Fetal Environment & Maternal Complications

Clinical findings of placental abruption:

1. Abdominal pain (often sudden onset) 2. Possible vaginal bleeding 3. Uterine contractions 4. Uterine tenderness

What are the 3 parts of the placenta?

1. Chorionic plate 2. Placental substance 3. Basal layer or Basal plate

Sonofindings of placental abruption:

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

Sonofindings of Vasa previa:

1. Identification of vessels over the internal os of the cervix with the use of Color Doppler 2. Velamentous cord insertion

Sonofindings of uterine synechia(e):

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

Sonofindings of placenta accreta, increta, percreta:

1. Placenta previa (frequent associated finding) 2. Loss of the normal hypoechoic interface

Clinical findings of chorioangioma:

1. Possible elevation in maternal serum alpha- fetaprotein

Clinical findings of Placenta previa:

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

Clinical findings of placenta accreta, increta, percreta:

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

Sonofindings of chorioangioma:

1. Well-circumscribed solid hypoechoic or hyperechoic mass within the placenta

When will a definite placenta be identified sonographically?

10-12 weeks

The placenta consist of how many cotyledons?

10-30

The thickness of the placenta should not exceed how many cm?

4 cm

How much does the placenta normally weigh and what's its diameter?

450-550 grams Diameter is 16 to 20 cm

Possible causes for thick placenta:

Diabetes mellitus Maternal anemia Infection Fetal hydrops Rh isoimmunization Multiple gestations

Possible causes for thin placenta:

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

Which is the most common placental hemorrhage identified with sonography?

Marginal abruption

Sonographic appearance of Grade II placenta:

Moderate indentations in the chorionic plate with "comma-like" calcifications in the placental substance

Marginal placenta previa sono appearance:

Placenta lies at the edges of the internal os

A condition that is defined as the abnormal adherence of the placenta to the myometrium in the area where the decidua is either absent or minimal is termed?

Placental accreta

Low-lying placenta previa sono appearance:

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

Partial placenta previa sono appearance:

Placental partially covers the internal os

Sonographic appearance of 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

Sonographic appearance of Grade I placenta:

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

Sonographic appearance of Grade 0 placenta:

Uninterrupted chorionic plate and homogeneous placental substance

The vessels of the umbilical cord are surrounded by a gelatinous material called?

Wharton jelly all of which is covered by a single layer of amnion

Succenturiate lobe are?

additional smaller lobes located separate from the main segment of the placenta

Placenta accreta is when there is:

adherence of the placenta to the myometrium

What is the most common location for an chorioangioma?

adjacent to the umbilical cord insertion site at the placenta

The placenta should be evaluated for placenta previa after 20 weeks with:

an empty maternal bladder using a trans abdominal approach, because the fully distended bladder may lead to a false-positive dx of the placenta previa

How do venous lakes appear sonographically?

anechoic or hypoechoic areas & may contain swirling blood

Where is the placental substance located?

between the chorionic plate and the basal layer

What type of placenta consists of 2 separate discs pf equal size?

bilobed placenta

The placenta is derived from:

both fetal & maternal cells

What is the preferred method of delivery when a placenta previa is present?

c-section because both fetus & mother have increased risk of death

What may be seen in the placenta with advancing gestation?

calcifications and indentations within the basal and chorionic plates

What is the most common placental tumor?

chorioangioma

What is the fetal contribution of the placenta?

chorion frondosum (derived from blastocyst & containing the chorionic villi )

An abnormally shaped placenta caused by the membranes inserting inward from the edge of the placenta, producing a curled up placental contour is termed?

circumvallate placenta

Placental abruption can be further described as:

complete partial marginal

The placenta has groups or lobes of chorionic villi which are termed?

cotyledons

What is the maternal contribution of the placenta?

decidua basalis (the endometrium beneath the developing placenta)

As a result of the abnormal adherence of the placenta, the placenta does not ______ at birth.

detach

How does a placenta appear sonographically?

echogenic thickening surrounding part of the gestational sac

Where can a retroplacental hematoma be located?

either between the placenta and myometrium or under the chorionic membrane

In later pregnancy the placenta also produces:

estrogen and progesterone taking over the function of the corpus luteum

In vasa previa, if the vessels rupture, it will then lead to:

exsanguination of the fetus

What maintains the corpus luteum of the ovary?

