utrasound in Early pregnancy

1. USG IN EARLY PREGNANCY AND
DIAGNOSIS OF ECTOPIC PREGNANCY
AND ITD DD’S.
DR.M.VINOTHKUMAR
APOLLO SPECIALITY HOSPITAL

2. GESTATIONAL SAC
 The frst reliable gray-scale evidence of an IUP is visualization of the
gestational sac within the thickened decidua - intradecidual sign.
Intradecidual sac sign. A, Sagittal scan at 4 weeks, 4 days shows
implantation site as a 2-mm focal thickening of posterior endometrium (arrow).
The chorionic fluid in the sac is just barely visible. The mass slightly displaces
the endometrial stripe and has a slightly echogenic rim. B, Color Doppler
image shows prominent terminal portion of a spiral artery (arrow) extending up
to the sac.

3. DOUBLE-DECIDUAL SIGN
 Method of differentiation between an early IUP and the
pseudosac of an ectopic pregnancy.
 usually be identifed by about 5.5 to 6 weeks.
 The double-decidual sign is based on visualization of
the gestational sac as an echogenic ring formed by the
decidua capsularis and chorion laeve eccentrically
located within the decidua vera forming two echogenic
rings
Decidual layers. Sagittal transvaginal
sonogram at 7 weeks shows the
gestational sac (arrowhead) and the
maternal decidua (arrow) as separate
echogenic bands.

4.  A well-defned double-decidual sign is an accurate
predictor of the presence of an intrauterine
gestational sac - accurate predictor of an
intrauterine gestational sac.
 Absent double-decidual sign : fluid-filled pseudosac
associated with an ectopic pregnancy -
nondiagnostic.

5. YOLK SAC
 first structure to be seen normally within the
gestational sac.
 critical in differentiating an early intrauterine
gestational sac from a pseudosac.
 Although the double-decidual sign is not 100% specifc
for presence of an IUP, the identifcation of a yolk sac
within the early gestational sac is diagnostic of IUP

6. YOLK SAC
 The yolk sac remains connected to the
midgut by the vitelline duct. In some cases the
vitelline duct can be demonstrated sonographically
embryo at 8 weeks with the vitelline duct (VD) connecting to
the yolk sac (YS). There is also a subchorionic
hemorrhage

7. YOLK SAC
 number of yolk sacs present can be helpful in
determining amnionicity of a multifetal pregnancy.
 monochorionic monoamniotic (MCMA)
twin gestation, there will be two embryos, one
chorionic sac, one amniotic sac, and one yolk sac.
Two separate yolk sacs are seen
within a single gestational sac at
6 weeks on 2-D (A) and 3-D (B)
images.

8. EMBRYONIC CARDIAC ACTIVITY
 Using TVS, an embryo with a CRL as small as 1 to 2 mm may be identifed immediately
adjacent to the yolk sac.
 In normal pregnancies the embryo can be identifed in gestational sacs as small as 10
mm and should always be identifed when the MSD is 16 to18 mm or larger with optimal
scanning parameters and high-resolution TVS.
 Normal embryonic cardiac activity is greater than 100 beats per minute
Normal 6-week embryo. A, Image shows 6-week embryo (calipers) adjacent to the
yolk sac. B, M-mode ultrasound shows a heart rate of 141 beats/min.

9. UMBILICAL CORD AND CORD CYST
 Formed at the end of the sixth week (CRL = 4.0 mm).
 Two umbilical arteries, a single umbilical vein, the allantois, and
yolk stalk (also called the
omphalomesenteric duct or vitelline duct), all of which are
imbedded in Wharton’s jelly.
 Arise from the fetal internal iliac arteries and in the newborn
become the superior vesical arteries and the medial umbilical
ligaments.
 Vein in the newborn becomes the ligamentum
teres, which attaches to the left branch of the portal vein.
 allantois is associated with bladder development
and becomes the urachus and the median umbilical ligament. It
extends into the proximal portion of the umbilical cord.

