This describes the ultrasound findings in various types of ectopic pregnancies. This also goes on to integrate Beta hCG into the diagnostic algorithm of ectopic pregnancy. The lecture also briefly introduces the use of progesterone levels in the diagnostic work-up of ectopic pregnancy.

1. Ultrasound
of
Ectopic Pregnancy
Durr-e-Sabih
MBBS. MSc. FRCP. FANMB
Multan- PAKISTAN

2. Any pregnancy growing
outside the normal
location in the uterine
cavity

3. General
• Mortality is decreasing
o 90% decrease in mortality but there still a ~ 9%
mortality rate 1, 2
• Incidence is increasing (better diagnosis?)
o 6 fold increase in last 25 years (almost 2% of
pregnancies can be ectopic) 2
1 Lozeau AM, Potter B. Diagnosis and management of ectopic pregnancy. Am Fam Physician
2005;72: 1707–1714.
2 Centers for Disease Control and Prevention (CDC). Ectopic pregnancy: United States, 990–
1992. MMWR Morb Mortal Wkly Rep 1995;44:46–48.

4. Risk Factors
(Disturbed tubal physiology)
• Age
• Previous ectopic
• PID
• Endometriosis
• Tubal surgery
• Adhesions
• IUCD
• In vitro fertilization
• Ovulation induction

5. Where
• Ampullary 93%
• Isthmic 4%
• Interstitital and
cornual 2.5%
• Ovarian 0.5%
• Cervical 0.1%
• Abdominal .03%

6. Consequences
• Rupture (common)
o Tubal 8.5-9.5weeks
o Cornual 12th to 20 weeks
• Abortion (into peritoneum)
o Abdominal
• Resolution

7. Classical Triad
• Pain
• Ammenorrhoea
• Vaginal bleeding

8. Why is it Difficult to Diagnose?
• Up to 50% patients do not have the “triad”
• Up to 50% no vaginal bleeding
• Up to 50% no adenxal mass
• 25% no tenderness

9. Why is it Difficult to Diagnose?
• Up to 50% patients do not have the “triad”
• Of those who had a ruptured ectopic:
o All had tachycardia
o 30% had no abdominal pain
o 49% had no rebound tenderness
o 38% had no cervical movement tenderness
o 3.1% had a negative pregnancy test
o 2.6% had negative -hCG

10. Why is it Difficult to Diagnose?
• Many will have vague symptoms or
symptoms common to early pregnancy:
o Nausea
o Breast fullness
o Fatigue
o Cramping
o Shoulder pain
o Dyspareunia

11. How then Should We Go About?
• High index of suspicion
• Screen any woman of reproductive age
with:
o Pain
o Cramping
o Bleeding

12. Ultrasound
• The most important imaging modality

13. Ultrasound
• The most important imaging modality
• Confirm ectopic
• Exclude ectopic
• Suspect ectopic

14. Ectopic is Confirmed
• When a live (or recognizable dead) embryo
is seen outside the uterus (seen in up to 30%
cases with TVS)
• Trophoblastic ring and yolk sac outside the
uterus

15. Ectopic Pregnancy

16. Ectopic Pregnancy

17. Ectopic is Excluded (or is very
unlikely)
• If an intrauterine pregnancy is seen
o Live embryo in the uterus
o Recognizable dead embryo in the uterus
o Gestational sac with a yolk sac in the uterus
o Double decidual sign

18. Ectopic is Excluded (or is very
unlikely)
• If an intrauterine pregnancy is seen
o Live embryo in the uterus
o Recognizable dead embryo in the uterus
o Gestational sac with a yolk sac in the uterus
o Double decidual sign
• Heterotopic pregnancy is seen in ART and
ovulation induction, otherwise it is very
very rare (1: 4000 – 1: 30,000 spontaneous
pregnancies)

19. Gestational Sac, Double Decidual
Sign and round contour

20. Recognizable gestational sac

21. Endometrial features of ectopic
pregnancy
• Pseudosac
• Decicual cyst, thin walled a the junction of
the endometrium/myometrium
• Persistent trilaminar endometrium during
amenorrhoea

