Laser-assisted Zona Thinning Research Articles

Thinning or Opening: A Randomized Sibling-Embryo Pilot Trial on the Efficacy of Two Laser-Assisted Hatching Modes During the Extended Culture of Highly Fragmented Cleavage Embryos.

A randomized sibling-embryo pilot trial investigated whether two ways of laser-assisted hatching result in different blastulation and clinical outcomes after extended in vitro culture process of highly fragmented day-3 cleavage embryos. From 92 couples, a total of 315 highly fragmented day-3 embryos (the fragmentation >25%) were recruited and randomized into laser-assisted zona thinning (LAT, n=157) and opening (LAO, n=158) groups, and then underwent a blastocyst culture in vitro. The main endpoint measurements including blastocyst formation and grading as well as the clinical pregnancy after blastocyst transfer were obtained during the treatment procedure of in vitro fertilization and embryo transfer, and then analyzed with generalized estimating equation (GEE) and/or time-to blastocyst analysis models. A total of 166 day-3 embryos developed into blastocyst stage (52.70%), of which 97 were viable blastocysts (30.79%), and 42 top-quality ones (13.33%). LAT did not have any inferior or superior to LAO in the endpoints of either total, viable, top-quality or hatched blastocyst formation, with the ORs (95%CI) from GEE model as 0.89 (0.55-1.45), 0.71 (0.42-1.21), 1.12 (0.56-2.25) and 0.68 (0.42-1.12) respectively for LAT treatment. And the time-to-blastocyst analysis showed a similar result. Additionally, no difference in clinical outcomes after blastocyst transfer was found between the two groups. The author concluded that when applying the LAHs during the extended culture of highly fragmented embryos, both LAT and LAO can generate a promising clinical outcome, and the LAT operation be equivalent to the LAO. Future well-designed, multiple-center, larger-sample investigations are required to ascertain above conclusion.

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 & 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 & 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 < 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 >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 > 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.

Laser-assisted hatching and clinical outcomes in frozen-thawed cleavage-embryo transfers of patients with previous repeated failure.

Assisted hatching (AH) is initially developed to provide an artificial manipulation of the zona pellucida (ZP) to help embryos hatch and improve the capacity of the embryos to implant. However, these effects remain unclear and controversial because of variation in patient characteristics, and it is critical to ascertain the indications for AH and to identify those patients who might benefit from AH. Here, this study aimed to assess the effect of laser-assisted zona thinning hatching technology (LAH) during the frozen-thawed D3 embryos on pregnancy outcomes in patients with previous repeated failures in vitro fertilization-embryo transfer (IVF-ET). To the best of our knowledge, these relationships have not been previously investigated. A retrospective cohort analysis was carried out. Infertility patients with previous repeated failure who underwent assisted reproductive therapy at our in vitro fertilization (IVF) center from May 2014 to May 2016 were enrolled. A total of 415 cleavage FET cycles (225 in the LAH group and 190 in the control group) were analyzed. Clinical outcomes including clinical pregnancy, implantation, live birth, miscarriage, and multiple gestation rates after transfer were compared between the LAH and control groups. The clinical pregnancy (49.3% versus 38.9%) and implantation rates (31.2% versus 24.6%) were significantly higher for the LAH group than the control group (P < 0.05). The live birth (44.8% versus 35.8%), multiple pregnancy (32.4% versus 31.0%), preterm birth (22.8% versus 17.1%), miscarriage (7.2% versus 5.4%), and ectopic rates (1.9% versus 0%) did not differ significantly between the two groups (P > 0.05). This study showed that LAH via zona pellucida (ZP) thinning significantly improves clinical outcomes, particularly clinical pregnancy and implantation rates, associated with FET cycles among patients with previous repeated failure.

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

ObjectiveThis 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.MethodsEight-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.ResultsIn 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).ConclusionThese results show that multi-area LAZT resulted in significantly improved pregnancy outcomes in human 8-cell embryos compared to controls.

Effect of laser-assisted zona thinning, during assisted reproduction, on pregnancy outcome in women with endometriosis: randomized controlled trial.