10.  Cysts and pseudocysts within the cord have been
described in the frst trimester.
 Cysts are usually seen in the eighth week and disappear by the 12th
week.
 Cysts may originate from remnants of the allantois or
omphalomesenteric duct and
characteristically have an epithelial lining and usually resolve in
utero.
 It is hypothesized that the cyst is an amnion inclusion cyst that
occurs as the amnion was enveloping the umbilical cord.
UMBILICAL CORD AND CORD CYST

11. UMBILICAL CORD CYST.
 Umbilical
Umbilical cord cyst. A, Live embryo at
9 weeks’ menstrual age with a cyst on the
cord (arrow) close to the embryonic end.
B, Color Doppler image of the cord and
cyst with flow in the vessels of the cord and
no flow in the cyst.
C, Another example of a 9-week cord cyst
(arrow) in the midportion of the cord, with
good visualization of the whole cord,
embryo, and yolk sac.

12. ESTIMATION OF GESTATIONAL AGE
Gestational Sac Size
 possible to estimate gestational age from weeks 5 to
10 on the basis of gestational sac size.
 MSD is measured using the sum of three orthogonal dimensions of the
fluid–sac wall interface divided by three.
 Normally, a yolk sac will be present when the MSD is 8 mm or less, and an
embryo will be seen at 16 mm or less.
 Gestational sacs larger than 8 mm without a yolk sac or larger than 16 mm
without an embryo should be watched carefully for impending early
pregnancy failure.
 Occasionally, a gestational sac up to 20 mm will be seen without an embryo,
and the outcome will be a normal pregnancy

13. CROWN-RUMP LENGTH
 Using TVS, the embryo can be visualized from the fifth week onward.
 Conventional CRL charts are available beginning from 6 weeks, 2
days.

14. EARLY PREGNANCY FAILURE
 The pregnancy shows sonographic evidence that the process of
growth and development has stopped.
 A large, empty gestational sac; a gestational sac and yolk sac only; a
smaller-than-normal or even an appropriate sized embryo with no
cardiac activity; or only the remnants of a gestational sac all could be
appropriately described as “early pregnancy failure.”
 Early pregnancy failure indicates that whatever is in the endometrial
cavity, it will never produce a live baby

15. SONOGRAPHIC DIAGNOSIS OF EMBRYONIC DEMISE
Embryonic Cardiac Activity
 most important feature for the confrmation of
embryonic and fetal life is the identifcation of cardiac activity.
 The presence of cardiac activity indicates that
the embryo is alive.
 The absence of cardiac activity does not necessarily indicate
embryonic demise, however,
because TVS can identify a normal early embryo without
cardiac activity

16. SONOGRAPHIC DIAGNOSIS OF EMBRYONIC DEMISE
Gestational Sac Features
 In many patients the embryo is not visualized on the initial
sonogram, and the diagnosis of pregnancy failure cannot be
made on the basis of abnormal cardiac activity.
 In these patients the diagnosis of pregnancy failure may be
made based on gestational sac characteristics.
 In TVS : MSD of 8 mm or more without a demonstrable yolk
sac, or 16 mm with no demonstrable embryo, is abnormal and
indicates pregnancy failure.

17. SONOGRAPHIC DIAGNOSIS OF EMBRYONIC DEMISE
Gestational Sac Features
 Additional support for the diagnosis of early
pregnancy failure
 distorted gestational sac shape, thin trophoblastic reaction (<2
mm), weakly echogenic trophoblast, and abnormally low position
of the gestational sac within the endometrial cavity.
Early pregnancy failure with irregular sac

18. AMNION AND YOLK SAC CRITERIA
 Visualization of the amnion in the absence of a sonographically
demonstrable embryo after 7 weeks’ MA is abnormal and diagnostic
of a nonviable pregnancy.
 The amnion is usually visualized after the embryo, so it should not
be visualized in the absence of an embryo.
 fndings that may be useful in the diagnosis of embryonic demise
include a collapsing, irregularly marginated amnion and yolk sac
calcifcation.
Collapsed amnion.
The embryo is small with a crown-rump length
(calipers) of 7 mm, consistent with 7 weeks. No cardiac
activity is seen. The amniotic membrane (arrow) is
collapsed adjacent to the embryo.
Sonographic Diagnosis of Embryonic Demise

19. SONOGRAPHIC DIAGNOSIS OF EMBRYONIC DEMISE
EMBRYONIC BRADYCARDIA
 A heart rate less than 80 beats/min in embryos with a CRL less than
5 mm was universally associated with subsequent embryonic
demise.
 Heart rates above 100 beats/min are considered normal in embryos
of CRL less than 5 mm.
 In embryos of CRL 5 to 9 mm, a heart rate less than 100 beats/min
was always associated with abnormal outcome, with the normal rate
120 beats/min or more. In embryos of CRL 10 to 15 mm, a heart rate
less than 110 beats/min appears to be associated with a very poor
prognosis.

