Pregnancy of unknown location


See ((Ectpoic Pregnancy))



Ultrasound does not definitively identified pregnancy location and up to 40% of women presenting for evaluation. 


It is estimated that between 8% and 10% of women attending for an ultrasound assessment in early pregnancy will be classified as having a PUL.


Pregnancy of unknown location (PUL) is the term used for a pregnancy where there is a positive pregnancy test but no pregnancy has been visualized using transvaginal ultrasonography.



This state is termed pregnancy of unknown location.



A persistent pregnancy of unknown location indicates that upon surveillance 1/3 of women will have serial hCG concentrations suggesting neither an ongoing viable gestation nor a spontaneous resolving pregnancy loss.


The true nature of the pregnancy can be an ongoing viable intrauterine pregnancy, a failed pregnancy, an ectopic pregnancy or rarely a persisting PUL.


In women with a pregnancy of unknown location, between 6% and 20% have an ectopic pregnancy.

Between 30% and 47% of women with pregnancy of unknown location are ultimately diagnosed with an ongoing intrauterine pregnancy, whereof the majority (50–70%) will be found to have failing pregnancies where the location is never confirmed.


Persisting PUL is where the hCG level does not spontaneously decline and no intrauterine or ectopic pregnancy is identified on follow-up transvaginal ultrasonography.


A persisting PUL is likely either a small ectopic pregnancy that has not been visualized, or a retained trophoblast in the endometrial cavity.


Treatment should only be considered when a potentially viable intrauterine pregnancy has been definitively excluded.


 A treated persistent PUL is defined as one managed medically.



PUL is generally managed with methotrexate, without confirmation of the location of the pregnancy such as by ultrasound, laparoscopy or uterine evacuation.


A resolved persistent PUL is defined as serum hCG reaching a non-pregnant value after expectant management, or after uterine evacuation without evidence of chorionic villi on histopathological examination.


A relatively low and unresolving level of serum hCG indicates the possibility of an hCG-secreting tumor.


Most women with a PUL are followed up with serum hCG measurements and repeat transvaginal sonogram examinations until a final diagnosis is confirmed.


Low-risk cases of PUL that appear to be failing pregnancies may be followed up with a urinary pregnancy test after two weeks.

Leave a Reply

Your email address will not be published. Required fields are marked *