Direct Warming Frozen Embryo Transfer Outcomes in Assisted Reproductive Technology

The goal of this clinical trial is to evaluate whether the direct warming method for frozen embryo transfers (FET) can improve live birth and pregnancy outcomes in women aged 18-45 undergoing IVF treatments. The main questions it aims to answer are: * Does the direct warming method achieve a similar or higher clinical success rate for FET compared to the conventional multi-step method? * Is the direct warming method more cost-effective than the conventional method? Researchers will compare the direct warming method to the conventional multi-step method to see if the former leads to better pregnancy outcomes and reduced procedural time. Participants will: * Undergo either the one-step or conventional embryo thawing procedure. * Complete standard clinical follow-ups for pregnancy, including ultrasound scans and pregnancy tests.