Repro: Placenta Pathology

Front 1

Placenta parts

Back 1

Embryo surrounded by a fluid filled sac (amniotic sac) and connected by the umbilical cord to the rest of the placenta

Amniotic sac inner epithelial lining is amnion, outer lining is chorion

Front 2

Vessels in umbilical cords

Back 2

Single umbilical vein bringing oxygenated blood and nutrients to fetus

Two umbilical arteries transport deoxygenated blood and waste products from the fetus to mother

Umbilical vessels branch and terminate in placental chorionic villi that embed into endometrium, Villi erode into arteries from endometrium allowing maternal blood to flow around the chorionic villi.

Source of oxygen/nutrient/waste exchange

Front 3

Exchange of maternal and fetal blood location

Back 3

surface of chorionic villi through the trophoblast

NO mixing of blood except in trauma

Front 4

Normal placenta shape, size, surfaces

Back 4

Disk shaped, 500g, 15x15x3cm

normally umbilical cord located at center

Fetal side - smooth, translucent with fetal vessels branching from main umbilical cord vessels

Maternal side - many nodules, clotted bloood from detachment and delivery

Front 5

Layers of chorionic villi

Back 5

Translucent mesenchymal stroma, surface lined by 2 layers of epithelium (trophoblasts)

a) cytotrophoblast - inner layer, small cells with single nuclei, NO hormonal production
b) syncytiotrophoblast - outer layer, multinuclear cells - production of hCG and hPL (human placental lactogen)

Front 6

Normal placenta implantation
a) Placenta previa
b) Placenta accreta
c) Placenta increta
d) Placenta percreta
e) Abruptio placenta

Back 6

Normal - placenta attached to upper part of uterus, chorionic villi invade only endometrium

a) Placenta previa - placenta in lower uterine segment or covering cervical os, prevents normal delivery, US can see, C-section to deliver
b) Placenta accreta - villi invade the superficial myometrium
c) Placenta increta - villi invade deeper into mid myometrium
d) Placenta percreta - villi invade through entire myometrium and extend into serosa (possible rupture of uterus with bleeding)
e) Abruptio placenta - premature detachment of placenta prior to delivery with formation of a hematoma

Front 7

What is main cause of villi invasion

Back 7

Endometrium sometimes called decidua in a pregnant woman b/c progesterone causes cells to be eosinophilic, larger and almost look like squamous cells

C-section and D&C can leave parts of uterus without endometrium and if villi are in that area they can easily invade. During delivery it is harder to detach placenta from this area and may bleed heavily, be indication for hysterectomy

Front 8

Retroplacental hematoma

Back 8

Cause unknown (may be trauma or genetic), placenta detaches and blood accumulates between placental and decidua. Functionality of placenta limited to area not affected by hematoma

Leads to anoxia of fetus and maternal blood loss

Front 9

Placental Infarcts Acute vs Old

Back 9

Acute - red, ill circumscribed, soft
Old (healed) - white, well circumscribed, firm, term placenta has small, old infarcts at margin in 25% of normal.

If there are massive infarctions or if occur in first trimester may have lasting effects (cerebral injury, growth retardation, or fetal demise)

Front 10

Preeclampsia, changes

Back 10

HTN and proteinuria in pregnant women

Infarction risk, changes in vessel walls, eosinophilic and necrotic look. Thrombi risk in endothelium

Front 11

Pathologies of Umbilical Cord

Back 11

Normal cord has 2 arteries taking waste and deoxygenated blood away from fetus. One vein bringing oxygenated blood and nutrients to fetus. Surrounded by mesenchymal Wharton's jelly to protect vessels from rupture or injury and amnion covers surface

Pathology
a) Single umbilical artery - fetus had 2 but one atrophied or destroyed. Fetus can survive however fluid will not be efficiently removed and may cause cardiac overload. Can cause urinary tract malformation

b) Umbilical cord insertion - Normally placenta has central or paracentral insertion of umbilical cord. Abnormal insertion of the cord in membranes (velamentous insertion) where it is no longer protected by Wharton's jelly. Prone to injury and hemorrhage

c) Umbilical Knots - cord is long, can strangle fetal neck, fetal movement can cause knots. Usually Wharton's jelly will protect

