Objective To evaluate whether preovulatory intrauterine saline flushing, compared with a sham procedure, improves live birth in patients with unexplained infertility. Design A two-centre, triple-blind, parallel-group, superiority randomised controlled trial. Setting Two Canadian fertility clinics Population A total of 192 patients aged 18–37 years with unexplained infertility for at least 12 months. Methods Participants were randomised on the day of the luteinising hormone surge to receive either preovulatory intrauterine flushing with 20 mL of physiological saline (intervention) or a sham procedure consisting of 10 mL intravaginal saline (sham). Main Outcome Measures Live births (primary outcome) and pregnancies (secondary outcome) over one cycle of treatment. Results Ninety-six participants were assigned to each group, with no loss to follow up. Groups were comparable at baseline, including a mean age of 31.8 ±3.0 and 31.5 ± 3.3 years with 51 and 54% of primary infertility in the intervention and sham groups, respectively. Three live births occurred in each arm (relative risk [RR] 1.0; 95% confidence interval [CI] 0.2–4.8). One spontaneous abortion occurred in the sham group, with no difference between groups in pregnancy rates (RR 0.8; 95% CI 0.2–3.3). Pain during the procedure was more common in the intervention group (55% vs. 13%; p<0.001), although usually mild. No pelvic infections occurred, and severe pain was reported by only 1% (1/96) of participants in the intervention group. Conclusions Despite prior data suggesting uterine flushing as an effective treatment for unexplained infertility, this trial does not support its efficacy when performed with physiological saline.

Objective To identify phenotypes of pain in patients with endometriosis and to investigate their associations with predictors and quality of life (QoL). Design Population-based study. Setting A referral university center in Quebec City, Canada. Population or Sample A total of 352 patients aged 18‒50 years and diagnosed with endometriosis. Methods Latent class analysis (LCA) was used to identify pain phenotypes. To assess the associations, the three-step approach of LCA was applied. Main Outcome Measures Pain phenotypes, predictors of pain phenotypes, QoL. Results A total of 352 patients were included in the analyses. The diagnosis of endometriosis was either based on histology (N=135), imaging (N=106) or clinical presentation (N=111). The optimal model identified two distinct and homogeneous phenotypes of patients with endometriosis. The two groups had distinct clinical presentations, one with more severe and frequent pain symptoms and poorer quality of life (54%); the other with mild and less frequent pain symptoms (46%). Predictors of a high pain phenotype were a previous treatment failure, use of pain killers, a family history of endometriosis, a low annual family income, and pain comorbidities such as painful bladder, fibromyalgia, migraines, low back pain, irritable bowel syndrome, anxiety, and depression or mood disorders. The presence of endometrioma was predictive of the low pain phenotype. Phenotype membership was associated with distinct quality of life profiles (p<0.001). Conclusion Patients with endometriosis and pelvic pain can be grouped into two distinct and homogeneous phenotypes. Phenotypes membership correlates with quality of life and can be predicted with the patients’ characteristics. These findings will need to be validated in other populations and may inform the development of more specialized or personalized interventions based on the pain phenotypes.