive outcomes after AH in patients with advanced maternal age due to the small sample pooled in meta-analyses.Studies of high methodological quality and with adequate power are necessary to further investigate the value of AH in assisted conception of those patients.

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

OBJECTIVE: In 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). METHODS: Patients 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. RESULTS: A 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. CONCLUSION: The 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.

Related factors of monozygotic twins in IVF/ICSI-ET / 实用医学杂志

Objective To analyze the phenomenon of monozygotictwin(MZT)in in vitro fertilization/intra-cytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET),and explore possible laboratory-related factors that may contribute to MZT. Methods Patients who transferred single embryo in our center from January 2015 to October 2016,including 1786 fresh embryo transfer cycles and 1710 thawed embryo transfer cycles and 49 preimplantation genetic diagnoses(PGD)cycles,were retrospectively analyzed. Correlation between fresh embryo,embryo freez-ing and thawing,embryo quality,artificial assistant hatching and MZT were analyzed. Results (1)There was no significant difference in the MZT rate between embryo age ,in vitro culturing time and in vitro fertilization mode (P > 0.05).(2)The MZT rate between fresh blastocysts and frozen-thawed blastocysts showed significant differ-ence(0.88%vs. 3.08%,P<0.05).(3)The incidence of MZT was significantly higher in laser hatching than that in mechanical hatching in PGD(25.00% vs. 0.00%,P < 0.05). Conclusion Frozen and assisted incubation of blastocyst are risk factors for MZT.

Effects of laser-assisted hatching and exposure time to vitrification solution on mouse embryo development / 대한생식의학회지

OBJECTIVE: This study was conducted to investigate the efficacy of laser-assisted hatching (LAH) and various vitrification times for embryonic development and blastocyst cell numbers. METHODS: First, 2-cell and 8-cell embryos were collected by flushing out the oviducts. In the control groups, they were vitrified for 8 or 10 minutes without LAH. The LAH groups underwent quarter laser zona thinning-assisted hatching before vitrification (4, 6, and 8 minutes or 4, 7, and 10 minutes, respectively). After incubation, double-immunofluorescence staining was performed. RESULTS: The hatched blastocyst rate 72 hours after the 2-cell embryos were thawed was significantly higher in the 2LAH-ES8 group (33.3%) than in the other groups (p < 0.05). In the control-8 group (22.1±4.6), the cell number of the inner cell mass was higher than in the LAH groups (p < 0.05). The number of trophectoderm cells was higher in the 2LAH-ES6 group (92.8±8.9) than in the others (p < 0.05). The hatched blastocyst rate 48 hours after the 8-cell embryos were thawed was higher in the 8LAH-ES4 group (45.5%) than in the other groups, but not significantly. The inner cell mass cell number was highest in the 8LAH-ES7 group (19.5±5.1, p < 0.05). The number of trophectoderm cells was higher in the 8LAH-ES10 group (73.2±12.1) than in the other groups, but without statistical significance. CONCLUSION: When LAH was performed, 2-cell embryos with large blastomeres had a lower hatched blastocyst rate when the exposure to vitrification solution was shorter. Conversely, 8-cell embryos with small blastomere had a higher hatched blastocyst rate when the exposure to vitrification solution was shorter.

Effect of laser-assisted hatching on outcome of frozen-thawed embryo transfer for patients with previous repeated implantation failure / 第二军医大学学报

Objective To determine whether laser-assisted hatching (LAH) can improve the clinical outcome of frozen-thawed embryo transfers (FET) for patients with previous repeated implantation failure. Methods A total of 97 infertility patients with previous repeated failure, who received assisted reproductive therapy in our in-vitro fertilization(IVF) center from May 2012 to December 2013, were included in this study. A total of 124 FET cycles were randomly divided into LAH group (LAH was performed before embryo transplantation, n=61) and non-assisted hatching group (LAH was not performed before embryo transplantation, n=63). The clinical pregnancy rate,implantation rate, abortion rate and multiple pregnancy rate were compared between the two groups. Results The pregnancy rate (47.5% vs 30.2%,P0.05). Conclusion The LAH can increase the pregnancy and implantation rates and improve the outcome of IVF-ET in frozen-thawed embryo transfer cycles for patients with previous repeated failure.