22. Gestational Sac vs. Pseudosac
• Thick line
• Eccentric location
under the endometrial
line
• Rounded inferior
border
• Thin line
• Collection within the
endometrial canal
• Beaked inferior
border
GS Pseudo GS

23. Pseudosac

24. Adnexal features of ectopic
pregnancy
• Thick walled ring outside the uterus
• Complex non-ovarian pelvic mass
• Free peritoneal fluid
• Extra-uterine “ring of fire” on Doppler

25. Ectopic Should be Suspected
• Thick walled ring outside the uterus
• Complex non-ovarian pelvic mass
• Free peritoneal fluid
• Extra-uterine “ring of fire” on Doppler

26. Ring sign
© Gunjan Puri, Surat
© Rahul Sachdev, Delhi

27. Ring Sign
© Dr. Vikas Aoroa, Ferozpur
Pseudosac
Ring

28. Ring Sign
Confirm an extra-ovarian location

29. Ectopic Should be Suspected
• Thick walled ring outside the uterus
• Complex non-ovarian pelvic mass
• Free peritoneal fluid
• Extra-uterine “ring of fire” on Doppler

30. Complex extra ovarian
mass

31. Ectopic Should be Suspected
• Thick walled ring outside the uterus
• Complex non-ovarian pelvic mass
• Free peritoneal fluid
• Extra-uterine “ring of fire” on Doppler

32. Free peritoneal fluid

33. Ectopic Should be Suspected
• Thick walled ring outside the uterus
• Complex non-ovarian pelvic mass
• Free peritoneal fluid
• Extra-uterine “ring of fire” on Doppler

34. Ring of fire
Use Power Doppler if you can

35. Ring of fire
Use dual display to be sure you are looking at the ring

36. Ring of fire Sign

37. “Ring of Fire” Sign

38. Scanning Technique
• Start with a trans-abdominal scan to look
for masses outside the TV probe’s reach
• Follow by TVS
• Add Doppler to look for trophoblastic flow
(high diastolic, low resistance flow) and
“ring of fire sign” and flow to the embryo
• Beware of corpus luteum flow which can
have similar findings, corpus luteum is in
the ovary, ectopic mass is usually outside
the ovary

39. Mimic of ectopic

40. Corpus luteum and ectopic

41. Distended tube

42. Rare Ectopics

43. Abdominal pregnancy
• Implantation occurs within the peritoneal
cavity
• High risk of life threatening haemorrhage
and maternal mortality (7.7 times other
ectopics)
• Usually follows tubal rupture with re-
implantation on an intraperitoneal structure
• Live birth has been reported, 80%survival
after 30 weeks, 90% with serious
malformations

44. Abdominal pregnancy
• Ultrasound can miss if this pathology is not
kept in mind
• Empty uterine cavity with an abdominal
mass that includes fetus but shows no liquor
or myometrium around the fetus
• Placenta can be seen outside the uterus
• Fetal parts intermingle with maternal
abdominal viscera

45. Abdominal Pregnancy

46. Abdominal Pregnancy

48. Live abdominal
pregnancy

49. Heterotopic pregnancy
• Co-existing IUP and ectopic pregnancy
• Risk factor is assisted reproduction
particularly ovulation induction

50. Heterotopic Pregnancy

51. Heterotopic

52. Interstitial pregnancy
• Implantation in the intramyometrial portion
of the tube
• Risk factors, prior salpingectomy and IVF
• Can progress to a late stage without rupture
(~16 weeks)
• Rupture is life-threatening

53. Interstitial pregnancy
• Eccentrically located gestational sac, > 1cm from
the lateral edge of the endometrial cavity.
• Surrounding layer of myometrium is <5mm.
• “Interstitial line”, echogenic line that extends from
the upper region of the uterine horn up to the
gestational sac
• This might be the interstitial
portion of the fallopian tube
and has a 98% specificity

