Pregnancy Of Unknown
Location (PUL)
Dr Kamel Elbadry
MD (Sheffield University), FRCOG
Consultant Obstetrician and
Gynaecologist
●The term PUL is used whenever there is no
sign of either intra or extrauterine
pregnancy or retained products of
conception on transvaginal ultrasound
● A pregnancy site will not be visualised in
8-10% of early pregnancy scan in EPAU,
up to 31% in other units
Assessment
Whenever a woman presents with a positive
pregnancy test but no evidence of
pregnancy on TVS, clinical assessment
and serum B hCG should be carried out.
hCG and Ultrasound:
Using a discriminatory zone of hCG has
been widely evaluated.
An intrauterine pregnancy should be visible
on ultrasound if hCG ranges from 10002400 iu/l
In multiple pregnancy, hCG levels should be
interpreted with caution as they are little higher,
requiring an extra 3 days for the sacs to be
visible.
If hCG level above the discriminatory level with
no intrauterine gestational sac on ultrasound.
Determine whether the pregnancy is ectopic
The diagnosis of ectopic pregnancy should
be based on the identification of an
extrauterine sac, and indirect signs such
as a complex adnexal mass or fluid
collection rather than empty uterus on
scan.
The combination of the above scan
findings has a positive predictive value of
93.5%-100% for diagnosing ectopic.
Trans-vaginal colour Doppler has not been
shown to increase the detection rates of
ectopic when compared with 2D
ultrasound but may be useful in showing
enhanced trophoblastic flow.
The discriminatory level of each unit should
be based on :
hCG assay technique in use
Quality of ultrasound equipment
Operator experience
Progesterone:
Serum progesterone levels are elevated,
indicating the viability of corpus luteum,
but decrease if the pregnancy fails.
Progesterone level < 25 nmol/l, associated
with nonviable pregnancy (viable in 0.3%)
Progesterone < 20 nmol/l predicts failing
pregnancy with a positive prediction value
> 95%
Levels > 25 nmol/l are associated with
pregnancies.
Levels > 60 nmol/l are strongly associated
with intrauterine pregnancy (2.6% ectopic)
hCG pattern after 48 hours:
● Rise of hCG by 66%, predicts an
intrauterine pregnancy (predictive value
96.5%)
● Fall of hCG by at least 15%, most likely
outcome failing pregnancy
When the rise or fall in hCG is suboptimal,
the most likely diagnosis is ectopic.
Management of PUL
Conservative management:
According to the Association of Early
Pregnancy Units guidelines, if no
intrauterine or ectopic pregnancy or
retained products of conception are seen
on TVS and the woman is asymptomatic
she can be managed conservatively.
Expectant management of PUL has been
shown to be safe and to reduce the need
for unnecessary surgical intervention and
is not associated with any serious adverse
outcomes.
Unfortunately, multiple visits to EPAU are
necessary before diagnosis can be made.
Clinical outcome of PUL:
1- Failing PUL (44-69%)
2- Intrauterine pregnancy
3- Ectopic pregnancy
4- Persistent PUL
Persistent PUL:
Those in which the serum hCG levels fail to
decline and there is no evidence of
trophoblastic disease and the location of
pregnancy can not be identified.
Usually hCG are low (<500 iu/l) and have
reached to a plateau (2% of PUL)
Medical Management:
Methotrexate, 50 mg/m2 has been used
successfully in persistent PUL (90%
effective)
Surgical Management:
Laparoscopy/ laparotomy is indicated if the
woman is symptomatic or if an ectopic is
visualised.
Laparoscopy has false negative rate 3-4% (if
done too early) and false positive 5%
because of retrograde uterine bleeding.
Curettage
Not a usual practice in UK, although
common in USA
No clinical evidence to change our practice.
Conclusion
Asymptomatic PUL should be managed
conservatively as none of the methods to
predict the clinical outcome of PUL is
100% accurate.
Follow up with hCG and ultrasound until the
pregnancy is located or intervention
become necessary
Medical management should be reserved for
women with asymptomatic persisting PUL
Surgery is indicated if the woman is
symptomatic
Thank You