hCG

Depending on the amount of invasion or penetrations of the placenta into the myometrium, the patient could suffer from:

heavy bleeding at delivery & possible uterine rupture

A complete abruption is the most severe, often results in the development of a:

hematoma, which is located between the placenta and the myometrium

What are maternal conditions that are linked to the development of placental abruption include:

hypertension, preeclampsia, cocaine use, cigarette smoking, poor nutrition, & trauma

What are the 3 different terms associated with placental accreta:

i.placental accreta ii.placental increta iii.placental percreta

When is placenta previa discovered more often in women with history of?

in women with history of multiparty, advanced maternal age, previous abortion, & prior cesarean section

Uterine synechiae are a result of:

intruterine adhesions, as seen with Asherman syndrome, that result from uterine surgery

Increta and percreta can be dx based on the amount of:

invasion & if there is a breach of the serosal layer of the UT

Placenta increta is when there is:

invasion of the placenta within the myometrium

What is the basal layer of the placenta?

is the area adjacent to the uterus

Sonographic appearance of placenta increta:

loss of normal hypoechoic interface between the placenta and myometrium with invasion into the myometrium

Sonographic appearance of placenta percreta:

loss of normal hypoechoic interface between the placenta and myometrium with penetration beyond the serosa

Sonographic appearance of placenta accreta:

loss of normal hypoechoic interface between the placenta and the myometrium

Both a thin & thick placenta are associated with:

maternal and/or fetal abnormalities

What else could cause a false-positive placenta previa?

painless myometrium contractions that occur in the lower uterine segment (they resolve as sonography continues)

Placenta previa is a common cause of ___________ _________ in the 2nd & 3rd trimesters.

painless vaginal bleeding

Placenta percreta is when there is:

penetration of the placenta through the serosa and possible into adjacent organs

Marginal abruptions lies at the edge of the ____________.

placenta

What is a vital organ to the fetus during pregnancy?

placenta

What produces hCG?

placenta

Complete(total) placenta previa sono appearance:

placenta covers the internal os completely

When implantation of the placenta occurs within the lower uterine segment it leads to:

placenta previa

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

placental abruption (abruption placentae)

A thick and large placenta is termed?

placentomegaly

Usually chorioangioma does not carry any risks to the mother/ fetus, although larger chorioangioma have been associated with:

polyhydramnios, intrauterine growth restrictions(IUGR), & fetal hydrops

Uterine synechiae have be associated with:

premature rupture of membranes, premature delivery, & placental abruption

The placenta becomes the means of ________________ for the fetus.

respiration

Partial abruption often results in only a few centimeters of ___________.

separation

What is exsanguination of the fetus?

severe blood loss

Marginal abruption is also known as?

subchorionic hemorrhage

What is another name for an accessory lobe of the placenta?

succenturiate lobe

With placenta percreta the placenta can even invade:

the UB, thus causing urinary complications

What is the Chorionic plate of the placenta?

the element of the placenta closest to the fetus

The Placental substance contains?

the functional parts of the placenta

Placenta previa is evident when the placenta covers:

the internal os of the cervix

What is prone to happen with vasa previa?

the vessels are prone to rupture as the cervix dilates

Amniotic bands are typically _______, or may not be seen & are associated with _________ ____________.

thinner fetal anomalies

What is one major function of the placenta?

to act as an excretory organ for the fetus, performing imperative changes of waste products & gases with valuable nutrients & oxygen from the mother.

The correlation with C-section is theorized to be the result of ________ ______ formation from surgery, with subsequent implantation of the next placenta in that area.

uterine scar

With Placental accreta the placenta may attach to:

uterine scar following a previous c-section and/or uterine surgery

What are linear bands of scar tissue within the uterus?

uterine synechiae

What is referred to as amniotic sheets?

uterine synechiae

A circumvallate placenta may lead to:

vaginal bleeding & placental abruption

The complication of fetal vessels resting over the internal os of the cervix is referred to as?

vasa previa

Vasa previa is often associated with:

velamentous cord insertion & possibly a succenturiate lobe

How many vessels are in the umbilical cord?

(3) 2 arteries and 1 vein

Functions of the placenta:

*Gas transfer *Excretory function *Water balance *pH maintenance *Hormone production *Defensive barrier