The Placenta and Umbilical Cord Flashcards
What is the role of the placenta?
growth, development, and maturation of a pregnancy
What is the placenta evaluated for?
size and shape, number, texture, location (relative to internal cervical os)
The placenta comes from?
The trophoblast becomes the chorion then the placenta
The outer trophoblast produces?
hCG
How does hCG contribute to pregnancy?
stops period by telling corpus luteum to thicken endo
The maternal side of the placenta is the?
basal layer
The fetal side of the placenta is the?
chorionic plate
Which part of the decidua does the chorion frondosum contact?
decidua basalis
The smooth chorion contacts?
decidua capsularis
What is a subchorionic hematoma?
bleed below chorionic cavity
What is ABS?
amniotic band syndrome; rupture of amnion causing bands that can wrap around or attach to fetal parts
ABS can lead to?
constrictures, deformations (clefts), amputations,
How do amniotic bands appear sonographicall?
thin and echogenic
What are amniotic sheets?
adhesions or fibrous scar tissue inside the myometrium
Amniotic sheets are also called?
amniotic folds or synechiae
True or False: Amniotic sheets can lead to fetal deformities
False
How can you determine whether or not there is an amniotic sheet?
color doppler (muscle will light up)
What can cause synechiae?
infection (STD), trauma, D&C
How do amniotic folds appear sonographically?
thick, echogenic, color flow
What are the main functions of the placenta?
source of nutrients, exchange of gases and waste products, hCG
The placenta should not exceed what thickness?
4 cm
A large placenta can be caused by?
diabetes
A small placenta can be caused by?
smoking
What is placental trophotropism?
when the uterus grows and the placenta “moves” with it; placenta does not actually move within cavity
What is the reason that placenta previa is not a concern in an early pregnancy scan?
placental trophotropism
What are the locations a placenta can have in a sagittal plane?
anterior, posterior, fundal, previa
What are the locations a placenta can have in a transverse plane?
anterior, posterior, right, left
A grade 2 placenta has?
basal linear echoes
A grade 3 placenta has?
prominent, calcified cotyledons