placenta

grade ___ : < ____ weeks uniform echogenicity, smooth ____________ _______

0 18 chorionic plate

grade____: ______ - _____ weeks : occasional parenchymal calcification /______________ areas

1 18 29 hyperechoic

a marginal cord insertion is within _____ of the placenta edge?

10 mm

Normal term placenta has several characteristics at delivery -Measures about ____ to ____ cm in diameter -Discoid in shape -Weighs about 600 g -Measures <___ cm in thickness

15 20 4

Placenta Thickness Usually ____ to ____ cm in fetuses >23 weeks Normal placenta rarely exceeds ____ cm Measure AP

2 3 4

Sonographic Evaluation of the Normal Placenta identified as early as ___ menstrual weeks relatively _______________ mid-level gray appearance between ___ and _____ weeks smooth borders

8 homogenous 8 20

What could cause a false positive diagnosis of placenta previa?

An overdistended maternal urinary bladder

What is the difference between the chorion frondosum and chorion laeve?

Chorion frondosum: Forms fetal part of placenta; contains villi Chorion laeve: Nonvillious part of chorion around gestational sac

What is the fetal surface of the placenta called? What is the maternal surface called?

Chorionic plate: Fetal surface of placenta Basal plate: Maternal surface of placenta

what kind of placenta is this?

Circumvallate Placenta

what is the functional unit of the placenta? how many per placenta? These compartments are only visible from the ___________ side of the septa as the decidual septa do not project all the way to the chorionic plate

Cotyledon 12- 20 maternal

grade _____ : > ____ weeks : occasional basal calcification / hyper-echoic areas may also have comma type densities at the chorionic plate

II 30

grade ____: > ___ weeks significant basal calcification chorionic plate interrupted by indentations

III 39

Small Placenta ________ Intrauterine ____________ _____________

IUGR infection aneuploidy

What are the normal/abnormal AP measurements of the placenta?

Normal: 2-3cm Abnormal: > 4cm

Attachment of placental membranes to fetal surface of placenta rather than to underlying villous placental margin Associated with: _______ preterm ______ IUGR placental _________

PROM labor abruption

Chorionic villi Attach to myometrium without muscular invasion is called? 1 in 2500 deliveries

Placenta Accreta

Further extension of the chorionic villi Into the myometrium (Invade) ? Results from underdeveloped decidualization of endometrium High maternal mortality and morbidity associated with placenta _________/ precreta

Placenta Increta

Penetration of the chorionic villi through the uterus is called?

Placenta Percreta

What placental condition(s) presents with painless vaginal bleeding?

Placenta Previa Vasa Previa

what occurs when large fetal vessels run in fetal membranes across cervical os? -Vessels at risk of rupture and life-threatening hemorrhage -in some cases, there are absolutely no symptoms or signs to warn

Vasa Previa

Placental _____________ -Premature placental detachment -Occurs in 1 in _____ pregnancies -Bleeding in decidua _________ occurs with separation

abruption 120 basalis

Black Lambda Sign - Monochorionic "Black lambda" sign at monochorionic diamniotic twin pregnancy. It is a triangular space between the outline of the __________ _____ and the __________ _____

amniotic sac uterine wall

If ____________ and _______________ placenta does not appear to communicate, succenturiate placenta should be considered -Differentiate main lobe from accessory lobe by locating __________ ______insertion site

anterior posterior placental cord

The decidua capsularis and decidua parietalis join or are attached at the decidua __________ The double decidual sac sign is so named because of the sonographic appearance of 2 concentric rings around the gestation sac; this is a normal finding in _______ ___________

basalis early pregnancy

Embryogenesis- Decidual reaction that occurs between ___________ and ___________ Reaction occurring over blastocyst __________ to endometrial cavity Hormonal influence on uninvolved endometrial tissue

blastocysts myometrium closest

______________-closes over and surrounds the blastocyst ____________-results from hormonal influence on the uninvolved endometrial tissue; Reaction except for areas beneath and above implanted

capsurlaris parietalis

Mid-Placental Attachment of cord is usually near _______ of placenta

center

________________ -___________ vascular tumor of placenta -Most common "tumor" of placenta -Usually small When tumors are large (>5cm), complications may include polyhydramnios and fetal hydrops. -Vascular tumor of the placental tissue which occurs 1: _______ pregnancies. -Sonographic findings: usually ______________, well circumscribed placental mass, possibly near cord insertion site.