To compare the ICSI-ET outcomes in patients with endometriosis with or without laser-assisted zona pellucida thinning. Randomized controlled trial. The study was conducted in the Obstetrics & Gynecology Department, Cairo University hospital, and two private IVF centers in Cairo & Beni-Suif from July 2015 to January 2017 upon infertile and known endometriosis patients who planned to do ICSI-ET. Before randomization, all patients received the same ovarian stimulation preparation, oocyte retrieval procedures, and the same intracytoplasmic sperm injection procedures. After randomization, laser-assisted hatching was performed only for embryos of 158 patients, while the other group (n=150) no laser-assisted hatching was made. The verification of pregnancy was achieved by the serum hCG concentration 14days after the embryo transfer, and the clinical pregnancy was confirmed 2weeks later by the presence of gestational sac with pulsating fetal pole on vaginal ultrasonography. The main outcome measures were the clinical pregnancy rate and the clinical implantation rate. Both groups were comparable with regard their baseline characteristics, baseline hormonal profile, the ovarian stimulation characteristics, and the ovulation characteristics. The mean number of embryos developed per patient and the mean transferred number of embryos per patient were comparable between groups (p value>0.05). The implantation rate was significantly higher (p value 0.002) in the study group than the control group with an odds ratio of 1.86 (CI 95% 1.24-2.80) and NNT 13.81 (CI 95% 8.35-39.94). The clinical pregnancy rate, was significantly (p value 0.022) higher in the study group than in the control group with an odds ratio of 1.79 (CI 95% 1.05-3.06) and NNT 9.57 (CI 95% 5.03-98.99). That laser-assisted hatching by thinning of the zona pellucida may be a suitable method to improve the ICSI-ET outcomes, in term of the implantation and the pregnancy rates, in cases of endometriosis. Pan African Clinical Trials Registry (PACTR), http://www.pactr.org/ATMWeb/appmanager/atm/atmregistry?dar=true&tNo=PACTR201502001022393 , PACTR201602001467322.

Effect of laser-assisted multi-point zona thinning on development and hatching of cleavage embryos in mice.

ObjectiveThis study aimed to examine the effect of laser-assisted zona thinning (LAZT) at one or four-points on the blastocyst formation and hatching process in mice with respect to female age.MethodsEight-cell or morula embryos collected from superovulated C57BL female mice with different ages (6-11 and 28-31 weeks) were treated with LAZT at one-point (LAZT1) or four-points (LAZT4). The zona pellucida was thinned to more than 70% of its initial thickness by making two holes of 15-20 µm.ResultsIn the young mice, LAZT resulted in a significant increase in early hatching and hatching rates compared to the control group (p<0.05). However, in the old mice, LAZT significantly increased blastocyst formation as well as early hatching and hatching compared to the controls (p<0.05). These effects were more remarkable in LAZT4 than in LAZT1 and in aged mice than in young ones.ConclusionThese results show that multi-point LAZT leads to a significant improvement of blastocyst formation and hatching in mice compared to controls.

The effect of modified quarter laser-assisted zona thinning on the implantation rate per embryo in frozen/vitrified-thawed/warmed embryo transfer cycles: a prospective randomized controlled trial

Freezing/vitrifying and thawing/warming of embryos may impair the successful hatching process of the embryo out of its zona pellucida (ZP) and its following implantation into the uterus. Theoretically, assisted hatching (AH) may facilitate the hatching process and subsequently increase implantation rates (IRs). In this prospective randomized controlled trial (RCT), the hypothesis was tested that the IR per embryo transferred is higher after transfer (ET) of frozen/vitrified-thawed/warmed embryos with thinned ZP after AH by modified quarter laser-assisted zona thinning (mQLAZT) when compared with ET of frozen/vitrified-thawed/warmed embryos without mQLAZT. Patients with frozen/vitrified embryos were randomized at the time of thawing/warming to a study group (with mQLAZT) or a control group (without mQLAZT). After thawing/warming, embryos were kept in culture for 24h, and mQLAZT was performed prior to ET. A total of 647 thawing cycles were randomized to either the mQLAZT group (n = 324) or the control group (n = 323). Reproductive outcome data were available for 302 cycles in the mQLAZT group and 317 cycles in the control group. Transfer could be performed in 73.5% and in 71.9% of the thawing/warming cycles in the mQLAZT group and the control group (P = 0.78), respectively. No significant differences were observed between the mQLAZT group and the control group for the IR [13.3%; 15.6%; rate ratio 0.85; 95% confidence interval (CI), 0.596-1.224], the ongoing IR (10.5 and 13.5%, P = 0.25) and the live birth rate [10.5%;13.3%; rate ratio 0.79; (95% CI), 0.530-1.189] per embryo transferred. In this RCT, mQLAZT did not improve the IR per embryo transferred in frozen/vitrified-thawed/warmed embryo transfer cycles. ClinicalTrials.govID NCT00593775.