Front 12

False knot

Back 12

Protrusion of the cord vessel or Wharton's jelly may resemble knot

Front 13

Short umbilical cord effect

Back 13

<32cm

Limits movement of fetus and may cause deformities

Front 14

Cord tangling

Back 14

Complication of monozygotic twin pregnancy in a common amniotic sac. Results in hypoxia or fetal death

Front 15

Infection of Placenta and Fetus
a) Ascending infection
b) Hematogenous infection
c) Contact infection

Back 15

a) Ascending infection - infection caused by bacteria that pass from vagina or cervix into uterus and results in acute chorioamnionitis and funisitis (umbilical cord)

b) Hematogenous infection - organism from circulating maternal blood passes to placenta/fetus causes Villitis of chorionic villi chronically.

c) Contact infection - transmission of the infection to infant during vaginal delivery, NOT associated with placenta inflammation

Front 16

Chorioamnionitis, cause,

Back 16

MAIN CAUSE of preterm birth and second trimester abortion

Cause: Group B strep (>50% of prenatal infections), E. coli, Bacteroides, Ureaplasma urealytica, Mycoplasma hominis, Fusobacterium nucleatum, Candida.

Histology - Neutrophilic inflammation

Often due to ascending inflammation from vagina or cervix into uterus

Front 17

Villitis, Cause, Appearance

Back 17

Hematogenous infection from mother can be passed to placenta/fetus and cause chronic chorionic villi inflammation

Histology - acute inflammatory villi with fibrin and granulomas.

Gross - Placenta is opaque, green discoloration, smells badly

Cause - usually unknown. May be TORCH infection

Front 18

TORCH infections

Back 18

Toxoplasma
Other: syphilis, TB, listerosis
Rubella
CMV
Herpes simplex (mostly during vaginal delivery)

Front 19

Common contact infections

Back 19

HIV, HSV, group B strep, HBV, gonorrhea, chlamydia, HPV

Prevent with antimicrobial treatments, C-section and newborn screen

Front 20

Multiple Gestation, What increases incidence

Back 20

Can be any number of fetuses

Monozygotic (identical) - fertilization of one ovum; 1/3 of all twinning events are RANDOM OCCURENCE. Share amnioitic cavity, umbilical cords may tangle causing fetal demise

Dizygotic - fertilization of two or more ova; accounts for 2/3 of all twins. Incidence increases with parity, increased maternal age, family history and assisted reproduction

Front 21

Hydatidiform mole, complete vs partial and measuring, Presentation, Gross, histology, invasive mole

Back 21

Arise from CHORIONIC VILLI

Complete mole - no maternal genetic material (egg has no material), can have two sperm enter egg or one sperm enter and duplicate DNA. Ends with diploid cell with only paternal chromosomes (XX or YY). 1-2% risk of choriocarcinoma, HIGH hCG levels

Partial mole - egg has maternal genetic material and either 2 sperm or one diploid sperm leading to 69XXY genotype. hCG still elevated more than normal pregnancy but not to complete mole levels

Presentation - larger uterus than normal gestational age because of abnormal growth in chorionic villi

Gross - endometrial curettage shows grape-like structures filled with fluid

Histology - enlarged chorionic villi of various sizes with fingerlike projections and trophoblastic proliferation

Invasive mole - hydatidiform mole is not completely removed by D&C, villi invade to myometrium. Harder to remove atypical villi by curettages, will have continued hCG elevation

Front 22

Choriocarcinoma, Gross and Histology

Back 22

Tumor arising from TROPHOBLASTS (not chorionic villi like moles)

Can develop in pregnancy or non-pregnant males and females

Gross - brown, hemorrhagic, soft necrotic tumor, aggressive invasion to uterus

Histology - atypical trophoblastic proliferation, large cells with mitoses and abnormal nuclei, Hemorrhage and necrosis. Stains with hCG, NO CHORIONIC VILLI

Front 23

Infection most commonly causing chorioamnionitis, villitis

Back 23

Chorioamnionitis - Group B strep

Villitis - Toxoplasmosis