UltrasoUnd EvalUation of abnormal Early

PrEgnancy

rmg: may, 2017. @andama

Ultrasound Evaluation of Abnormal Early Pregnancy Threatened Abortion (Abnormal Vaginal Bleeding) Incomplete and Complete Spontaneous Abortion Missed Abortion Blighted Ovum (Anembryonic Pregnancy) Intrauterine Hematomas Ectopic Pregnancy Trophoblastic Disease

Early Pregnancy Evaluation

The first trimester is characterized by many important landmarks with regard to the ultimate outcome of pregnancy and is mostly defined by the first 100 days of pregnancy. Woman becomes aware of her pregnancy after missing her last period and

in that time she is already at least 4 weeks pregnant. A positive pregnancy test opens Pandora’s box, offering more questions

than answers Although, a positive pregnancy test most likely suggests an intrauterine

pregnancy, production of hCG occurs also by tumors (dysgerminoma, choriocarcinoma) or maldevelopment of pregnancy (ectopic pregnancy or mola hydatidosa)

Ultrasound evaluation of an early pregnancy includes detection of the pregnancy location (extrauterine or intrauterine), type of pregnancy (one—fetus pregnancy, multiple pregnancy, molar

pregnancy) viability of the pregnancy and establishment of the gestational age.

Basic ultrasound markers for normal pregnancy are intrauterine gestational sac, morphologically normal embryo and its heart action

Early Pregnancy Failure and Vaginal Bleeding

Early pregnancy failure is defined as a pregnancy that ends spontaneously before the embryo is detected by ultrasound at the gestational age in which visualization of viable embryo should occur Clinical presentation of the symptoms such as vaginal bleeding and

abdominal pain, with or without the expulsion of products of conception is suspected of a spontaneous abortion. For ultrasound evaluation, it is important to distinguish threatened,

complete and incomplete abortion

Threatened Abortion (Abnormal Vaginal Bleeding)

• Threatened abortion is the clinical term used to describe symptom such as vaginal bleeding during the first 20 weeks of pregnancy in women who, on the basis of clinical evaluation, are considered to have a potentially living embryo/fetus

• Sonographic evidence of vaginal bleeding can be identified as a perigestational hemorrhage in 5–22% of women with symptoms of threatened abortion

• Most of the small hemorrhages resolve without clinical sequelae, while in some cases spontaneous abortion may occur.

Incomplete and Complete Spontaneous Abortion

Incomplete abortion is the passage of some, but not all fetal or placental tissue through the cervical canal. In complete abortion, all products of conception are expelled

through the cervix In incomplete abortion, the uterine debris may consist of a

combination of products of conception, blood and decidua An echogenic and vascularized mass within the uterine cavity

supports the diagnosis of retained products of conception

Incomplete and Complete Spontaneous Abortion

Transvaginal power Doppler Image of an irregular uterine cavity. Note

abundant vascularity demonstrating residual placental tissue

A longitudinal section of the uterus showing the uterine cavity, which contains a large amount of irregular echogenic tissue. This is a typical ultrasound finding in incomplete miscarriage.

A thin endometrial echo in a woman with a positive pregnancy test and a history of heavy bleeding is highly suggestive of complete miscarriage.

Missed Abortion

The diagnosis of missed abortion is determined by the ultrasound identification of an embryo/fetus without any heart activity. It is relatively easy to make this diagnosis by means of the

transvaginal color Doppler ultrasound. The main parameter is the absence of the heart beats and the lack of

color flow signals at its expected position after the 6th gestational week.

Transvaginal color Doppler scan of a missed abortion. Prominent blood flow signals are obtained from the spiral arteries, while

absence of heart activity is noted by color Doppler

A case of missed miscarriage at 8 weeks’ gestation. An irregularly shaped gestation sac is seen containing a small amniotic cavity (A) with no fetal pole.

