Ectopic pregnancy

Carleen Ong Radiographer 2nd Pelvic Ultrasound workshop 06 Dec 2014, Department of Diagnostic and Interventional Imaging

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Objective

• Important information for U/S

• Sonographic techniques

• Various type of ectopic pregnancy (EP)

• Case studies

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Important information for U/s

1.UPT / B-HCG

2.LMP & cycle length

3.Abnormal vaginal bleeding

4.Spontaneous conception / ART

5.Adnexal tenderness

6.H/O Pelvic operation

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β–hCG vs EP

• Normal pregnancy, β–hCG level doubles every

48 hours; EP may show suboptimal rise in β–

hCG

• A gestational sac should be seen on

transvaginal (TV) scan if the serum B-hCG level

is above 1800mIU/mL. (Vicken,2014)

• When intrauterine pregnancy is not identified,

ectopic pregnancy becomes the diagnosis of

exclusion.

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Techniques

• Sonographic evaluation begin with TA.

• To establish the physical relationship of the uterus and the

adnexal structures.

• Assess upper abdomen for free fluid/ large hematoma.

• TA provide a broader view of the pelvis and can help to

detect any possible intra-abdominal location of the EP.

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Techniques

• Transvaginal (TV) scan is necessary.

• Systematic scanning technique:

- Cervix

- LSCS

- Endometrium

- Ovaries

- Adnexal regions to look for mass

- Free fluid

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Techniques

- Demonstrate how is

mass related to

ovary & uterus

- Vascularities of mass

- Measure the whole

mass

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Techniques Optimise techniques:

• Focal zone

• Harmonics/ spatial compounding

• Magnification (especially when looking at small gestational

sac, to look out for yolk sac or embryo)

• Free fluid- overall gain not too low (echoes that represent

blood)

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Techniques

• When no IUGS and adnexal

mass is vaguely seen, obscured by bowel?

- Use bi-manual approach: Apply gentle pressure on the

anterior abdominal wall while the other hand

manipulates the transducer.

- Separate tubal mass/ring from ovary

- Be very careful as no IUGS does not mean abnormal

pregnancy

• Cannot find the ovary / mass?

- Return to TA

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Techniques

• Doppler is useful to identify the trophoblastic circulation,' Ring of fire’

• Be mindful that Corpus Luteum also demonstrate ‘ring of fire’

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Ectopic pregnancy (EP)

• Ultrasound findings of ectopic pregnancy are

based upon 2 important observations:

1. Identification of extrauterine gestational sac with

either yolk sac or embryo

2. Identification of indirect sign such as:

No evidence of intrauterine pregnancy in the

face of a positive pregnancy test with an adnexal

mass.

Impt: adnexal mass is Not highly predicitve.

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Early IUP

• Important to distinguish early intrauterine

pregnancy (IUP) from pseudogestational

sac that associated with EP, when YS and

Fetal pole not seen

• 2 Sonographic signs of normal IUGS:

Double decidual sign (DDS)

Intradecidual sign (IDS)

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Double decidual sign (DDS)

• 2 concentric rings surrounding an anechoic gestational sac.

Decidua

parietalis Decidua

capsularis

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Intradecidual sign (IDS)

•Echogenic area embedded in

the thickened decidua that is

eccentrically located on one

side of the uterine cavity

•A midline endometrial

cavity should be identified.

•Intradecidual sign can be seen

as early as before 5weeks.

(Chiang,2004) (Dr Yeh,1999)

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Pseudogestational sac

Intrauterine fluid collection surrounded by a single decidual layer Typically located centrally Usually oval, irregular Sometime, contain blood debris that can mimic YS/embryo

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Location of ectopic pregnancy

http://resources.ama.uk.com/glowm_www/graphics/figures/v1/0690/002f.gif

C section scar

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Tubal ectopic Pregnancy

Sonographic features:

• Empty uterus

• Thick echogenic wall surrounding a central

hypoechoic structure located between ovary and

uterus

• Separated from the ovary

• Some might be surrounded by hematoma

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Tubal ectopic

YS

Left ovary

Uterus

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When tubal ring mass is located closely

to ovary

• Is it inside ovary or outside ovary?

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Is it inside ovary or outside ovary?