The effect of artificial shrinkage and assisted hatching on the development of mouse blastocysts and cell number after vitrification / 대한생식의학회지

OBJECTIVE: The goal of this study was to ascertain optimal assisted hatching (AH) method in frozen embryo transfer. We compared the effect of depending on whether mechanical or laser-AH was performed before or after the vitrification of embryo development rate and blastocyst cell numbers. METHODS: In order to induce superovulation, pregnant mare's serum gonadotropin followed by human chorionic gonadotropin were injected into 4- to 5-week-old female mice. 2-cell embryos were then collected by flushing out the oviducts. The Expanded blastocysts were recovered after the collected embryos were incubated for 48 hours, and were then subjected to artificial shrinkage (AS) and cross-mechanical AH (cMAH) or quarter-laser zona thinning-AH (qLZT-AH) were carried out using the expanded blastocysts before or after vitrification. After 48 hours of incubation, followed by vitrification and thawing (V-T), and blastocysts were fluorescence stained and observed. RESULTS: The rate of formation of hatched blastocysts after 24 and 72 hours of incubation was significantly higher in the AS/qLZT-AH/V-T group than in the other groups (p<0.05). The cell number of the inner cell mass was higher in AS/V-T/non-AH and AS/V-T/cMAH groups than those of others (p<0.05). In the control group, the number of trophectoderm and the total cell number were higher than in the AS-AH group (p<0.05). CONCLUSION: The above results suggest that AS and AH in vitrification of expanded blastocysts lead to the more efficient formation of hatched blastocysts in mice.

Research progress on the regulatory mechanisms of mammalian blastocyst hatching / 军事医学

Prior to implantation, the blastocyst has to hatch out of its zona pellucida to invade the endometrium .In mammals including humans , failure of blastocyst hatching leads to infertility .Blastocyst hatching is believed to be regulated by a variety of autocrine and paracrine molecules such as proteases , cyclooxygenase-2, p38 mitogen-activated protein ki-nase, activin A and Wnt signal pathway .This article reviews the mechanisms of the key molecular regulators involved in mammalian blastocyst hatching and hatching-assisting methods , which can help clarify the mechanism of blastocyst hatching and the treatment of infertility due to failure in blastocyst hatching .

The effect of various assisted hatching techniques on the mouse early embryo development / 대한생식의학회지

OBJECTIVE: In search of an ideal method of assisted hatching (AH), we compared the effects of conventional micropipette-AH and laser-AH on the blastocyst formation rate (BFR) and blastocyst cell numbers. METHODS: Four- to five-week-old ICR female mice were paired with male mice after superovulation using Pregnant mare's serum gonadotropin (PMSG) and hCG. The two-cell embryos were flushed from the oviducts of female mice. The retrieved two-cell embryos underwent one of five AH procedures: single mechanical assisted hatching (sMAH); cross mechanical assisted hatching (cMAH); single laser assisted hatching (sLAH); quarter laser assisted hatching (qLAH); and quarter laser zona thinning assisted hatching (qLZT-AH). After 72 hours incubation, double immunofluorescence staining was performed. RESULTS: Following a 72 hours incubation, a higher hatching BFR was observed in the control, sMAH, cMAH, and sLAH groups, compared to those in the qLAH and qLZT-AH groups (p<0.05). The hatched BFR was significantly higher in the qLAH and qLZT-AH groups than in the others (p<0.05 for each group). The inner cell mass (ICM) was higher in the control and sMAH group (p<0.05). The trophectoderm cell number was higher in the cMAH and qLAH groups (p<0.05). CONCLUSION: Our results showed that the hatched BFR was higher in groups exposed the the qLAH and qLZT-AH methods compared to groups exposed to other AH methods. In the qLAH group, although the total cell number was significantly higher than in controls, the ICM ratio was significantly lower in than controls.

Clinical outcomes of vitrified-thawed embryo transfer using a pull and cut straw method

OBJECTIVE: To compare the clinical outcomes of patients with vitrified-thawed embryos transferred using either the 0.25 mL straw method and the pull and cut straw (PNC) method. To evaluate the clinical outcomes of patients with transferred embryos that underwent assisted hatching at the cleaved embryo (day 3) or the blastocyst (day 5) stage. METHODS: The study population consisted of women who underwent vitrified-warmed embryo transfer between May 2000 and December 2011 and assisted hatching was performed after warming of embryos. Cycles of thawing between assisted hatching treated and non treated groups were compared for survival and pregnancy rates. RESULTS: The PNC vitrification method improved survival and pregnancy rates in partial lysed embryos. While assisted hatching did not affect the developmental and clinical pregnancy rates of the vitrified-warmed blastocyst group, it did increase the pregnancy rate of poor quality vitrified-warmed cleaved embryos. CONCLUSION: These results suggest that PNC may increase the number of clinical pregnancies via the vitrification of both cleaved embryos and blastocysts. In addition, selective assisted hatching treatment of embryos that show a poor prognosis after warming may increase the rate of clinical pregnancy.

