First Trimester Pelvic Pain



First Trimester Pelvic Pain


Roya Sohaey, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Hemorrhagic Cyst


  • Corpus Luteum Cyst


  • Ectopic Pregnancy


Less Common



  • Adnexal Torsion


  • Appendicitis


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • First rule out ectopic pregnancy (EP)



    • Is there an intrauterine pregnancy (IUP)?



      • Presence of IUP best evidence against EP


      • Heterotopic ectopics are rare


    • Is the human chorionic gonadotropin (hCG) level high enough to see an IUP?



      • Should see IUP if hCG levels are > 2000 mIU/mL IRP (international reference preparation)


    • Lack of IUP at low hCG levels does not rule out EP



      • EP are not normal pregnancies and may have lower hCG levels


    • Look for blood in cul-de-sac


    • Look for an adnexal mass



      • EP itself or a hematoma


      • Look for EP on same side as the corpus luteum


  • Evaluate ovary on side of pain



    • Is the ovary enlarged?



      • Consider torsion


    • Is there a mass or mass-like lesion?



      • Characterize mass wall


      • Evaluate internal morphology


    • Doppler ultrasound



      • Variable findings with torsion


      • Compare with other ovary


      • Peripheral flow in EP (“ring of fire”) and ovarian cysts


      • Internal flow in neoplasm


  • Rule out other causes for pain



    • Gastrointestinal



      • Compression ultrasound for appendicitis


      • Inflamed bowel


    • Genitourinary



      • Hydronephrosis


      • Ureteral calculi


      • Pyelonephritis


Helpful Clues for Common Diagnoses



  • Hemorrhagic Cyst



    • Usually from hemorrhage into a corpus luteum


    • Acute and subacute findings



      • Reticular lace-like pattern


      • Fibrin strands not true septations


      • Retracting blood clot


    • Findings on follow-up



      • Fluid-fluid level


      • Anechoic cyst


    • Mass should resolve completely with time



      • 6 week follow-up recommended


    • Role of Doppler



      • No internal flow


      • Rule out associated torsion


  • Corpus Luteum Cyst



    • Abbreviated CL


    • Variable wall appearance



      • Thick, hyperechoic wall most common


      • Thin wall if large cyst


    • Variable internal echoes



      • Anechoic


      • Complex if hemorrhagic


      • Solid appearing if thick wall and no fluid


    • Doppler findings



      • Low resistive vascular flow in cyst wall


      • No internal flow


    • Rule out associated torsion


  • Ectopic Pregnancy



    • Uterine findings



      • Thin or thick endometrial cavity


      • “Pseudogestational sac” from blood in endometrial cavity


      • Endometrial cysts can mimic early IUP


      • Rare heterotopic pregnancy (IUP + EP)


    • Variable adnexal findings with tubal EP



      • Tubal distention or hematoma


      • Tubal gestational sac separate from ovary


      • EP on same side as CL in 85%


    • Doppler findings



      • Low resistive, high velocity flow


      • “Ring of fire”


    • Peritoneal blood



      • Echogenic fluid in cul-de-sac


      • Look higher up for abdominal blood


    • Unusual EP locations



      • Interstitial/cornual


      • Cervical


      • Ovarian


      • Abdominal



Helpful Clues for Less Common Diagnoses

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Aug 10, 2016 | Posted by in OBSTETRICS | Comments Off on First Trimester Pelvic Pain

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