title: Effect of assisted hatching on pregnancy outcomes: a systematic review and meta-analysis of randomized controlled trials.
abstract: Emerging evidence suggests that assisted hatching (AH) techniques may improve clinical pregnancy rates, particularly in poor prognosis patients; however, there still remains considerable uncertainty. We conducted a meta-analysis to verify the effect of AH on pregnancy outcomes. We searched for related studies published in PubMed, Web of Science, and Cochrane library databases from start dates to October 10, 2015. Totally, 36 randomized controlled trials with 6459 participants were included. Summary odds ratios (ORs) with 95% confidence intervals (CIs) for whether by AH or not were estimated. We found a significant increase in clinical pregnancy (OR = 1.16, 95% CI = 1.00-1.36, I(2) = 48.3%) and multiple pregnancy rates (OR = 1.50, 95% CI = 1.11-2.01, I(2) = 44.0%) with AH when compared to the control. Numerous subgroup analyses stratified by hatching method, conception mode, extent of AH, embryos transfer status, and previous failure history were also carried out. Interestingly, significant results of clinical pregnancy as well as multiple pregnancy rates were observed among women who received intracytoplasmic sperm injection, and who received AH which the zona were completely removed. In summary, this meta-analysis supports that AH was associated with an increased chance of achieving clinical pregnancy and multiple pregnancy. Whether AH significantly changes live birth and miscarriage rates needs further investigations.
authors: Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors: Da
authors: D
authors: Li
authors: Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors: Da-Lei
authors: DL
authors: Yang
authors: Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors: Jing
authors: J
authors: An
authors: Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors: Jiao
authors: J
authors: Jiao
authors: Department of Medicine, Brigham and Women's Hospital, Harvard Institutes of Medicine, Harvard Medical School, Boston, MA 02115, USA.
authors: Yi-Ming
authors: YM
authors: Zhou
authors: Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors: Qi-Jun
authors: QJ
authors: Wu
authors: Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors: Xiu-Xia
authors: XX
authors: Wang
mesh_terms: D000022:Abortion, Spontaneous; D000328:Adult; D010064:Embryo Implantation; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D050498:Live Birth; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D016032:Randomized Controlled Trials as Topic; D020554:Sperm Injections, Intracytoplasmic; D015044:Zona Pellucida / Q000502:physiology