Intrauterine insemination cycles: prediction of success and thresholds for poor prognosis and futile care

Purpose: We aimed to define intrauterine insemination (IUI) cycle characteristics associated with viable birth, identify thresholds below which IUI treatments are consistent with very poor prognosis and futile care, and develop a nomogram for individualized application.

Methods: This retrospective cohort study evaluated couples using fresh partner ejaculate for IUI from January 2005 to September 2017. Variables included female age, semen characteristics, and ovarian stimulation type. Using cycle-level data, we evaluated the association of these characteristics with the probability of viable birth by fitting generalized regression models for a binary outcome with a logit link function, using generalized estimating equation methodology to account for the correlation between cycles involving the same patient.

Results: The cohort consisted of 1117 women with 2912 IUI cycles; viable birth was achieved in 275 (9.4%) cycles. Futile care (viable birth rate < 1%) was identified for women age > 43, regardless of stimulation type or inseminate motility (IM). Very poor prognosis (viable birth rate < 5%) was identified for women using oral medications or Clomid plus gonadotropins who were (1) age < 35 with IM < 49%, (2) age 35-37 with IM < 56%, or (3) age ≥ 38, and (4) women age ≥ 38 using gonadotropins only with IM < 60%. A clinical prediction model and nomogram was developed with an optimism-corrected c-statistic of 0.611.

Conclusions: The present study highlights the impact of multiple clinical factors on IUI success, identifies criteria consistent with very poor prognosis and futile care, and provides a nomogram to individualize counseling regarding the probability of a viable birth.