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

OBJECTIVE: To compare the ICSI-ET outcomes in patients with endometriosis with or without laser-assisted zona pellucida thinning.

DESIGN: Randomized controlled trial.

SETTING: 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.

INTERVENTIONS: 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 14 days after the embryo transfer, and the clinical pregnancy was confirmed 2 weeks later by the presence of gestational sac with pulsating fetal pole on vaginal ultrasonography.

MEASUREMENTS: The main outcome measures were the clinical pregnancy rate and the clinical implantation rate.

MAIN RESULTS: 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).

CONCLUSION: 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.

CLINICAL TRIAL REGISTRATION: Pan African Clinical Trials Registry (PACTR), https://www.pactr.org/ATMWeb/appmanager/atm/atmregistry?dar=true&tNo=PACTR201502001022393 , PACTR201602001467322.