54. Interstitial
Ectopic
© Dr. Latha Nataranjan, Bangalore

55. Interstitial
Interstitial line

56. Interstitial vs. Cornual
• Although cornual is often used
interchangeably with interstitial pregnancy,
cornual pregnancy specifically refers to the
implantation of a blastocyst within the
cornua of a bicornuate or septate uterus, in
a unicornuate uterusor in a didelphys uterus
Challenges in the diagnosis and management of interstitial and cornual ectopic pregnancies.
Botros R; Holliday CP, AbuZaid M. Middle East Fertility Society Journal. Volume 18, Issue 4,
December 2013, Pages 235–240

57. Cervical pregnancy
• Implantation within the endocervical canal
• Risk factors; D&C, IVF, generally no
history of C-section
• Uterus can have an hourglass shape as the
cervix expands
• Cardiac activity below the internal os
• Differentiate from abortion in progress by
demonstrating sliding within the canal in
abortion and adherence in ectopic

58. Cervical Pregnancy

59. Cervical ectopic

60. Ovarian ectopic
• Ovum is fertilized and retained within the
ovary
• Gestational sac, hyperechoic ring within the
ovary along with normal fallopian tube

61. Ovarian
• Recognizable embryo
in ovarian ectopic

62. Ovarian ectopic
• Thick walled,
somewhat echogenic
cyst in the ovary
showing ring of fire
sign.
• Need to differentiate
from CL
• Very close follow-up
by hCG and
ultrasound are needed

63. Scar Pregnancy
• Implantation in a scar of a previous C-
section, separate from the endometrial
cavity
• GS visualized within the anterior wall of
the lower part of the uterus, below the level
of the bladder
• Overlying myometrium thinned
• Very close to the bladder
• Vascularity anteriorly (towards bladder)

64. Scar Pregnancy
• Before 7 weeks gestational sac is elongated
and conforms to the shape of the scar cavity
• After 7 W it extends into the uterine cavity
and can appear normally implanted
• Vascularity remains intense in the scar
region

65. C-section scar
ectopic

66. Ectopic twins

67. Ectopic twins

68. Ultrasound diagnosis of ectopic
• Can be very difficult
• Clinical presentation and ultrasound alone
might not give a clue to the actual
pathology
• We need to add β-hCG to ultrasound to
make diagnosis more accurate and sensitive

69. Combine US with -hCG
• Normally  hCG doubles every two days,
should increase by at least 66%
• If increase is <50%, it is always a nonviable
pregnancy, be it intrauterine or ectopic
• 20% ectopics can show normal  hCG
levels
• Normally  hCG plateaus at 9-11 weeks,
and starts to decline at 20 weeks, an early
plateau suggests ectopic

70. Pregnancy of Unknown Location
• Positive pregnancy test but with no
ultrasound evidence of IUP or ectopic
pregnancy or RPOC
• 5-42% in early pregnancy evaluation
• Could be:
o Early pregnancy loss
o Normal pregnancy
o Ectopic pregnancy

71. Discriminatory levels

72. Discriminatory Levels
• -hCG
• Ultrasound

73. For Abdominal Ultrasound
• Intrauterine pregnancy should be visible
by the time -hCG has achieved a value of
6000-6500mIU/ml (Third International
Standard)
-hCG

74. For Transvaginal Ultrasound
• Intrauterine pregnancy should be visible by
the time -hCG level has reached 1500-
2000mIU/ml (3rd International Standard)
-hCG

75. Beware of multiple gestations
that can have high -hCG levels
before any gestational sac is
seen!
-hCG

76. • For a gestational sac diameter > 16mm,
(TVS) an embryo should always be visible
• For a gestational sac diameter of > 25 mm,
(TAUS) an embryo should always be
visible
US

77. • For an embryonic length of >5 mm, cardiac
flicker should always be visible (TVS)
• For an embryonic length of >9 mm, cardiac
flicker should always be visible (TAUS)
US

