Chapter 32 - Fetal Environment and Maternal Complications

What are some maternal links to developing placental abruption ?

-hypertension -preeclampsia -Cocaine use -Cigarette smoking -poor nutrition -Trauma

What are the three main parts of the placenta?

1. Chorionic plate (Closest to the fetus) 2. The placental substance 3. Basal plate (Adjacent to the uterus)

What are some sonographic findings for TORCH?

1. Intracranial calcifications 2. Microcephaly 3. Micropthalmia 4. Ventriculomegaly 5. Hepatosplenomegaly

What are the sonographic findings of Uterine Synechia?

1. Linear, echogenic band of tissue traversing the uterine cavity 2. The band does not involve fetal parts and the normal fetus appears to move freely.

What are the clinical findings for Placenta previa?

1. Painless vaginal bleeding 2. Previous C section or uterine surgery 3. Possibly asymptomatic

What are the sonographic findings of Placenta Accreta, Increta, and Percreta?

1. Placenta previa 2. Loss of normal hypoechoic interface between the placenta and the myometrium

What are the clinical findings of Placenta Accreta, Increta, Percreta?

1. Previous C section or uterine surgery 2. Painless vaginal bleeding if placenta previa is present 3. Possibly asymptomatic

What are the sonographic findings of Vasa Previa?

1. identification of vessels over the internal os of the cervix with the use of color doppler 2. Velamentous cord insertion

A definitive placenta may not be identified songraphically until after ... to ... weeks

10 - 12 weeks

The placenta consists of how many Cotyledons ?

10 - 30

Fetuses with a 2VC have a ____ % chance of having other abnormalities

20%

What is the most common abnormality of the umbilical cord?

2VC two vessel cord Single umbilical artery

What should the thickness of the placenta not exceed?

4 cm

What is the typical weight of the placenta and what is the diameter?

450 - 550 grams 16 - 20 cm

What is the amniotic fluid index and how is measured?

AFI Used to evaluate the volume of amniotic fluid. Measured using the anteroposterior dimensions with the transducer perpendicular to the floor, obtained from the four quadrants of the amniotic sac and adding them together.

What is Placenta Accreta?

Abnormal "A"dherence of the placenta to the myometrium in an area where the decidua is either absent or minimal.

What is velamentous cord insertion?

Abnormal insertion of the umbilical cord into the membranes beyond the placental edge

What is a 2VC associated with?

Abnormalities of all of the major organ systems IUGR

What is a Circumvallate Placenta?

Abnormally shaped placenta caused by the membranes inserting inward from the edge of the placenta, causes a curled up placenta contour

What is another term used for Placental abruption?

Abruptio placentae

Where is the most common location for a Chorioangioma to form?

Adjacent to the umbilical cord insertion site at the placenta.

What are uterine Synechia associated with?

Although typically isolated findings, they can be associated with Premature rupture of membranes, premature delivery, and placental abruption.

What is a Succenturiate Placenta?

An additional accessory smaller lobe located separate from the main segment of the placenta.

What is Umbilical vein varix associated with?

Aneuploidy growth restriction hydrops demise

What is the S/D ratio?

Asses the vascular resistance in the placenta by taking a sample of the umbilical artery.

What is another term for Marginal cord insertion?

Battledore placenta

What is a Hemangioma and where are they typically located?

Benign tumor composed of blood vessels Typically seen near the cord insertion site into the placenta

What is Chorioangioma?

Benign tumor of the placenta

What does the umbilical vein do?

Carries oxygenated blood from placenta to fetus. (enters the fetal abdomen and proceeds cephalad to connect to the left portal vein)

What is the most common placental Tumor?

Chorioangioma

What part of the placenta is the fetal contribution?

Chorion frondosum : Portion derived from the blastocyst

What does the Chorion Frondosum contain?

Chorionic villi

How is Placental abruption further described?

Complete abruption Partial abruption Marginal abruption

What is Marginal cord insertion?

Cord insertion is at the edge of the placenta.

What is an Allantoic Cyst?

Cyst found within the umbilical cord, adjacent to the umbilical vessels.

What part of the placenta is the maternal contribution?

Decidua basalis : the endometrium beneath the developing placenta

What does the umbilical cord develop from?

Develops from the fusion of the yolk stalk and the vitelline duct early in gestation.

What are the possible causes of a thickened placenta?

Diabetes Mellitus Maternal Anemia Infection Fetal Hydrops Rh isoimmunization Multiple gestation

What are the possible causes of a thin placenta?

Diabetes Mellitus (long-standing) Intrauterine growth restriction Placental Insufficiency Polyhydramnios Preeclampsia Small for dates fetus

What do the Umbilical arteries do?

Enter the fetal abdomen and carry deoxygenated blood from the fetus to the placenta. Once they enter the abdomen they proceed caudal around the bladder to connect to the fetal internal iliac arteries.

What is Meconium?

Fetal stool that is composed of fetal skin, hair, amniotic fluid, bile.

What is the chorionic villi?

Fingerlike projections of gestational tissue that attach to the decidualized endometrium and allow transfer of nutrients from the mother to the fetus.

What is umbilical vein varix?

Focal dilation of the intra-abdominal portion of the umbilical vein.

What are the different grades in placental grading?

Grade 0 Grade I Grade II Grade III

What are cotyledons?

Groups or lobes of chorionic villi in placenta

What is the most common tumor of the umbilical cord?

Hemangioma (although it is rare)

What are the sonographic findings for Placenta Abruption?

Hematoma located either at the edge of the placenta or between the placenta and the myometrium.

What might cause a false positive for Placenta Previa?

If the maternal bladder is fully distended. If there is a Myometrial contraction that occurs in the lower uterine segment.

Why is anterior placenta previa linked with placenta accreta?

