Ultrasonography and β-hCG thumb|upright=1.55|Algorithm of the management of a pregnancy of unknown location, that is, a positive pregnancy test but no pregnancy is found on transvaginal ultrasonography. If serum hCG at 0 hours is more than 1000 IU/L and there is no history suggestive of complete miscarriage, the ultrasonography should be repeated as soon as possible.
Ultrasonography and β-hCG thumb|upright=1.55|Algorithm of the management of a pregnancy of unknown location, that is, a positive pregnancy test but no pregnancy is found on transvaginal ultrasonography. If serum hCG at 0 hours is more than 1000 IU/L and there is no history suggestive of complete miscarriage, the ultrasonography should be repeated as soon as possible