Pipelle Endometrial Sampling With a Full Bladder Compared With Standard Care: A Randomized Controlled Trial.

OBJECTIVE: To compare insertion failure rates for Pipelle endometrial sampling with a full bladder compared with the standard process (not taking into account bladder status) without cervical manipulation.

METHODS: A single-masked randomized trial was conducted in a single tertiary care center from July 2021 to January 2022. Two hundred fourteen participants aged 18 years or older who were scheduled for outpatient Pipelle endometrial sampling were randomized: 107 each to having a full bladder (by oral water intake) or standard process (without delayed sampling and bladder status not taken into account). Women with known cervical stenosis, gynecologic malignancy, uterine anomalies, leiomyoma distorting the uterine cavity, acute cervicitis, urge bladder dysfunction, intense anxiety, need for anesthesia or analgesic before the procedure, positive pregnancy test, or previous failed office endometrial sampling were excluded. The primary outcome was the insertion failure rate of endometrial sampling at first attempt. Secondary outcomes were pain during procedure, satisfaction score, analgesia use, procedure duration, and need for cervical manipulation. Factoring in a baseline insertion failure rate of 30.0%, relative risk of 0.45, α of 0.05, 80.0% power, and a dropout rate of 10.0%, we needed 107 participants in each arm.

RESULTS: The insertion failure rate was significantly lower in the full bladder group compared with standard process: 25 of 107 (23.4%) compared with 45 of 107 (42.1%) (relative risk 0.56, 95% CI, 0.37-0.84; number needed to treat to benefit 6.0, 95% CI, 3.20-15.70). Pain score (median) during the procedure (interquartile range) was 4 (3-6) compared with 5 (3-8) (P=.004); patient satisfaction score was 8 (7-9) compared with 7 (4-8) (P<.001); and mean±SD procedure duration was 3.0±2.4 compared with 4.7±2.9 minutes (P<.001) for the full bladder and standard process arm, respectively. Other secondary outcomes of cervical laceration, analgesia use, and adequacy of endometrial tissue for histopathologic assessment were not significantly different between groups.

CONCLUSION: Pipelle endometrial sampling with a full bladder reduces the initial insertion failure rate, procedure-related pain, and duration of sampling and increases patient satisfaction compared with the standard process.

CLINICAL TRIAL REGISTRATION: ISRCTN, ISRCTN33938192.