Effect of artificial shrinkage on clinical outcome in fresh blastocyst transfer cycles / 대한생식의학회지

OBJECTIVE: This study aimed to determine the safety and clinical effect of artificial shrinkage (AS) in terms of assisted hatching of fresh blastocysts. Also, we evaluated the correlation between patient age and the effect of AS on clinical outcome. METHODS: Two AS methods, using a 29-gauge needle and laser pulse, were compared. Seventy-three blastocysts were shrunk using a 29-gauge needle and the same number of other blastocysts were shrunk by a laser pulse. We evaluated the shrunken blastocysts hourly and considered them viable if they re-expanded >70%. Blastocyst transfer cycles (n=134) were divided into two groups: a control group consisted of the cycles whose intact embryos were transferred (n=100), while the AS group consisted of the cycles whose embryos were replaced following AS (n=34). The implantation and pregnancy rates of the control group and AS group were compared (p<0.05). RESULTS: The re-expansion rates of the 29-gauge needle and laser pulse AS groups were similar (56 [76.7%] vs. 62 [84.9%], respectively). All of the remaining shrunken blastocysts were re-expanded within 2 hours. There was no degeneration of shrunken blastocysts. The total and clinical pregnancy rate of the AS group (23 [67.6%]; 20 [58.8%], respectively) was significantly higher than that of the control group (47 [47.0%]; 39 [39.0%], respectively). In the older patient group, there was no difference in the clinical outcomes between the AS and control groups. CONCLUSION: These results suggest that AS of blastocoele cavity, followed by the transfer, would be a useful approach to improve the clinical outcome in cycles in which fresh blastocyst stage embryos are transferred.

Clinical Efficacy of Assisted Hatching with Partial Zona Dissection in Intrauterine Embryo Transfer / 대한산부인과학회잡지

OBJECTIVE: To investigate the clinical efficacy of assisted hatching (AH) with partial zona dissection (PZD) in intrauterine embryo transfer in the patients who failed more than 2 times with standard IVF-ET protocol (Group R), were more than 37 years old (Group A), or had high basal serum FSH levels more than 15 mIU/ml (Group F). METHODS: From January, 1998 to June, 2002, 156 cycles of AH with partial zona dissection were performed in 117 infertile patients in Department of Obstetrics and Gynecology, Seoul National University Hospital. The outcomes of AH were analyzed according to pregnancy rate. RESULTS: The number of oocytes retrieved after controlled ovarian hyperstimulation (COH) was 8.3 +/- 5.2 in 104 cycles of 75 patients who failed more than 2 times with standard IVF-ET protocol (Group I: Groups R, R+A, R+F, and R+A+F), 7.7 +/- 5.0 in 82 cycles of 67 patients who were more than 37 years old (Group II: Groups A, R+A, A+F, and R+A+F), and 7.2 +/- 4.9 in 38 cycles of 30 patients who had high basal serum FSH levels more than 15 mIU/ml (Group III: Groups F, R+F, A+F, and R+A+F). The number of embryos transferred after AH was 4.1 +/- 1.5 in Group I, 3.7 +/- 1.3 in Group II, and 4.0 +/- 1.7 in Group III. The mean cumulative embryo score (CES) was 81.9 +/- 46.5 in Group I, 75.9 +/- 43.0 in Group II, and 75.7 +/- 40.2 in Group III. There were no significant differences in the numbers of oocytes retrieved, embryos transferred and CES among 3 groups. The overall clinical pregnancy rate was 22.4% (35/156) per cycle and 29.9% (35/117) per patient. The clinical pregnancy rate per cycle and per patient was 18.3% (19/104) and 25.3% (19/75) in Group I, 15.9% (13/82) and 19.4% (13/67) in Group II, and 31.6% (12/38) and 40.0% (12/30) in Group III, and there was a significant difference between Group II and Group III. CONCLUSION: AH of human embryos with PZD might be promising for the improvement of pregnancy rates, especially in the patients with the past history of repeated failure, old age, or high basal serum FSH level.

A Case of Diamnionic Monochorionic Monozygotic Twin Which was Conceived by In Vitro Fertilization / 대한산부인과학회잡지

Monozygotic twinning is a relatively rare event in vivo conception, being estimated to occur in 0.42% of all birth. The underlying mechanism for monozygotic twin formation is the division of the embryo early in its development. Separation of cells may theoretically occur before or after inner cell mass formation. The incidence of monozygotic twinning following assisted reproduction techniques is higher than the commonly accepted incidence after in vivo conception. Patients at particular risk of monozygotic twins are those aged > 35 years and those who had manipulation techniques for assisted fertilization. Hence, it seems prudent to counsel these patients about the potential obstetric complications of monozygotic multiple gestations prior to the initiation of their treatment.

