Impact of trigger protocol and embryo transfer type on IVF pregnancy outcomes: a single-center, retrospective, observational study

Background: Infertility, defined as the inability to conceive after 12 months of regular, unprotected intercourse, affects over 186 million people globally, with a significant burden in developing countries. Assisted reproductive technology (ART), particularly in vitro fertilization (IVF), has evolved as a key intervention for infertility, with advancements such as ovulation triggers playing a crucial role. This study investigates the effectiveness of single versus dual trigger methods between fresh and frozen embryo transfers and their impact on IVF outcomes. Methods: This observational study was conducted at Srushti Fertility Centre and Women’s Hospital from 2022 to 2023. A consecutive sampling of 140 participants undergoing ART was performed, categorizing them into Single Trigger (n=48) and Dual Trigger (n=92) groups. Key parameters such as age, hormonal levels (AMH, FSH, LH), endometrial thickness, and serum progesterone levels were measured and analyzed in relation to IVF outcomes. Results: The study found that optimal endometrial thickness (8-9 mm, p=0.031) and low progesterone levels (<0.5 ng/mL, p=0.003) were significantly associated with positive IVF outcomes. Fresh transfers with low progesterone levels (p=0.016) and dual trigger methods produced better embryo development. However, IVF outcomes did not differ significantly between fresh and frozen embryo transfers (p=0.276). Conclusions: The dual trigger method, especially with frozen transfers, enhances embryo quality and pregnancy rates. However, overall differences between frozen and fresh transfers were not statistically significant, emphasizing individualized hormonal management for better outcomes. This study highlights the importance of optimizing endometrial thickness and managing progesterone levels to improve pregnancy success in ART.