78. Ultrasound
GS Empty uterus

79. Ultrasound
GS Empty uterus
Discriminatory levels:
-hCG > 2000MIU/ml
GS >16mm
Embryonic length > 5mm
GS
Embryo
FHR

80. Ultrasound
GS Empty uterus
<16mm >16mm
No
Embryo
Embryo No
Embryo
-hCG -hCG

81. Ultrasound
GS Empty uterus
<16mm >16mm
No
Embryo
Embryo No
Embryo
-hCG
<2000mIU
-hCG
>2000mIU
FU
US + -hCG
Ectopic/
Recent
abortion

82. Ultrasound
GS Empty uterus
<16mm >16mm
No
Embryo
Embryo No
Embryo
FH+ FH-
Blighted
ovumFU
-hCG
<2000mIU
-hCG
>2000mIU
FU
US + -hCG
Ectopic/
Recent
abortion

83. Ultrasound
GS Empty uterus
<16mm >16mm
No
Embryo
Embryo No
Embryo
FH+ FH-
CRL<5
FU
CRL>5
Dead
Embryo
Blighted
ovum
FU
FU
-hCG
<2000mIU
-hCG
>2000mIU
FU
US + -hCG
Ectopic/
Recent
abortion

84. If
• -hCG plateaus or increases very slowly
• No IUP or EP can be seen even after 5-7
days the DD is between incomplete abortion
and ectopic
• D&C to look for chorionic villi (Incomplete
abortion)

85. Complete abortion
• -hCG should fall by 15% in twelve hours

86. Sr. Progesterone
• Add serum progesterone
o Normal pregnancy has progesterone >25ng/ml,
if >60 ng/ml, high probability of an ongoing
IUP
o Low progesterone (<20ng/ml) and rising
β-hCG is almost always due to a nonviable
pregnancy

87. Prepare the patient and referring
doctor for multiple visits
• Median number of visits = 3
• Median number of days = 5
• Single visit strategy is unsafe as up to 67%
women with ectopic pregnancies might be
discharged without follow-up
A prospective evaluation of a single-visit strategy to manage pregnancies of unknown location.
Condous G, Okaro E, Khalid A, Lu C, Van Huffel S, Timmerman D et al Hum Reprod 2005 20 1398–403
doi:10.1093/humrep/deh746.

88. Risk of rupture
Low risk High risk
Age (Weeks) <8 > 8
-hCG IU/ml 1500-5000 >5000 *
Size <3cm >3cm
* Variable data
Risk factors for rupture in tubal ectopic pregnancy: definition of the clinical findings.
Goksedef, BPC , Et al .European Journal of Obstetrics & Gynecology and Reproductive
Biology .Volume 154, Issue 1, January 2011, Pages 96–99
Ectopic pregnancy grows at a rate of 1.1mm/day

89. Review
Ectopic pregnancy, Ultrasound features (not all might be present)
Tubal Empty uterus, pseudo sac, extra-ovarian mass, echogenic ring, ring-of-
fire, pelvic hematoma, complex ascites. β-hCG >1000 mIU/ml but
rising slowly or plateau
Interstitial Eccentric GS, surrounding myometrium <5mm
Ovarian β-hCG >1000 mIU/ml; Gestational sac or atypical thick walled cyst
within ovary
Scar pregnancy GS in anterior wall below the level of bladder, flow seen in anterior
wall adjacent to bladder
Cervical pregnancy Hourglass shaped uterus, GS in cervical canal, trophoblastic flow
around it, cardiac flicker might be present and seen below internal os
Abdominal
pregnancy
Empty uterus, gestational sac/fetus outside the uterus, no liquor or
visible myometrium around fetus; placenta can be seen attached to the
outside of the uterus. Fetal parts mingle with maternal abdominal
viscera
Heterotopic Intrauterine pregnancy and ectopic pregnancy seen together
Modified from: Diagnostic clues to ectopic pregnancy. Lin EP, Bhatt S, Dogra VS.
Radiographics. 2008 Oct;28(6):1661-71. doi: 10.1148/rg.286085506.

90. End