chorioangioma benign 5000 hyperechoic

Circumvallate/Circummarginate Placenta A ________________ placenta is diagnosed when the placental margin is folded, thickened, or elevated with underlying fibrin and hemorrhage. -Results in placental villi around border of placenta not covered by ___________ _______

circumvallate chorionic plate

Marginal Abruption -Most _________ type of abruption -Known as subchorionic bleeds -Hemorrhage results from tears of the marginal veins and represents "_____-_________" bleed. -Arises from edge of placenta, dissects beneath placental _____________ and is associated with little placental detachment

common low pressure membranes

_____________ abruptions: occurs in ____% of cases and hemorrhage is ___________ to uterine cavity. The detachment may be ___________ and the consequences are severe. May be diagnosed sonographically.

concealed 20 confined complete

PLACENTOMEGALY Gestational ___________ Maternal anemia Fetal __________ Rh sensitivity Fetomaternal _____________

diabetes hydrops hemorrhage

Twin Peak Sign (Lambda Sign) _______________ Best seen in the _______ trimester (between 10-14 weeks) The only absolute sign of dizygosity on ultrasound is documentation of different ____ fetuses.

dichorionic first sex

_____________ (fraternal twins) Derived from _____ zygotes Diamniotic/dichorionic/two placentas Occurs during first ___ days of gestation If di/di = 97% chance dizygotic

dizygotic two 4

Bladder Influence on Placental Position If maternal bladder full, cervix is falsely ____________ Normally implanted placenta may appear to be covering internal cervical os May give false impression of _________

elongated previa

____________- Waste products cross membrane from fetal blood and enter maternal blood. Excreted by mother's _________

excretion kidneys

_________ abruption: Blood drains through the __________ ___, and patient presents clinically with painful vaginal bleeding. Detachment is usually not as _________. If no blood remains in the retroplacental space, sonographic diagnosis is difficult.

external cervical os severe

Fetal Chorion- Chorionic plate: _________ surface of placenta -component is derived from the ___________ tissue Basal plate: ____________ surface of placenta -component derived from decidua ___________

fetal trophoblastic maternal basalis

The decidua capsularis is separated from the decidua parietalis by a small amount of _______ within the endometrial cavity. The decidua parietalis lines the ____________ cavity whilst the decidua capsularis encases the ___________ sac.

fluid uterine gestational

Acts as an immune shield between a mother and her baby; a baby is a combination of their mother's and father's genes. This means that a baby is a genetically _________ _______ within its mother and these normally are attacked by the body's __________ _________ (just like when an organ donor recipient rejects a transplanted organ).

foreign body immune system

Chorion _____________: Forms fetal part of placenta; contains villi (contact with decidua basalis) Chorion _________: Nonvillious part of chorion around gestational sac

frondosum laeve

____________ is the fetus' main source of energy and passes the placenta via simplified transport

glucose

Placental ____________ -Bleeding from placenta from any cause -More commonly seen than placental abruption -Echogenicity depends on ____ of the hemorrhage. -Acute bleed similar to echogenicity of ___________ -Subacute and chronic bleed becomes more ____________

hemorrhage age placenta hypoechoic

The maternal placental circulation may be reduced by a variety of conditions that decrease uterine blood flow, such as severe ____________, ________ disease, or placental __________. Placental defects can cause ________

hypertension renal infraction IUGR

placentomegaly 2 Chronic intrauterine ____________ Twin-twin transfusion syndrome ___________ _______ Chromosome abnormalities

infections partial mole

Placental ______ After ____ weeks' gestation, intraplacental sonolucenies and placental ____________ may begin to appear

lakes 20 calcifications

Battledore placenta (___________)

marginal

_____________: The placenta is next to cervix but does not cover the opening; placenta encroaching on not crossing the os ________: The placenta covers part of the cervical opening. _________: The placenta covers all of the cervical opening. __________: (not a type of previa) placenta in lower uterine segment within 2cm of internal os

marginal partial complete low-lying

Multiple factors associated with placenta previa Advanced __________ _____ Smoking Cocaine abuse Prior placental _______ Multiparity Prior cesarean section Uterine surgery Abnormally ________ ______

maternal age previa shaped uterus

The placenta produces hormones that allow a mother to maintain her pregnancy: -These hormones ensure that a mother doesn't go through her __________ _______ after she falls pregnant, so that her ________ is capable of maintaining a pregnancy. -Secretion of ______________, ______

menstural cycle uterus progestrone hCG

Insertion of Cord into Placenta Describe as : 1. 2. 3.

mid-placental marginal velamentous

Term ____________ used to describe how the placenta changes position within uterine cavity Placenta does not actually change location

migration

T Sign - ______chorionic In contrast the T sign refers to the appearance of the inter-twin membrane in a monochorionic twin pregnancy.