If there is a history of a previous C section. The placenta may attach to the scar from the c section

What is an elevated S/D ratio associated with?

Increased placental resistance and an increase risk of perinatal mortality and morbidity

When is Placenta Previa usually diagnosed and why?

It is not routinely diagnosed until the late second or third trimester. This is because of the growth of the uterus, the placenta has the potential to migrate away from the cervix.

What are uterine synechia and what causes them?

Linear bands of scar tissue within the uterus. They are a result of intrauterine adhesions. They can result from uterine surgery.

What is the most common placental hemorrhage identified with sonography?

Marginal abruption, also referred as subchorionic hemorrhage

What is the normal measurement for the Max Vertical Pocket?

Measure at least 2cm with a normal range of 2-8cm.

What are the sonographic finings for Grade II Placenta?

Moderate indentations on the chorionic plate with "Comma like" Calcifications in the placental substance

Placenta previa is discovered more often in women with a history of what?

Multiparity Advanced maternal age Previous abortion Cesarean section

Where are Allantoic cysts most often found?

Near the fetal abdomen

What is a deficient amount of amniotic fluid termed?

Oligohydramnios

What are umbilical cord cysts associated with?

Omphalocele Aneuploidy

If the placenta implants in the lower uterine segment what will this often lead to?

Placenta Previa

What is a common cause of painless vaginal bleeding in the second and third trimester?

Placenta Previa

What is the sonographic appearance of Complete Previa?

Placenta covers the internal os completely

What is the sonographic appearance of Marginal previa?

Placenta lies at the edge of the internal os

What is the sonographic appearance of Partial previa?

Placenta partially covers internal os

What is another term used for Venous Lakes?

Placental Lakes Maternal Lakes

What is the sonographic appearance of Low-lying previa?

Placental edge extends into the lower uterine segment but ends more than 2 cm away from the internal os.

What is Placentomegaly?

Placental enlargement

What is an excessive amount of amniotic fluid termed?

Polyhydramnios

What are Venous Lakes?

Pools of maternal blood within the placental substance, these are of little clinical significants.

What is Premature rupture of membranes ?

Premature rupture of the amniotic sac prior to the onset of labor.

What is Placental Abruption?

Premature separation of the placenta from the uterine wall before the birth of the fetus, thus causing hemorrhage

What are the sonographic findings for Grade III Placenta?

Prominent indentations in the chorionic plate that extends to the basal layer with diffuse echogenic and anechoic areas noted within the placental substance.

What happens to the S/D ratio with gestational age?

S/D ratio will decrease with advancing gestation.

How should the placenta be evaluated with sonography?

Should be evaluated after 20 weeks with an empty maternal bladder using a transabdominal approach, although transvaginal and translabial scanning is beneficial as well.

What is the sonographic appearance of Hemangioma?

Solid hyperechoic mass near umbilical cord insertion into the placenta

What does a Chorioangioma look like on ultrasound?

Solid hypoechoic or hyperechoic mass within the placenta.

What are the sonographic findings for Grade I placenta?

Subtle indentations on the chorionic plate, with some small calcifications within the placental substance

Fetal well-being can be assessed by using pulsed doppler of the umbilical cord and measuring what?

Systolic to Diastolic ratio (S/D ratio)

What is Placenta Previa?

The placenta partially or completely covers the internal cervical os

What is grading of the placenta used for?

To predict fetal lung maturity by assessing the indentations and calcifications.

What does TORCH stand for?

Toxoplasmosis Other infections Rubella Cytomegalovirus Herpes Group of infections that can cross the placenta.

What is Nuchal Cord?

Umbilical cord around the fetal neck.

What are the sonographic findings for Grade 0 placenta?

Uninterrupted chorionic plate and homogenous placental substance

What could a Circumvallate placenta lead to?

Vaginal bleeding placental abruption

What are the two abnormal cord insertion sites?

Velamentous Cord insertion Marginal Cord insertion

What is Vasa previa often associated with?

Velamentous cord insertion and possibly a succenturiate lobe

If you see echogenic debris in the amniotic fluid, what might it be?

Vernix Meconium

How is nuchal cord confirmed with ultrasound?

With the use of color doppler This abnormality should be documented especially if additional signs of fetal distress are evident.

What is Vasa Previa?

complication of fetal vessels resting over the internal os of the cervix

What is the most common congenital infection?

cytomegalovirus

What is Vernix?

protective fetal skin covering

What is a Bilobed Placenta?

two equal sized lobes of the placenta

What is Placenta Increta?

"In"vasion of the placenta within the myometrium

What is Placenta Percreta?

"Pe"netration of the placenta through the serosa and possibly into adjacent organs.

What are the clinical findings of Placental Abruption?

-Abdominal pain(Often sudden onset) -Possible vaginal bleeding -Uterine contraction -Uterine tenderness

What are some fetal malformations and complications that are associated with oligohydramnios?

-Bilateral Multicystic dysplastic kidney -Bilateral renal agenesis -Infantile polycystic kidney disease -Intrauterine growth restriction -Posterior urethral valves -Premature rupture of membranes (PROM)

What are some fetal malformations and complications that are associated with Polyhydramnios?

-Cardiac and or chest abnormalities -Chromosomal Abnormalities -Duodenal atresia -Esophageal atresia -Gastroschisis -Neural tube defects -Omphalocele -Rh incompatibility -Twin-Twin transfusion syndrome

What are the four types of Placenta Previa>

-Complete (Total) Previa -Partial Previa -Marginal Previa -Low-lying Previa

What are the functions of the placenta?

-Gas Transfer -Excretory functions -Water balance -pH maintenance -Hormone production -Defensive barrier

What is the umbilical cord comprised of?

-Two arteries, one vein -Surrounded by Wharton Jelly -All of which is covered by a single layer of amnion