Pregnancy of unknown location

Dr Yusra Sheikh and Radswiki et al.

The term pregnancy of unknown location (PUL) is assigned when neither an intrauterine pregnancy (IUP) or an ectopic pregnancy is identified on transvaginal ultrasound in the context of a positive pregnancy test.

  • pelvic pain
  • vaginal bleeding
  • positive pregnancy test
  • serial beta-hCG: has an adjunct role in the diagnosis of ectopic pregnancy, and is useful in the follow-up of clinically-stable patients 
  • serum progesterone: lack of progesterone has been considered an indication of non-viability 3
    • <5 ng/mL is a good indicator of non-viability, however, larger values cannot exclude an ectopic pregnancy 4

These patients will present with a "normal" pelvic ultrasound, with no signs of an intrauterine pregnancy and a normal adnexa 5.

Since the most likely underlying diagnosis is non-viable intrauterine pregnancy 6, methotrexate and/or surgical intervention are not recommended in a hemodynamically-stable patient 6.

Thus, for the hemodynamically-stable patient, a short interval repeat ultrasound examination and quantitative beta-hCG level are generally appropriate 5,6.

A pregnancy of unknown location reflects four possibilities:

Article information

rID: 15322
System: Obstetrics
Synonyms or Alternate Spellings:
  • Pregnancy of unknown location (PUL)
  • Pregnancy of uncertain location (PUL)
  • Gestation of unknown location

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Cases and figures

  • Case 1
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