Laser assisted zona thinning technique has no beneficial effect on the ART outcomes of two different maternal age groups

Laser assisted zona thinning is a technique used for facilitating embryo's hatching process and is commonly used for the embryos of poor prognosis patients with advanced maternal age, repeated implantation failures, poor embryo quality or thick zona pellucida. The aim of this study was to investigate the effect of zona thinning on both good or poor prognosis patients of two different age groups. We investigated two different age groups (group 1: <35years and group 2: ≥35years ) and compared the effect of assisted zona thinning (groups 1A and 2A) versus not-thinned controls (groups 1B and 2B) in both groups. The clinical pregnancy rates were 57% and 56% in groups 1A and 1B (p = 0.86), 43% and 38% in groups 2A and 2B (p = 0.59) respectively. Our results suggest that laser assisted zona thinning of day 3 embryos has no beneficial effect on clinical pregnancy and implantation outcomes.

Higher Implantation Rate Using Modified Quarter Laser-Assisted Zona Thinning in Repeated Implantation Failure

Background/Aims: Some embryo implantation problems in patients with recurrent implantation failure may be explained by the inability of the embryo to hatch out of its zona pellucida. In this case-control study, a study group which had received modified quarter laser-assisted zona thinning (mQLAZT) was compared with a control group which had not received mQLAZT with respect to reproductive outcome. Methods: Cycles from patients with a 4th fresh embryo transfer (ET) after 3 previously failed ET cycles (no β-hCG detected) were included. Cases (group A, n = 53) included ET cycles from patients who received a 4th ET with fresh embryos after mQLAZT. Controls (group B, n = 86) included ET cycles from patients who had a 4th ET without mQLAZT. The clinical implantation rate and live birth rate per embryo transferred were measured. Results: The clinical implantation rate with positive fetal heart beat per embryo transferred was significantly higher (p = 0.035) in group A (22/107 or 21%) than in group B (18/166 or 11%). Conclusion: The data of this case-control study suggest that mQLAZT can be effective in the treatment of patients with recurrent implantation failure, but need to be confirmed by randomized trials.

Effect of modified quarter laser-assisted zona thinning (mQLAZT) on pregnancy and implantations rates in cryopreserved embryos: a prospective randomized controlled trial

OBJECTIVE: Freezing/thawing cycles can impair the successful hatching process. The hypothesis was tested that the clinical implantation rate (CIR) per embryo transferred and the clinical pregnancy rate (CPR) per embryo transfer (ET) is higher after ET of frozen-thawed embryos with thinned zona pellucida (ZP) after mQLAZT when compared to ET of frozen-thawed embryos without mQZLAT.

Conjoined twins in a trichorionic quadruplet pregnancy after intracytoplasmic sperm injection and quarter laser-assisted zona thinning

To describe the occurrence and management of conjoined twins (CTs) in a trichorionic quadruplet pregnancy after the transfer of three embryos obtained by intracytoplasmic sperm injection (ICSI) that had undergone assisted zona hatching (AZH) using a noncontact laser. Case report. Private and public IVF centers. A 38-year-old nulliparous woman. IVF, diagnosis by two-dimensional, three-dimensional, and four-dimensional ultrasound, selective termination at 12 weeks gestation. Clinical follow-up and delivery. After diagnosis, counselling, and selective termination, the subsequent prenatal course was uneventful, and two healthy boys were delivered by elective cesarean section at 38 weeks gestation. Monozygotic twinning (MZT) and CTs could complicate multifetal pregnancies obtained by assisted reproduction techniques. The relationship between CTs, IVF, and AZH should be better studied to fully understand the mechanisms that lead to MZT (with the possible role of AZH) and CTs in MZT, in particular. Three-dimensional and four-dimensional ultrasound improve prenatal assessment of the condition. Selective embryo reduction is a safe procedure for the management of these pregnancies.