Blighted Ovum (Anembryonic Pregnancy)

Blighted ovum (anembryonic pregnancy) refers to a gestational sac in which the embryo either failed to develop or died at a stage too early to visualize. The diagnosis of anembryonic pregnancy is based on the absence of

embryonic echoes within the gestational sac, large enough for such structures to be visualized, independent of the clinical data or menstrual cycle. If the sac is not increasing in size by at least 75% over a period of 2 weeks,

the definition of this pathological condition in early pregnancy is a blighted ovum. To confirm the diagnosis, these findings should be correlated with other

clinical and sonographic data including the presence of a yolk sac.

The diagnosis of a blighted ovum is in 100% of cases by 2D real-time ultrasonography examinations when performed 2 weeks apart after absence of embryo development has been confirmed

Transvaginal sonogram of an anembryonic pregnancy. Note the absence of the living embryo and the yolk sac indicative of an

anembryonic pregnancy. Color Doppler image presents signals obtained from the spiral arteries and other

maternal vessels

Intrauterine Hematoma

Intrauterine hematomas are defined as sonolucent crescent or wedge shaped structures between chorionic tissue and uterine wall, or fetal membranes. By localization we can divide them into retroplacental, subchorionic,

marginal and supracervical. The most severe are large, central, retroplacental hematomas in

which separation of chorionic tissue from basal deciduas occurs by mechanism similar to a mechanism of abruption of the placenta.

The most common causes of intrauterine hematoma are: Disturbed trophoblast invasion and defect in spiral arteries transformation Infection Mechanical factors Autoimmune factors Hematological factors.

It is important to stress that finding of an intrauterine hematoma does not

immediately indicate the likelihood of a spontaneous abortion. As the measure of precaution rather classify this pregnancy into a high-risk

group with additional necessity for further intensive monitoring

Prognostically, there are two main elements, which determine then pregnancy outcome. (Location and size) The location of the hematoma is more predictive sign than the volume of

hematoma. If the bleeding occurs at the level of the definitive placenta (under the cord

insertion), it may result in placental separation and subsequent abortion. Conversely, a subchorionic hematoma detaching only a membrane

opposite to the cord insertion could probably reach a significant volume before it affects normal pregnancy development. Supracervical hematoma has much better prognosis because it is easily

drained into the vagina and for this reason it doesn’t represent mechanical factor for compression of the uteroplacental vessels. Higher incidence of spontaneous abortions has been reported in the cases

where hematoma has been localized in the fundal or corporal region, which could be attributed to placental location in that area.

Transvaginal sonogram of a large-volume hematoma located in

fundal-corporeal region. Note the uterine blood flow signals on the side of the hematoma

Ectopic Pregnancy

oEctopic pregnancy represents implantation of the fertilized ovum outside the uterine cavity.

o In 95% of the cases it is localized in the fallopian tube (95%), but sites like abdominal cavity, ovary, intraligamentous location, cornual, intramural or cervical sites are not unusual

oMechanical factors predisposing pathomorphological site of implantation are: low-grade pelvic infection (main cause for the faulty implantation), peritubal adhesions (result of the previous PID), and salpingitis with the partial or total destruction of the tubal mucosa.

oectopic pregnancies do occur in totally normal tubes, suggesting that abnormalities of the conceptus or maternal hormonal changes may act as etiological factors.

Risk factors for ectopic

STD-PID Assisted reproductive techniques Abnormalities of the conceptus Uterine malformations Maternal hormonal changes Surgical procedures in pelvis IUD Previous ectopic pregnancy Fibroids Cigarette smoking

Ectopic oSymptoms can vary from vaginal spotting to vasomotor shock with

hematoperitoneum. oThe classic triad;- delayed menses, irregular vaginal bleeding and

abdominal pain oDdx; normal intrauterine pregnancy, salpingitis, torsion or rupture of the ovarian cyst, bleeding corpus luteum, endometriosis, appendicitis, gastroenteritis, diverticulitis, conditions affecting urinary tract