• Look for normal ovarian tissue (ovarian claw

sign)

• Less than 1% of EP are intra-ovarian

–Therefore, most of the complex cysts in the ovary are

likely to be Corpus Luteum

•Always identify a normal Corpus luteum first

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If you still can’t decide

• Sliding sign: -assess whether the mass slide away from ovary or

move together inseparable with ovary.

• Compare the echogenicity of ectopic pregnancy

mass with corpus luteum: – Ectopic pregnancy more echogenic than ovarian

parenchyma (Stein,2004) – Corpus luteum usually appear less echogenic then

endometrium (Stein , 2004)

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Corpus

luteum

Ectopic P.

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Interstitial Ectopic pregnancy

• Interstitial pregnancy: Implantation of the

blastocyst within the uterine part of the fallopian

tube

• Potential of growing larger and present with

clinical symptoms later than other tubal gestation

• Can result in uterine myometrium rupture

• And cause massive hemorrhage due to

proximity of uterine vessels

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Interstitial Ectopic pregnancy

Sonographic appearance:

• Empty uterus

• Gestational sac located eccentrically

• Thin/no myometrial layer surrounding the gestation

sac. (less than 5mm) Doubilet, P. (2011, April 2).

• Presence of the echogenic line (interstitial line is

considered most reliable diagnostic value for

interstitial EP) Doubilet, P. (2011, April 2).

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Thin interstitial line

Fluid, not GS

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Interstitial Ectopic pregnancy

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Is this an Interstitial Ectopic pregnancy?

Angular

pregnancy, is an

normal

intrauterine

pregnancy that

is located

eccentrically

within the

uterine cavity.

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How to differentiate Interstitial Ectopic

pregnancy from angular pregnancy?

U/s findings Diagnosis

Little or NO visible

myometrium around

superolateral aspect

Interstitial Ectopic

GS primarily surrounded by

endometrium with adjacent

thicker myometrial layer.

Angular pregnancy

(Arleo and DeFilippis, 2014)

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Interstitial Ectopic VS Angular pregnancy

Thickness:

9mm

Clinical management is very different.

Angular pregnancy: may develop normally later:

Interstitial Ectopic Pregnancy: rupture later

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Cervical ectopic

• Account for 0.1% of all EP

• Implantation of the fertilised ovum take place

within cervix.

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Cervical Ectopic pregnancy

Typical sonographic appearance:

•Empty uterus

•Barrel shaped cervix (hour-glass shaped uterus)

•Gestational sac present below the level of the internal

cervical os

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Cervical EP vs Low lying GS

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Caesarean Section scar EP

• Implantation of the fertilised ovum within C-

section scar

• Rare

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Caesarean Section scar EP

• Sonographic features:

Empty uterus

Empty cervical canal

Development of the GS in the anterior part of the

lower uterine segment

Local thinning of myometrium or absence of

myometrium between the bladder wall and

gestational sac.

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How to differentiate Cervical/C-section

scar EP from miscarriage?

Visibility of trophoblastic circulation on Doppler examination

Spontaneous abortion: Absent of cardiac activity

EP: Live cardiac activity is usually seen

• In spontaneous abortion, sac and location should change at serial imaging.

• Closed internal os in cervical implantation

• Dilated internal os in spontaneous abortion

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Abdominal EP

• Rare

• Features:

– Empty uterus

– GS seen surrounded by bowel loops and separated

from uterus

– Free mobility of gestational sac

• TA would be superior as compared to TV scan

in abdominal EP.

• Important tip: do not assume any GS seen is

definitely in UT, always show GS in uterus by

showing myometrium surrounding it.

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Heterotopic Pregnancy

• Presence of an IUP makes the likelihood of

ectopic to be extremely unlikely.

• Risk 1:30,000 in natural conception

• However, increased with assisted reproductive

techniques(ART) . 1:100

• Interview patient:

-natural conception or ART

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IUGS inside uterine cavity

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Mass at LT AD, Yolk Sac

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Ruptured EP

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Why are some ectopic pregnancies not

seen in TV scan?

• Too small or too early in the disease progress.

• Earliest visualization of IUGS in TV is 4.5wk

• 5wks is more practical

• With yolk sac is 5.5wk

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Why are some ectopic pregnancies not

seen in TV scan?

• Presence of fibroid, ovarian pathology making

visualisation of adnexa difficult in TV.

• Especially adnexal mass that located out of

pelvis

• Non visualisation of ovaries should prompt the

need to reassess using TA scan.

