Comparison of miscarriage rates in low prognosis patients according to the POSEIDON criteria

Objective: The POSEIDON criteria stratified patients with poor ovarian response into four subgroups with exclusive characteristics and assisted reproductive technology success rates. However, limited studies focused on miscarriage in the POSEIDON population. This study aimed to explore whether the miscarriage rate different among low prognosis patients according to POSEIDON criteria. Materials and methods: This is a retrospective observational study. All clinical pregnancies achieved after in vitro fertilization or intracytoplasmic sperm injection treatment between January 1998 and April 2021 were analyzed. The primary outcome was miscarriage, defined as the pregnancy loss before 20 weeks of gestation age. Miscarriage rate was estimated per clinical pregnancy and gestational sac. Results: A total of 1222 clinical pregnancies from 1088 POSEIDON patients met the inclusion criteria. The miscarriage rates per clinical pregnancy in each POSEIDON subgroup were as follows: Group 1: 11.7 %, Group 2: 26.5 %, Group 3: 20.9 %, and Group 4: 37.5 %. The miscarriage rate per gestational sac showed a similar trend as the clinical miscarriage rate. Multivariate regression analysis showed that advanced maternal age is an independent factor for miscarriage (Group 2 vs. 1: OR 2.476; Group 4 vs. 3: OR 2.252). Patients with diminished ovarian reserve (DOR) have higher miscarriage risks but without significance (Group 3 vs. 1: OR 1.322; Group 4 vs. 2: OR 1.202). Conclusion: Miscarriage rates differed among low prognosis patients according to the POSEIDON criteria. Age remains a determined risk for miscarriage. DOR might be a potential factor for miscarriage, but it didn't account for a significant impact in POSEIDON patients.