Influence of assisted hatching on pregnancy outcomes in women with poor ovarian response: An RCT.

Background: Advances in assisted reproductive technology have led to improved outcomes through various innovations. The embryo must hatch from its acellular glycoprotein-based outer layer, the zona pellucida, before it can be implanted. Assisted hatching (AH) is a technique proposed to enhance embryo implantation.

Objective: This study aimed to evaluate the efficacy of AH in improving pregnancy outcomes among women with poor ovarian response (POR) undergoing in vitro fertilization/intracytoplasmic sperm injection.

Materials and methods: A randomized controlled trial was conducted involving 170 women with POR (POSEIDON groups 3 and 4) undergoing in vitro fertilization/intracytoplasmic sperm injection at the Yazd Reproductive Sciences Institute, Yazd, Iran from December 2023-June 2024. Participants were randomly assigned to either the hatching group or the control group. Clinical pregnancy, chemical pregnancy, ongoing pregnancy, and miscarriage rates were compared between the 2 groups.

Results: No significant difference was observed between the hatching and control group in terms of chemical pregnancy (24.4% vs. 17.3%. p = 0.271), clinical pregnancy (23.1% vs. 14.8%, p = 0.183), ongoing pregnancy (16.7% vs. 11.1%, p = 0.310), and miscarriage rates (27.8% vs. 25.0%, p = 0.866). However, a significant difference was observed in the frozen embryo transfer subgroup, with the hatching group demonstrating significantly higher rates of ongoing and clinical pregnancies compared to the control group.

Conclusion: While AH did not demonstrate overall benefits in improving pregnancy outcomes in women with POR, it may enhance the chances of ongoing and clinical pregnancy in frozen embryo transfer cycles.