Modified natural cycle IVF versus conventional stimulation in advanced-age Bologna poor responders

Research question: Do ongoing pregnancy rates (OPR) differ between modified natural cycle IVF (MNC-IVF) and conventional high-dose ovarian stimulation (HDOS) in advanced-age Bologna poor responders? Design: This was a retrospective cohort study including patients with poor ovarian response (POR) attending a tertiary referral university hospital from 1 January 2011 to 1 March 2017 All women who fulfilled the Bologna criteria for POR and aged >= 40 years who underwent their first intracytoplasmic sperm injection (ICSI) cycle in the study centre were included. Results: In total, 476 advanced-age Bologna poor responder patients were included in the study: 189 in the MNC-IVF group and 287 in the HDOS group. OPR per patient were significantly lower in the MNC-IVF group (5/189, 2.6%) compared with the HDOS group (29/287, 10.1%) (P = 0.002). However, after adjustment for relevant confounders (number of oocytes and presence of at least one top-quality embryo), the multivariate logistic regression analysis showed that the type of treatment strategy (HDOS versus MNC-IVF) was not significantly associated with OPR (odds ratio 2.56, 95% confidence interval 0.9-76). Conclusions: In advanced-age Bologna poor responders, MNC-IVF, which is a more patient-friendly approach, could be a reasonable alternative in this difficult-to-treat group of women.