Pain assessment in women with or without endometriosis during the IVF process: a prospective study

How does the typology and effect of pain vary between infertile patients with or without endometriosis during the different stages of the IVF process? A prospective, monocentric, observational cohort study was conducted at Lille University Hospital between November 2019 and June 2021. The study was proposed to all patients starting an IVF cycle. Pain assessment questionnaires using validated scales (about type of pain, without specific location), were completed by patients at key points during IVF: before starting treatment, at the end of stimulation and on the day of oocyte retrieval. A total of 278 patients were analysed: 73 patients with endometriosis and 205 without. At the start of the IVF process, patients with endometriosis had higher pain scores than disease-free women (mean numerical scale score 3.47 versus 1.12 [P < 0.0001]) and 17.81% of patients with endometriosis had neuropathic pain. For mental disorders before starting treatment, 22% of patients with endometriosis had suspected or confirmed depression, and 33% had anxiety compared with 8% and 20% in patients without endometriosis, respectively. During IVF, for patients without endometriosis, pain increased significantly between the baseline, the end of stimulation and on the day of retrieval (P ≤ 0.05). In patients with endometriosis, however, pain did not significantly vary during these times. Endometriosis is associated with higher pain scores, but no increase in pain was observed during IVF for these patients. It seems essential to screen and characterize pain phenotypes in all patients before starting treatment and during stimulation to improve pain management.