Evaluation of Free Fluid in the Left Adnexa and Cervix
Clinical Significance
- The presence of free fluid in the left adnexa and cervix is highly concerning for ectopic pregnancy, especially when associated with a positive pregnancy test and no visible intrauterine pregnancy, according to the American College of Radiology 1, 2
- Ectopic pregnancies are located ipsilateral to the corpus luteum in 70-80% of cases, making left adnexal fluid potentially significant, as noted by the American College of Radiology 2
- More than a normal small amount of free fluid or echoes within the fluid is concerning for ectopic pregnancy, as reported by the American College of Radiology 2
Evaluation Algorithm
- Perform pregnancy test (β-hCG) immediately, and if positive, proceed with transvaginal ultrasound (TVUS) to look for intrauterine pregnancy, as recommended by the American College of Radiology 1, 2
- Assess fluid characteristics, including volume, with trace anechoic free fluid generally being normal, but larger amounts warranting further investigation, according to the American College of Radiology 2
Common Causes
- Ectopic pregnancy is the most likely cause with a positive pregnancy test and no visible IUP, as stated by the American College of Radiology 1, 2
- Ruptured ovarian cyst can cause sudden onset of pain with free fluid, as reported in the Annals of Emergency Medicine 4
- Pelvic inflammatory disease may present with free fluid and adnexal tenderness, according to the MMWR Recommendations and Reports 5
- Ovarian torsion may have associated free fluid and requires urgent evaluation, as noted by the American College of Radiology 3
Pitfalls to Avoid
- False reassurance from a small amount of free fluid, which doesn't exclude early or slowly developing pathology, as warned by the Annals of Emergency Medicine 6
- Misidentification of perinephric fat or fluid in stomach/bowel as free fluid, as cautioned by the Annals of Emergency Medicine 6
- Overlooking fluid in the suprapubic view due to posterior acoustic enhancement from bladder, as noted by the Annals of Emergency Medicine 6