Effect of Partial Laser Assisted Hatching on Mouse Embryos / 대한불임학회지

OBJECTIVE: The present study was performed to investigate the efficiency of partial laser assisted hatching (p-LAH; lased 1/2 ZP width from ZP edge) on hatching of mouse blastocysts. METHODS: We used non-contact 1.48 micrometer diode laser (MTM, Switzland) to create a precise hole on zona pellucida. 2-cell embryos were collected from the mouse (ICR) oviduct at 48 hours after hCG administration. Collected 2-cell embryos were cultured in the P-1 medium supplemented with 0.4% BSA. For experiments, embryos at 8-cell stage were used after 20~22 hours in culture. After conventional (c-LAH) or partial laser assisted hatching, the embryos were further cultured in P-1 medium supplemented with 0.4% BSA for 3 days. To compare efficiency of complete and partial laser assisted hatching, hatching rate, hatching time and blastocyst diameter and zona pellucida thickness at hatching time were investigated. Embryos were examined every 12 hours. Blastocyst diameter and zona pellucida thickness at hatching time were measured with an ocular micrometer. RESULTS: Hatching rates of p-LAH group (84.2%) was significantly higher than that of control group (39.3%), but there was no difference between the p-LAH (84.2%) and c-LAH (91.2%). p-LAH group was hatched 12 hours earlier than control group, but hatched 12 hours later than c-LAH group. The diameter of blastocyst at hatching time of p-LAH group (113.1+/-6.4 micrometer) was smaller than that of control group (122.2+/-5.0 micrometer), but larger than that of c-LAH group (102.2+/-2.7 micrometer). Zona pellucida thickness at hatching time of p-LAH group (6.4+/-0.9 micrometer) was thicker than that of control group (4.5+/-1.5 micrometer), but thinner than that of c-LAH group (10.0+/-0.8 micrometer). CONCLUSION: These results suggest that p-LAH may maintains the cell arrangement of early embryos to ensure successful development and prevent precocious hatching of blastocyst when compare to c-LAH and conventional (acidic tyrode) AH. Thus, p-LAH may provide a valuable and effective AH technique for human ART program.

Impreovement in Endometrial Implantation of Humman Embryos with Assisted Hatching Using Micromanipulation in Intrauterine Embryo Transfer / 대한산부인과학회잡지

Although the fertilization rate exceeds to 80~90% with much progress in vitro fertilizaton and embyo transfer(IVF-ET) program, the prgnancy rate rmains at 20~30%, and the endometrial implantaion rate per embryo transferred at 10~15%. Recently, many attempts have been made to improve embrynic implantion after IVF-ET including serveral procedures of assisted hatching(AH) using micromanipulation, and pregnacies and births have been obtained after AH. This clinical study was performed to develop and estabilish AH as an effective procedure to improve embryonic implantioan in IVF-ET patients who had previous repeated failure of standard IVF-ET more than 2 times(Group R), were more than 37 years old(Group A), or had high basal serun FSH levels more than 15 mIU/ml(Group F). From January, 1995 to Februry, 1996, 132 cycles of AH using partial zona dissection(PZD) were performed in 104 infertile patients, and the outcomes of AH were analyzed according to pregnancy rate. The number of oocytes retrieved after controlled ovarian hyperstimulation(COH) was 9.9+/-7.1 in 71 cycles of 54 patients who had previous repeated failure more than two times(Group I: Group R,R+A,R+F, and R+A+F), 8.4+/-5.9 in 62 cycles of 46 patients whose age was more than 37 years old(Group II : Groups A, R+A, A+F, and R+A+F), and 8.7+/-6.5 in 49 cycles of 47 patients who had high basal serum FSH levels more than 15 mIU/ml(Group III:Groups F,R+F, A+F, and R+A+F). The number of embroys transferred after AH was 4.7 +/-1.8 in Group I, 4.2 +/-1.9 in Group II, and 4.2+/-2.0 in Froup III. The mean cumulative embryo score(CES) was 56.8+/-30.0 in Group I, 52.6+/-30.6 in Group II, and 52.6+/-29.9 in Group III. There were no significant differences in the numbers of oocytes rerieved and embryos transferred, and CES among 3 groups. The overall clinical pregnancy rate was 14.4%(19/132) per cycle and 18.3%(19/104) per patient. THe clinical pregnancy rate per cycle and per patient was 12.7%(9/71) and 16.7%(9/54) in Group I, 4.8% (3/62) and 6.5%(3/46) in Group II, and 26.5%(13/49) and 27.7%(13/47) in Group III, and there was a significant difference between Group II and Group III. In conclusion, AH of human embryos using micromanipulation might be promising for IVF-ET patients, especially with the past history of repeated failure, old age, and high basal serum FSH level and AH will provide a range of novel techiques which may dramatically improve the implanatation and pregnancy rates in IVF-ET program and contribute much to effective management of infertile couples.