Defining thresholds for abnormal premature progesterone levels during ovarian stimulation for assisted reproduction technologies.

OBJECTIVE: To evaluate methodologies to establish abnormal progesterone (P) levels on the day of trigger for recommending freeze only cycles.

DESIGN: Threshold analysis and cost analysis.

SETTING: Private ART practice.

PATIENT(S): Fresh autologous ART.

INTERVENTIONS(S): None.

MAIN OUTCOME MEASURE(S): Live birth.

RESULT(S): Fourteen established statistical methodologies for generating clinical thresholds were evaluated. These methods were applied to 7,608 fresh ART transfer cycles to generate various P thresholds which ranged widely from 0.4 to 3.0 ng/mL. Lower thresholds ranged from 0.4 to 1 ng/mL and classified the majority of cycles as abnormal as well as required very large number needed to treat (NNT) to increase one live birth. Frozen embryo transfer was cost-effective when P was ≥1.5 ng/mL, with 12% of the population having an abnormal test result and an NNT of 13. Statistical and cost-effective thresholds clustered between 1.5 and 2.0 ng/mL.

CONCLUSION(S): Statistically significant thresholds for P were demonstrated as low as 0.4 ng/mL but resulted in a very large NNT to increase one live birth. A clinical benefit to a freeze-only approach was demonstrated above P thresholds ranging from 1.5 to 2.0 ng/dL. At these thresholds, elevated P has a demonstrable and clinically significant negative effect and captures a smaller percentage of the patient population at higher risk for fresh transfer failure, thus making freeze-only a cost-effective option.