Role of Transabdominal US in diagnosing ectopic

The absence of gestational sac inside the intrauterine cavity at 6 weeks’ gestation raises the suspicion of an ectopic pregnancy Signs for ectopic pregnancy could be divided into uterine and

extrauterine, some of them being diagnostic or just suggestive Diagnostic signs include: absence of the intrauterine gestational sac

surrounded with double ring, absence of the yolk sac and/or fetal structures inside the gestational sac and presence of extraovarian adnexal structure Suggestive signs are: uterine enlargement with thickened

endometrium and blood orcoagulum in the retrouterine space

Intrauterine gestational sac surrounded with double ring with clear embryonic echo is considered to be strong evidence against ectopic pregnancy because heterotopic, pregnancy (intrauterine and ectopic), coincide rarely, but shouldn’t be so easily ignored, especially in the patients undergoing some of the methods of assisted reproduction Pseudogestational sac can be demonstrated in 10–20% of patients

with ectopic pregnancy3 as a mixed echo pattern of endometrium that results from a decidual reaction, fluid, or both. Gestational sac located inside adnexa with clear embryonic echo and

heart activity directly proves ectopic pregnancy. The most common finding is an unspecific adnexal tumor. Free fluid in the retrouterine space is seen in 40–83% of cases

A case of heterotopic pregnancy. The lowersac (1) is implanted into the cervix, whereas the upper sac (2) is normally located within the uterine cavity.

Heterotopic pregnancy sonogram showing intrauterine pregnancy and concurrent adnexial pregnancy

Trophoblastic Disease

• Trophoblastic diseases are roughly divided into hydatidiform mole and choriocarcinoma, both are classified into subgroups in the pathological classification.

• There are also clinical classification and FIGO staging in the diseases.

Clinical classification of GTD

FIGO staging for GTD

Total Hydatidiform Mole

• It is abnormal pregnancy, where all placental villi change to molar vesicles and fill uterine cavity, while there is no embryo, fetus, nor umbilical cord

• Amnion is, however, found in some cases • Trophoblasts are scattered in the decidua and myometrium, and

called syncytial endometritis • Molar cysts may spread into blood vessel, which is the intravascular

mole, and rarely metastasis appears in distant organ. • Chromosomes are usuall diploid 46, XX

Hydatidiform mole

• Patients usually have severe nausea and vomiting (hyperemesis) • Hypertension and proteinuria (pre-eclampsia) • No fetal movement • No fetal heart beat by ausucultation or Doppler dector • Greater uterine size than normal pregnancy, abdominal pain, hemorrhage,

and expelling molar vesicles in some cases, and • Higher urinary or serum hCG level usually than 100,000 mIU/mL USS findings • Enlarged uterus • Hyperechoic central uterine mass with numerous discrete anechoic cystic

spaces (Snowstorm / granular appearance) • The molar tissue demonstrates the bunch of grapes sign which represents

hydropic swelling of trophoblastic villi

bunch of grapes sign – molar pregnancy

Partial molar pregnancy

• One triplet changes into total hydatidiform mole. F1, F2—two triplet fetuses, M—mole.

M F2

F1

Partial Hydatidiform Mole

• It is partial change of placental villi into the mole, which is associated with embryo, fetus or fetal parts

• Fetal anomalies are common. • Chromosomes are usually triploids, 69, XXX, 69, XXY, or 69, XYY.

Invasive Hydatidiform Mole

• It is the invasion of molar cysts into myometrium with destruction and hemorrhage.

• Intravascular mole and placental polyp are excluded from the invasive mole.

• The lesion is formed either in total or partial mole, usually after the molar evacuation, although the invasion may develop before the termination.

• The change is visually noted in surgical specimen and microscopically confirmed, where the trophoblasts proliferate, hemorrhage and necrosis are found in the myometrium

Choriocarcinoma

• It is solid trophoblastic tumor developed primarily in myometrium, or in distant organs and tissues, usually after the removal of or partial hydatidiform mole, and also infrequently after the abortion or deliveries.

• They are gestational choriocarcinoma or gestational trophoblastic disease (GTD)

Gestational choriocarcinoma development is related to pregnancy, and three categories are classified.