mono

Monozygotic (identical twins) If pre-implantation blastocyst splits during the first week of gestation (after chorion/trophoblast forms but prior to the formation of the amnion): ______chorionic/____amniotic one placenta 2 sacs thin membrane

mono di

Monozygotic (identical twins) If blastocyst splits during the second week of gestation (after chorion differentiates and after amnion forms): _____chorionic/______amniotic one placenta one sac "Unlucky 13"

mono mono

_______________ (identical twins) Derived from _____ zygote If morula divides during first four days of gestation (prior to formation of trophoblast chorion): Diamniotic/dichorionic-with or without fused placentas 1 or 2 placentas 2 sacs Thick membrane

monozygotic one

The double decidual sign consists of the decidua __________ surrounding the decidua ______________ with the gestation sac encased within the Decidua capsularis.

parietalis capsularis

Placental Invasion Abnormal _______________ of placental tissue beyond _____________ lining of uterus the association of placenta __________ reflects the thin, poorly formed _________ of the lower uterine segment that offers little resistance to deeper invasion by the trophoblast Previous cesarean scar permits trophoblastic invasion.

penetration endometrial previa deciduas

Implantation of placenta over internal cervical os is called? Normally implants in body or fundus of uterus In one of _____ pregnancies Risk increases with history of cesarean delivery

placenta previa 200

Functions of the Placenta- site of conversion ___________ cells migrate to the blood vessels of a mother's uterus and adapt them to accommodate the considerable __________ in blood flow to the uterus that occurs during pregnancy. Conversion of fetal __________ to __________

placental increase steriods estrogen

-Refers to separation of normally implanted placenta prior to term delivery -Symptom is abdominal pain, with or without bleeding this is describing?

placental abruption

An early progression to a grade III placenta is concerning and is sometimes associated with ____________ ______________

placental insufficiency

Sagittal view of the uterus reveals a _________ ______ placenta

posterior fundal

Decidua=____________ _____________, endometrial cells transformed to glycogen and lipoid cells in response to ovarian hormones. Basalis-develops where the ___________ implants; maternal contribution to the placenta

pregnant endometrium blastocysts

Complications of placenta previa ____________ delivery Maternal hemorrhage Increased risk of ____________ ___________ Increased risk of postpartum ____________ IUGR

preterm placental invasion hemorrhage

It is more common in women who have: •Abnormally shaped uterus •Many __________ ____________ •Multiple pregnancy (twins, triplets, etc.) •Scarring on the lining of the uterus, due to history of surgery, c-section, previous pregnancy, or abortion

previous pregnancies

Site of Exchange _____________ - Transfer of oxygen from maternal blood across the placental membrane into fetal blood is by diffusion. Carbon dioxide passes in the opposite direction. The placenta acts as "_______ ________."

respiration fetal lungs

Transverse view of the uterus demonstrates a ______ side wall placenta that extends along the _________ wall of the uterus

right anterior

Retroplacental Abruption -Results from rupture of _______ arteries and is "high-pressure" bleed -Associated with HTN and vascular disease -___________ between placenta and uterus -If blood remains retroplacental, patient may have no ___________ __________

spiral hematoma vaginal bleeding

Presence of one or more accessory lobes connected to body of placenta by placental vessels is called?Occurs in ____% to ____% of pregnancies

succentiriate lobe 3 6

To better demonstrate internal cervical os when scanning transabdominally: Tilt patient in slight _____________ position (head lower than body) Relieve pressure of uterus on lower uterine segment

trendelenburg

Fetal-Placental-Uterine Circulation Internal Iliac Artery ________ Artery Arcuate, Radial, Spiral Arteries Intervillous Space for exchange (________ ______) Returns thru ________ network

uterine enters cord venous

Sonographic findings of placental abruption: -elevation of the placenta from the __________ _____, retroplacental fluid collection of varying ______________ (depending on age) - most likely hypoechoic

uterine wall echogenicity

Something expectant mothers should watch for, especially in their second and third trimesters, is the sudden onset of painless vaginal bleeding. The lack of pain is usually a signal that what is present?

vasa previa

Most common causes of vasa previa _________________ insertion of umbilical cord into placental membranes, which cross over the cervix ________________ lobe present, and connecting vessels traverse the cervix

velamentous succenturiate

Nutrition - _________, inorganic salts, _______________, fats, ____________, and vitamins pass from maternal blood through the placental membrane into fetal blood.

water, carbohydrates, proteins,

Velamentous Cord ( gross picture) Vessels not protected by _________ ______ (rupture) Cord inserts into fetal membranes Travels between _________ and __________ to placenta

whartons jelly amnion chorion