IVF for unexplained subfertility; whom should we treat?

Area of Science:

• Reproductive Medicine and Endocrinology
• Infertility and Assisted Reproductive Technologies

Background:

• Clinical indications for in vitro fertilization (IVF) have expanded to include unexplained subfertility.
• Evidence from randomized controlled trials supporting IVF effectiveness in unexplained subfertility is limited.

Purpose of the Study:

• To compare ongoing pregnancy chances between IVF and expectant management for couples with unexplained subfertility.
• To identify factors influencing IVF effectiveness in this patient population.

Main Methods:

• A comparative study utilizing registry data for IVF (n=40,921) and prospective/retrospective cohorts for expectant management (n=5,850).
• Couples were matched based on characteristics to control for confounding factors.
• A Cox proportional hazards model estimated individualized 1-year conception chances, with ongoing pregnancy defined as reaching at least 12 weeks gestation.

Main Results:

• The adjusted 1-year conception chance was 47.9% with IVF versus 26.1% with expectant management, an absolute difference of 21.8% favoring IVF.
• IVF effectiveness was influenced by female age, duration of subfertility, and previous pregnancy history.
• IVF showed significant benefit for women under 40, but effectiveness declined for women over 34; it was less effective for women over 40 and in cases of short secondary subfertility with high natural conception potential.

Conclusions:

• In vitro fertilization (IVF) is associated with higher conception rates than expectant management for couples with unexplained subfertility, particularly for women under 40.
• Selective use of IVF based on individual couple characteristics and potential gain compared to expectant management is recommended.
• Findings support evidence-based counseling and shared decision-making for couples with unexplained subfertility.