• a. Uterine choriocarcinoma is the most common, developed in the uterus afterhydatidiform mole, and rarely after abortion or normal delivery.

• b. Extrauterine choriocarcinoma develops primarily at the place of ectopic pregnancy, while there is no tumor in the uterus.

• c. Intraplacental choriocarcinoma is found in the placenta mainly after delivery. Intraplacental choriocarcinomas were reported to be associated with viable pregnancy

A longitudinal section of the uterus showing a 6 week gestation sac (GS) normally implanted within the uterine cavity. A Nova T IUCD (arrow) is also seen displaced into the upper part of the cervical canal If an intrauterine pregnancy occurs with an IUCD in situ, removal of the IUCD is the preferred option. Leaving the device in situ is associated with a high rate of miscarriage and an increased risk of hemorrhage, sepsis, preterm delivery and of stillbirth.

The Others

Placenta and amniotic fluid

Placenta previa

If the placenta overlies the internal os, then vaginal delivery can occur only through the placenta. With the major degrees of placenta previa, life-threatening bleeding will occur when the uterus contracts and the placenta separates.

Amniotic fluid volume

• Subjective assessment • Single deepest pool (2-8cm AP) • Amniotic flud index (5-25cm)

• Image above: Oligohydramnios at 35 weeks’ gestation. The largest vertical pool measures 1.8 cm and the AFI is 3.0 cm. Causes of oligohydromnios: uteroplacental insufficiency, amniotic

mabrance rapture, abnormal fetal renal function

Anhydramnios at 28 weeks’ gestation in a fetus with polycystic kidney disease. Note the grossly enlarged and echo-bright stroma of the cystic kidney.

Image 1: Polyhydramnios in a 24-week pregnancy in which the fetus is severely anemic due to Rhesus incompatability. The largest vertical pool measures 10.16 cm. Image 2: Polyhydramnios in a 32-week pregnancy in which duodenal atresia is suspected. The largest vertical pool measures 12.5 cm

Some fetal abnormalities - sonographically

• Anencephaly • Spina bifida • Hydrocephalus • Encephalocele • Microcephaly • Agenesis of the corpus callosum • Hydranencephaly • Porencephalic cyst • Cystic adenomatoid malformation

• Bowel atresia / obstruction • Omphalocele • Gastroschisis • Renal agenesis • Congenital cystic disease of the

kidneys • Obstructive uropathy • Fetal hydrops • Absent limbs (Amelia, meromelia,

phocomelia)

Anencephaly As ossification of the fetal skull is normally completed by 11 weeks, the diagnosis of absence of the cranium or anencephaly can be made reliably after this gestation. Images below A. At 12 weeks, absence of the skull bones (acrania) B. At 23 weeks the fetal brain tissue can no longer be visualized. Note the typical frog’s eyes appearance

Hydrocephalus Hydrocephalus describes the pathological increase in the size of the cerebral ventricles and head circumference These features are commonly associated with spina bifida towards the end of gestation. Ventriculomegaly describes the appearance of the lateral ventricles when their diameter is above the normal range for gestation. Often the first clues to the presence of spina bifida are a lemon-shaped skull and ventriculomegaly Transverse section of the head demonstrating ventriculomegaly in a 20-week fetus with spina bifida. Note the typical lemon shape of the skull

Transverse section of the fetal abdomen demonstrating an anterior abdominal wall defect of an omphalocele at 19 weeks. Note that the umbilical vein inserts into the apex of the defect

Transverse section of a fetal abdomen at 20 weeks demonstrating the free-floating loops of bowel of a gastroschisis. Note the normal insertion of the umbilical cord.

Transverse section of the fetal body demonstrating fetal hydrops. Gross ascites (large arrow) is present, outlining the fetal liver. Mild skin edema (arrow) is also present.

Thanatophoric dysplasia. The radius is extremely short and bowed, producing the characteristic ‘telephone receiver’ shape.