20. SONOGRAPHIC DIAGNOSIS OF EMBRYONIC DEMISE
YOLK SAC SIZE AND SHAPE
 An abnormally large yolk sac is often the frst sonographic indicator
of pathology and is invariably associated with subsequent embryonic
demise.
 Yolk sac abnormalities should be used as a predictor of abnormal
outcome and patients with abnormal yolk sac size or shape should
be followed closely.
 If the fetus survives the first trimester, follow-up examination should
be performed at 18 to 20 weeks’ MA to evaluate the fetus for
anomalies. Genetic counseling should also be offered.
 A calcifed yolk sac appears as a shadowing echogenic mass in the
absence of any other identifable yolk sac.

21. Intrauterine embryonic death with yolk
sac calcification

22. Twins: one normal, one with small
sac.
Small gestational sac and embryo

23. SONOGRAPHIC DIAGNOSIS OF EMBRYONIC DEMISE
SUBCHORIONIC HEMORRHAGE
 Elevation of the chorionic membrane.
 May be associated with vaginal bleeding.
 The chorionic membrane is stripped from the endometrium (decidua
vera) and elevated by the hematoma.
 Acute hemorrhage is usually hyperechoic or isoechoic relative to
the
placenta.

24. Small subchorionic bleed.
Moderate subchorionic bleed

25. RETAINED PRODUCTS OF CONCEPTION
 Echogenic mass of tissue flling
the endometrial canal.
 Focal increased vascularity is of great importance in distinguishing
between blood clots and RPOC.
 There can be a single vessel or a large group of vessels, either
superfcially in the myometrium or extending deep within it.

26. ECTOPIC PREGNANCY
Clinical Presentation
 Classic clinical triad of pain, abnormal vaginal bleeding, and
a palpable adnexal mass is only present in approximately
45% of patients with ectopic pregnancy.

27. ECTOPIC PREGNANCY
SONOGRAPHIC DIAGNOSIS
 When women present with a positive pregnancy test or a history
suggestive of ectopic pregnancy (missed period,pain, unprotected
intercourse), it is critical to identify the presence and location of the
gestational sac. Pelvic ultrasound and especially TVS must be the
frst line of imaging investigation.
 Always look for free fluid in the hepatorenal space
sense of the degree of blood loss. Although hemodynamically stable
with a large volume of fluid loss, the patient could decompensate
rapidly.
 Fluid seen in the hepatorenal space should impart a
greater sense of urgency to the surgeon.
 The sonographic demonstration of a live embryo in
the adnexa is specifc for the diagnosis of ectopic pregnancy.

28. SPECIFC FINDINGS
 The intradecidual sign and the double-decidual sign can
be used to identify an IUP before visualization of the
yolk sac or embryo.
 The double-decidual sign must be distinguished from
the decidual cast or pseudogestational sac of ectopic
pregnancy.
 A pseudosac is an intrauterine fluid collection
surrounded by a single decidual layer as opposed to the
two concentric rings of the doubledecidual sign.

29. Pseudogestational sac. A, Coronal transvaginal scan of a 8
weeks with pelvic pain. There is a rounded intrauterine sac flled
with low-level echoes. No yolk sac or embryo is seen. There is a
single echogenic ring around the fluid (arrow). This is a fluid-flled
endometrial canal, a decidual cast, or pseudogestational sac. B,
Sagittal transvaginal scan shows a large pseudogestational sac
with echogenic debris. Note the acute angle at the lower end,
uncommon in a gestational sac

30. Ruptured ectopic pregnancy with hemoperitoneum. A 35-year-old woman presented at 6 weeks’ gestation with
right lower quadrant pain. A, Sagittal transvaginal scan shows echogenic material within the endometrial cavity but
no gestational sac. Blood clot is (*) seen around the uterus. B, Coronal transvaginal scan of the uterus (U) and a
complex right adnexal mass with a sac at its posterior aspect (arrow). C, Coronal color Doppler sonogram with no
vascularity seen. D, Sagittal scan of the left upper abdomenshowing free fluid (*)

