RESUMEN
PURPOSE: To determine the risk of multiple pregnancies (MP) following conversion of in vitro fertilization (IVF) cycles to intrauterine insemination (IUI) when a poor ovarian response (POR) is diagnosed during controlled ovarian stimulation (COS). METHODS: We undertook a retrospective study in our teaching hospital from January 2012 to December 2017. We included all IVF cycles with POR that were converted to IUI (<5 follicles ≥ 14 mm and peak estradiol level < 1000 pg/mL on trigger day). RESULTS: Overall, 205 IVF cycles that were converted to IUI in 128 patients were analyzed. Mean age was 34.1 ± 4.6 years, mean antral follicle count was 11 ± 5.3 and mean AMH was 1.8 ± 2.9 ng/L. The main causes of infertility were unexplained (41 %) (84/205) and diminished ovarian reserve (35 %) (72/205). Of all the cycles converted to IUI, 53 (26 %) had one mature follicle on trigger day, 56 (27 %) had 2, 56 (27 %) had 3, and 40 (20 %) had 4. The live birth rate (LBR) was 7.3 % (15/205), and the miscarriage rate was 28.6 % (6/21). There were 3 twin pregnancies, but no higher order pregnancies; the MP rate was 14.3 % (3/21). There was no significant difference in the MP rate between patients with 1-2 mature follicles and patients with 3-4 mature follicles (18.2 % vs 10 %, p = 0.99, respectively). CONCLUSION: In IVF cycles converted to IUI for poor response, the risk of MP is acceptable (14 %) with no higher order pregnancies, even with 3 or 4 follicles ≥14 mm on trigger day.