Unexpected poor responder versus unexpected normal responder in the subsequent stimulation cycle, a cohort study

Area of Science:

• Reproductive Endocrinology
• In Vitro Fertilization (IVF)
• Ovarian Response Prediction

Background:

• Predicting ovarian response in subsequent IVF cycles is crucial for optimizing treatment strategies.
• Understanding unexpected responses can refine patient counseling and management.
• Previous poor ovarian response (POR) is a significant concern in assisted reproductive technology.

Purpose of the Study:

• To compare the likelihood of poor ovarian response (POR) in a second IVF stimulation cycle between women with an unexpected POR and those with an unexpected normal response in their first cycle.
• To identify factors influencing ovarian response in consecutive stimulation cycles.

Main Methods:

• A retrospective cohort study involving 9,408 women undergoing their first and second IVF stimulation cycles at a single center.
• Participants were categorized into four groups based on predicted (AMH/AFC) and actual ovarian response.
• Primary outcome was POR in the second cycle (oocyte number < 4), with adjustments for age, BMI, and infertility factors.

Main Results:

• Women with an unexpected POR in the first cycle had a significantly lower risk of POR in the second cycle (13% vs. 24%, adjusted OR: 0.52).
• These women also had a lower rate of no available embryo for transfer (12% vs. 21%) and higher rates of biochemical, clinical, and multiple pregnancies.
• Sensitivity analyses in younger women (≤35 years) confirmed these stable findings.

Conclusions:

• An unexpected poor ovarian response in the first IVF cycle is associated with a reduced risk of poor response in the subsequent cycle.
• This suggests that initial unexpected POR may not always predict future poor outcomes, offering a more optimistic outlook for some patients.
• These findings can inform personalized IVF treatment planning and patient expectations.