Flashcards in Placenta Deck (37)
What is the earliest the placenta is seen on US
Weighs 500-600 g
Chorionic plate on fetal side
Basilar plate on maternal side adj to retroplacental complex
Major functioning unit of placenta
Protection, nutrition, respiration, excretion
Cord should insert
May ID by 8-10 wks as
< or = 5 cm
Visualize retroplacental complex by
0: smooth no Ca+, homo
1: sm Ca+ randomly dispersed
2: Ca+ of basilar plate
3: Ca+ intentions of pl extending from chorionic plate to basilar plate. See lobes.
Grade 3 < 34 wks inc risk for
Grade/calcification delay with, accelerated with
Maternal diabetes, Rh blood
HTN, IUGR, smoking, AMA
2 lobes both equal in size. Cord inserts between both lobes.
Succentureate Lobe/Accessory Lobe
1 or more small lobes connect to main placenta. If retained after delivery, may hemorrhage. Connecting vessels may overly internal os.
Doughnut, ring shape
Covers surface of sac, very thin.
Placenta Diffusa: rare, covers most of uterine wall.
Placenta extends beyond chorionic plate. Curled up margins.
Assoc with bleeding and preterm.
Amniotic sheets/folds, thick band with color flow
Amniotic band syndrome/ ADAM complex
Rare, thin membrane of amnion freely cross sac. May entangle fetus. Risk of ABS with early amniocentesis
Placenta size increase with
Diabetes, Rh, CMV, chorioangioma, abruption, twins, hydrops, fetal anemia, triploidy, maternal anemia
Placental size decrease
IUGR, preeclampsia, infarction, toxemia, maternal cardio renal disease, trisomies, severe diabetes, chronic infection, htn
Placental covers internal os
Complete/Total: covers both sides of cx canal
Low lying: within 2 cm of io
Do c section
Painless vag bleeding
Inc with AMA, smoking, multiparity, c sections, low ut scars, trauma, hx D&C, twins, abnl fetal lie
Premature delivery, maternal hemorrhage, placenta accreta, post partum hemorrhage, IUGR,
Over distended bladder cause false positive
Hypertrophy of upper part & atrophy of lower part bc LUS isn't as vascular
Vessels overly internal os. High fetal mortality. C section.
Premature placenta detachment
Knife like pain. Bleeding, shock, preterm labor, fetal distress/demise
Assoc with HTN, cocaine, vasc disease, trauma, preeclampsia, short umb cord, fibroids, previa
Hematoma. Retroplacental hemorrhage
Abnl placental attachment
Accreta: on myometrium, mildest, most common
Percreta: into myometrium
Increta: through serosa, rarest
Hx of c section + previa = 25% chance
MC placental tumor
1%, benign vasc tumor, inc MSAFP, through fetal surface of placenta, solid, complex, usually near cord insert.
Large leads to hydrops, polyhydramnios, hemorrhage, premie, IUGR, demise, cardiomegaly
Rare, usually benign, malignant very bad, complex mass with shadow.
Mets to placenta
From mom: Melanoma, Breast cancer, lung cancer. Lung most common.
Fetal: neuroblastoma, leukemia
2 arteries, 1 vein. Mickey Mouse, surrounded by Wharton's Jelly for protection.
Length: 55cm at term.
Should insert centrally
Marginal cord insertion / battledore placenta
Inserts within 2 cm of edge of placenta. (Inside placenta)
Cord inserts a distance away from placenta (cord inserts on membrane)
Difficult to ID, hazardous if construction occurs.
Cord around fetal neck, 20% of deliveries. Nurse unwraps cord when delivering.
Part of cord presents before fetus. May compromise circulation. Dangerous at birth.
Single Umbilical Artery / 2 Vessel Cord
1 artery at bladder. Mickey Mouse missing ear trvs.
Inc risk IUGR, tri 18, 13, 21
Benign vascular hyperechoic umbilical cord mass