The risk of poor ovarian response during repeat IVF

What are the incidence and risk factors for poor ovarian response (POR) during repeat IVF?

A retrospective analysis of 1224 consecutive patients who underwent at least two IVF stimulations in a single centre over a 6-year period. Risk factors from the initial treatment were assessed for association with POR during repeat IVF using logistic regression analysis. A simple, practical predictive model was constructed and evaluated for accuracy and calibration, based on the factors that demonstrated significant association with subsequent POR. POR during repeat IVF was defined as ≤3 retrieved oocytes or cancellation before retrieval following recruitment of ≤3 mature follicles.

The risk of POR during repeat IVF was approximately 11.5%. A higher POR risk during repeat IVF is associated with a reduced oocyte yield during the initial treatment (≤3 oocytes: odds ratio [OR] 14, 95% confidence interval [CI] 6.42-30.24; 4-9 oocytes: OR 4.13, 95% CI 2.00-8.54; 10-15 oocytes: OR 1) and low ovarian reserve (anti-Müllerian hormone [AMH] <5.4 pmol/l: OR 3.54, 95% CI 2.24-5.59; AMH 5.4-25 pmol/l: OR 1). Women with low ovarian reserve who experience POR during the initial IVF have the highest risk of suffering POR again during repeat IVF (57% within 1 year). Other groups, such as women with unexpected POR or expected poor responders with suboptimal ovarian response during the initial IVF, are also at risk of exhibiting POR during a subsequent treatment (28% within 1 year).

As there is a clear association between POR and lower live birth rates, this practical model may help manage patients' expectations during repeat IVF treatment.