Pregnancy of unknown location

Question 1

What is a pregnancy of unknown location?

Answer 1

In 40% of women with ectopic pregnancy, the diagnosis is NOT made on first attendance and
are labelled as having pregnancy of unknown location (PUL)

Definition: TVUSS shows an empty uterus with no evidence of an adnexal mass in a patient
with a positive pregnancy test
o Note: the definition is based on a TRANSVAGINAL ultrasound

Question 2

What are the potential diagnoses of PUL?

Answer 2

o Complete miscarriage
▪ Hence nothing seen on scan but serum results not returned to baseline yet

o Pregnancy
▪ May be too early to detect anything on TVUSS yet

o Ectopic
▪ Can be difficult to see on scan sometimes/may be too early

Question 3

What Ix do you do for PUL?

Answer 3

o Serial serum hCG
▪ Every 48 hours
▪ If dropping: failing pregnancy
▪ If increasing as expected: normal intrauterine pregnancy
▪ Lower rate of increase (usually approx. <53% increase over 48 hours or
plateau of level): suspicion of ectopic
o Serum progesterone
▪ Determines whether pregnancy failing or not
▪ If < 2, likely failing
o Endometrial biopsy may be helpful if hCG levels are static

Question 4

What is the management of PUL?

Answer 4

o Potential ectopics must be managed early to prevent rupture
o Small proportion of women remain persistent PULs → will likely need methotrexate