31. NONSPECIFC FINDINGS
 When the sonographic fndings are nonspecifc, correlation with serum β-hCG
levels improves the ability of sonography to distinguish between intrauterine
and ectopic pregnancy.
 A negative β-hCG essentially excludes the presence of a live pregnancy.
 The serum β-hCG test yields positive results at approximately 23 days of
gestational age
 If the hCG level(500 to 1000 mIU/mL) is above the threshold level, an ectopic
pregnancy becomes the diagnosis of exclusion.
 The β-hCG level in a normal pregnancy has a doubling time of approximately
2 days, whereas patients with a dead or dying gestation have a falling β-hCG
level.
 Patients with ectopic pregnancy usually have a slower increase in hCG levels.

32. Ectopic tubal ring
 concentric ring created by the trophoblast of the ectopic pregnancy
surrounding the chorionic sac - more echogenic than ovarian
parenchyma, but may be of mixed echogenicity
 Found in 49% of patients with ectopic pregnancy and in 68% of
unruptured tubal pregnancies, using TVS.
 The tubal ring can usually be differentiated from a corpus luteum cyst
because the cyst is eccentrically located with a rim of ovarian tissue.
 echogenic - free pelvic fluid (hemoperitoneum) strong suspicious for
ectopic pregnancy.
 presence of small amounts of nonechogenic free fluid is nonspecifc and
is seen in normal patients.

33. Ectopic pregnancy seen as echogenic mass. A 33-year-old woman presented at 7 weeks’ gestation
with right lower quadrant pain. A, Transvaginal scan shows an empty uterus. B, Free fluid (ff) in the cul-
de-sac. C, In right adnexa there was a 1.4 × 1.6–cm echogenic mass (arrow) adjacent to a normal ovary
(ro). The mass was focally tender to palpation with the vaginal probe.
D, Power Doppler ultrasound shows minimal internal vascularity

34. Isthmic ectopic pregnancy. A 35-year-old woman (G3P1A1) presented with no pain but was at risk for an
ectopic pregnancy. A, Coronal transvaginal scan shows an empty uterus and a tubal ring (arrow) immediately adjacent to the
uterus. B, Magnifed view of the ring shows a gestational sac with a yolk sac, confrming an ectopic pregnancy. C, Color flow
Doppler ultrasound shows increased vascularity around the sac with high-velocity flow. D, At laparoscopy, ectopic site can be
seen bulging the isthmic portion of the tube (arrow). It was successfully removed by salpingostomy.

35. Implantation Site
 95% of ectopic pregnancies occur in the ampullary or isthmic portions of the
fallopian tube.
 Second most common site - interstitial pregnancy.
Interstitial line sign
 A thin, echogenic line extending from the endometrial canal up to the center of
the interstitial sac or hemorrhagic mass.
 The interstitial ectopic pregnancy is usually surrounded by trophoblast but
should not have a double-decidual sign.
Cervical scar implantation
 Painless vaginal bleeding and a history of one or more cesarean sections.
 Sac implanted in the lower uterine segment, with local thinning of the
myometrium.

36. Cesarean scar implantation. A 33-yearold woman (G5P2SA2; two prior
cesarean sections) presented at 10 weeks’ gestation. A, Transabdominal scan
shows a sac (arrow) in the lower uterine segment. B, Transvaginal scan shows a
sac in the lower segment with an embryo

37. Ovarian Masses
corpus luteum cyst
 usually less than 5 cm in diameter.
 Internal septation and echogenic debris may be present
secondary to internal hemorrhage
Hemorrhagic corpus luteum cyst (arrow) at 6 weeks.
A, The flamentous bands within the cyst are consistent
with hemorrhage. There is also a paraovarian cyst (p),
which is echolucent.
B, Hemorrhaging corpus luteum with a small amount
of adjacent free fluid. C, The vascularity is a typical ring
of fre with flow in the wall around the cyst.
D, Pathologic specimen of an ovary
with a corpus luteum cyst

38.  Torsion, rupture, and dystocia have all been
described as complications of ovarian cystic masses associated with
pregnancy.
Uterine Masses
 Uterine fibroids are a common pelvic mass often identifed during
pregnancy and often associated with localized pain and tenderness. Most
fbroids do not change in size during pregnancy, although some may
enlarge rapidly as a result of estrogenic stimulation.
 Infarction and necrosis may occur because of rapid growth.

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