A 28-year-old woman presents with severe lower abdominal pain and vaginal bleeding 6 weeks after insertion of a copper T380A IUCD. On examination, the cervix appears normal and the uterus is tender. The IUCD threads are not visible in the cervical canal. Which investigation is most appropriate to confirm the suspected diagnosis?

Explanation

## Clinical Scenario Analysis The patient presents with acute abdominal pain, vaginal bleeding, and **missing IUCD threads** 6 weeks post-insertion. This constellation of findings is highly suspicious for **uterine perforation** — a serious complication of IUCD insertion. ## Investigation of Choice: Transvaginal Ultrasound **Key Point:** Transvaginal ultrasound (TVS) is the **first-line imaging modality** to diagnose IUCD perforation and locate a displaced IUCD. ### Why TVS is Superior | Feature | TVS | HSG | Diagnostic Laparoscopy | |---------|-----|-----|------------------------| | **Sensitivity for perforation** | 90–95% | 70–80% | 100% | | **Can locate IUCD position** | Yes (intra/extra-uterine) | Limited | Yes, but invasive | | **Non-invasive** | Yes | Yes | No | | **Real-time visualization** | Yes | Static images | Yes, but requires GA | | **Cost & availability** | Low, widely available | Moderate | High, requires OR | | **First-line in acute setting** | **Yes** | No | No | **High-Yield:** TVS can definitively show: - Absence of IUCD in the uterine cavity - Free IUCD in the peritoneal cavity (if perforation has occurred) - Uterine wall defect - Associated hemoperitoneum ## Clinical Pearl **Missing threads + acute pain = perforation until proven otherwise.** TVS should be done **immediately**; if perforation is confirmed, the patient requires **urgent laparoscopic or open retrieval** of the IUCD to prevent bowel injury, adhesions, and chronic pelvic pain. ## Why Other Investigations Are Not First-Line See **whyEachDistractorIsWrong** section below. [cite:Park 26e Ch 18]