maternal portion

the decidual reaction that occurs between the blastocyst and the myometrium

this part unites with the chorion to form

 the placenta

• chorion
• amnion
• yolk sac
• allantois

materal portion formed by the

 endometrial surface

characterized by transformation of cells into glycogen and lipoid cells

occurs in response to ovarian hormone

• decidua basalis
• decidua capsularis
• decidua parietalis

The placenta is differentiated into what

 three areas:

decidua vera

(parietalis)

major functioning unit of placenta;

maternal blood enters te spaces here

• metabolism
• endocrine secretion
• transfer

oxygen in maternal blood diffuses across the placnetal membrane into fetal blood by diffusion

Carbon dioxide passes in the opposite direciton

hormonal production

(endocrine function)

• placental defects
• net effect is that there is a reduction between the fetal and maternal blood

• syncytiotrophoblast
• cytotrophoblast

contains the developing embryo and the

amniotic fluid

remains attached to the embryo at the cord insertion site and ultimately covers the umbilical cord

• chorion frondosum
• chorionic and amniotic membranes
• skin
• respiratory tract
• urinary tract

• gastrointestinal system
• amniotic-chorionic interface

• electrolytes
• water
• urea
• creatinine

cytotrophoblastic shell and

achoring villi

• Rh sensitization
• diabetes of pregnancy
• congenital anomalies

enlarged placentas are most often associated

with what?

prior uterine surgery and

 placenta previa

• advanced maternal age
• multiparity
• prior cesarean section
• uterine surgery

• premature delivery
• life-thretening maternal hemorrhage
• increased risk of placenta accreta
• increased risk of postpartum hemorrhage
• IUGR

earliest placental grade; smooth, well-defined chorionic plate with homogeneous placental tissue

typical <28 weeks

characteristic undulation (indentation) of the chorionic plate; spotlike densities dispersed throughout the tissue

after 34 weeks

Indentations of the chorionic plate; linear commalike densities extending from the chorionic plate into the placental substance but not reaching the basal plate

after 36 weeks

highest grade; comma like densities reach basal plate and placental septae are depositied with calcium surrounds the placental lobes

after 38 weeks

• maternal cigarette smoking
• thrombotic disorder or medicines used to treat them

Clinical problems of what?

• bleeding will occur when uterus contracts and placenta separates before it is due to
• pt has painless bright red bleeding

• valamentous insertion
• succenturiate lobe with connecting vessels over os

Two most common occurances for

vasa previa are:

bleeding from the placenta due to any cause

(more common than abruption)

seperation of placenta from myometrium before term delivery; mortality rate 20-60%

Clinically-preterm labor, vaginal bleeding, abdominal pain, fetal distress, or demise

Trophoblastic disease

(molar pregnancy)

Pt. has extreme nausea and vomiting, extremely elevated hCG. vag. bleeding, size larger than dates, preeclampsia, no identifiable fetal parts, inhomogeneous texture

Bilateral theca lutien cysts

second most common benign tumor

 of placenta

• maternal diabetes
• maternal anemia
• alpha-thalassemia
• Rh sensitivity
• Fetomaternal hemorrhage
• chorionic intrauterine infections
• twin-twin tranfusion syndrome
• congenital neoplasms
• fetal malformations

• IUGR
• intrauterine infection
• chromosomal abnormality

attachmen of the placental membranes to the fetal surface of the placenta rather than to the placental margin

placntal margin is folded, thickened, or elevated with underlying fibrin and hemorrhage

• oligohydramnios
• resticted space
• intrinsic fetal anomaly
• tethering of the fetus by amniotic band
• inadequate fetal descent
• cord compression
• fetal distress

• >80 cm
• polyhydramnios
• nuchal cord
• true cord knots
• cord compression, presentation, and prolapse
• cord stricture or torsion

• artificial rupture of membranes
• disengaging the head
• version and extraction

• membranes
• umbilical cord
• lungs
• skin
• kidneys

• protect fetus
• allows fetal movement
• prevents the amnion from connecting to fetus
• allows symmetrical growth
• maintains uterine temperature
• reservoir

• CNS disorders causing depressed swallowing
• GI abnormalities often atresia of esophagus, stomach, duodenum, small bowel
• fetal hydrops, skeletal anomalies

• IUGR
• fetal renal anomalies
• Premature rupture of membranes
• latrogenic causes