In vitro fertilization-embryo transfer in patients with unexplained recurrent pregnancy loss

Area of Science:

• Reproductive Medicine
• Infertility Research
• Clinical Embryology

Background:

• Unexplained recurrent pregnancy loss (URPL) lacks precise empiric therapy.
• Assisted reproductive technology (ART) is sought by URPL patients with secondary infertility or advanced maternal age.
• Clinical outcomes of URPL patients undergoing in vitro fertilization-embryo transfer (IVF-ET) require further study.

Purpose of the Study:

• To elucidate the clinical outcomes of URPL patients undergoing IVF-ET.
• To identify factors influencing IVF-ET outcomes in URPL patients.
• To compare IVF-ET outcomes between URPL and tubal factor infertility (TFI) patients.

Main Methods:

• Retrospective cohort study of 312 infertile URPL patients (January 2012 - December 2015).
• Comparison of clinical outcomes between URPL patients and TFI patients.
• Analysis of factors affecting clinical outcomes in URPL patients.

Main Results:

• No significant differences in clinical pregnancy or live birth rates (LBR) in fresh embryo transfer (ET) cycles between URPL and TFI groups.
• URPL group showed lower LBR in frozen-thawed ET cycles (23.56% vs. 33.56%, P=0.047).
• Cumulative LBRs were not significantly different between groups (34.69% vs. 38.26%, P=0.368).
• Increased endometrial thickness (EMT) and retrieved oocytes were protective factors for clinical pregnancy in stimulated cycles.
• Increased retrieved oocytes, two-pronucleus rate, and EMT were protective factors for cumulative live birth outcomes.

Conclusions:

• Age-matched URPL and TFI patients exhibit similar IVF-ET clinical outcomes.
• Thicker endometrium and more retrieved oocytes enhance fresh transfer cycle pregnancy probability.
• Improved normal fertilization potential increases live birth possibility in URPL patients.