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Why are some ectopic pregnancies not

seen in TV scan?

Lt Ov

Lt Ov

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Why are some ectopic pregnancies not

seen in TV scan?

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Why are some ectopic pregnancies not

seen in TV scan?

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Why are some ectopic pregnancies not

seen in TV scan?

• Complex appearance of the ectopic (can

mimic bowels )make it difficult to visualise

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Why are some ectopic pregnancies not

seen in TV scan?

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Interesting cases

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20-year-old patient

C/o sudden onset of lower abdominal pain

Lt adnexal tenderness

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Empty uterus

Fluid with echoes seen surrounding RO

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Patient is UPT negative!

Diagnosis: Ruptured left

hemorrhagic cyst

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30-year-old

11wk GA

presented with abdominal and shoulder tip pain, guarding pain

To r/o hemoperitoneum

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Result

• Patient underwent operation and removed

ruptured right rudimentary horn of uterus

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Conclusion

• Sonography plays a significant role in the

diagnosis and management of ectopic

pregnancy.

• With good techniques, ectopic pregnancy can be

diagnosed much earlier before its too late.

• Pay extra attention to the adnexal region to look

out for any mass.

• Correlate with b-HCG, LMP and follow up scan

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Acknowledgment

• Adj A/Prof Ong Chiou Li

• Yang Yin

• Chan Pei Pei Carman

• And all the sonographers

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Reference • Rumack, C., Wilson, S. and Charboneau, J. (2005). Diagnostic ultrasound. St. Louis: Elsevier

Mosby. • Ajronline.org, (2014). The Intradecidual Sign: Is It Reliable for Diagnosis of Early Intrauterine

Pregnancy? : American Journal of Roentgenology: Vol. 183, No. 3 (AJR). [online] Available at: http://www.ajronline.org/doi/full/10.2214/ajr.183.3.1830725 [Accessed 10sept. 2014].

• Arleo, E. and DeFilippis, E. (2014). Cornual, interstitial, and angular pregnancies: clarifying the terms and a review of the literature. Clinical Imaging, 38(6), pp.763-770.

• Atri, M. (2003, June 5). Ectopic pregnancy versus corpus luteum cyst revisited. Retrieved 150ct, 2014, from http://www.jultrasoundmed.org/content/22/11/1181.full

• Doubilet, P. (2011, April 2). Ectopic Pregnancy. Retrieved November 30, 2014, from http://sonoworld.com/LectureDetails/LectureDetails.aspx?Id=692&Sequence=4

• Jurkovic, D. and Mavrelos, D. (2007). Catch me if you scan: ultrasound diagnosis of ectopic pregnancy. Ultrasound in Obstetrics and Gynecology, 30(1), pp.1-7.

• M. Doubilet, P. (2012, October 11). Journal of Ultrasound in Medicine. Retrieved 28August, 2014, from http://www.jultrasoundmed.org/content/32/7/1207.long

• Sciencedirect.com, (2014). Challenges in the diagnosis and management of interstitial and cornual ectopic pregnancies. [online] Available at: http://www.sciencedirect.com/science/article/pii/S1110569013000071 [Accessed 9 Nov. 2014].

• Stein, M., Ricci, Z., Novak, L., Roberts, J. and Koenigsberg, M. (2004). Sonographic Comparison of the Tubal Ring of Ectopic Pregnancy With the Corpus Luteum. Journal of Ultrasound in Medicine, [online] 23(1), pp.57-62. Available at: http://www.jultrasoundmed.org/content/23/1/57.long [Accessed 16october. 2014].

• R Rastogi, V. (2008). Interstitial ectopic pregnancy: A rare and difficult clinicosonographic diagnosis. Journal of Human Reproductive Sciences, [online] 1(2), p.81. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2700669/ [Accessed 9 Nov. 2014].

• P Sepilian, V. (2014, September 2). Ectopic Pregnancy . Retrieved November 26, 2014, from http://emedicine.medscape.com/article/2041923-overview

• Yeh, H. (1999, February 1). Efficacy of the Intradecidual Sign and Fallacy of the Double Decidual Sac Sign in the Diagnosis of Early Intrauterine Pregnancy. Retrieved November 01, 2014, from http://pubs.rsna.org/doi/full/10.1148/radiology.210.2.r99fe23le3