RESUMEN
OBJECTIVE: To compare the continuation of in vitro fertilization (IVF) with the conversion to intrauterine insemination (IUI) in cases of suboptimal ovarian response in Bologna-criteria poor responders. DESIGN: Retrospective and multicenter comparative study. SETTING: Three academic fertility centers and a fertility private clinic. PATIENT(S): Analysis of 7,176 initiated IVF cycles from January 2010 to January 2013. The 461 cycles with poor ovarian response (fewer than three follicles ≥16 mm at hCG trigger) in patients with poor response according to the Bologna criteria were included. INTERVENTION(S): Decision to pursue IVF (n = 184), convert to IUI (n = 141), or cancel cycle (n = 136) when only one or two follicles were recruited. MAIN OUTCOME MEASURE(S): Live birth, ultrasound pregnancy, and early pregnancy rates were compared depending on whether they resulted from IVF or IUI and were stratified according to patient age and the number of mature follicles at trigger. RESULT(S): Live birth rates were significantly higher for IVF patients compared with IUI conversion when two follicles were present (11.6% IVF vs. 1.6% IUI), especially for patients <40 years of age (13.1% IVF vs. 2% in IUI). In case of a monofollicular recruitment, the pregnancy outcomes were similar. CONCLUSION(S): A therapeutic strategy could therefore be to pursue IVF for women demonstrating two follicles and to convert to IUI for cycles with only one follicle if the sperm and tubal parameters are favorable.