Obstretic Pathology 1 Flashcards
_____ is a temporary organ connecting
fetus and mother providing
the equivalent of respiratory
(and renal) services.
Placenta
_____ is a membranous sac surrounding
fetus containing serous fluid essential
for fetal development
Amnion
_____ is a plate-shaped tissue under part
of amniotic sac containing fetal blood
vessels that branch into villi projecting
into space filled with maternal blood
chorion
____ is the outer layer of blastocyst
(from fertilized ovum) that implants in
uterus and forms placenta
trophoblast
_____ is the outer layer of placenta that
normally peels off myometrium and
sheds with placenta
Decidua
\_\_\_\_\_\_ are syncytium of cells forming outer covering of chorionic villi, which thin out their cytoplasm and let their clumped nuclei hang off villi in “syncytial knots” to minimize diffusion barrier
syncytiotrophoblast
In the first trimester, what is the chorionic villi covered by?
Double layer of inner and outer cytotrophoblast
In the 3rd trimester, what happens to the covering of chorionic villi?
more blood vessels, less interstitium, thinner trophoblast covering
How often to ectopic pregnancies occur and where?
1 in ever 150; 90% within fallopian tube
Pathogenesis of ectopic pregnancy
up to 50% from scarring from previous infection of tube. Other causes are adhesion from appendicitis, endometriosis, or surgery
What is the most common presentation of ectopic pregnancy?
acute severe abdominal pain due to fallopian
tube rupture and pelvic hemorrhage,
about 6 weeks after last menses
Can lead to hemorrhagic shock, death
How is a diagnosis of ectopic pregnancy made?
history, physical (signs of peritonitis), ultrasound, pregnancy test
What is the treatment and prognosis of ectopic pregnancy?
Surgery- good with prompt treatment
Define spontaneous abortion.
pregnancy loss before 20 weeks
How often do spontaneous abortions occur?
up to 15% of clinically recognized pregnancies, but sensitive gonadotropin assays show that 22% more of pregnancies abort spontaneously, most in first trimester
How does rate of spontaneous abortion occur with aging?
Rate increases from
11% in pregnancies of 20-24 year-olds
to 51% in 40-44 year-olds
What is the most common cause of pregnancy loss in first trimester?
Genetic: half with chromosomal abnormalities
What is the most common cause of pregnancy loss in second trimester?
infectious: acute chorioamnionitis
What is the most common cause of pregnancy loss in third trimester?
Vascular- uteroplacental insufficiency, commonly associated with pre-eclampsia
6 causes of recurrent spontaneous abortion?
Immunologic (especially APLS) 25%, Anatomic 22%;Endocrinologic 20%;Microbiologic 6%; Genetic 3%;Unknown 40%
Recurrent stillbirth is associated with ______ states.
Hypercoagulable
____ is implantation in lower
uterus or cervix, sometimes covering
internal cervical os
Placenta previa
What does placenta previa result in?
severe bleeding, may result in placental rupture, massive bleeding and maternal death
How do you treat and diagnose placenta previa?
ultrasound; c-section
What is placenta accreta?
defective decidua, with adherence of villous tissue to myometrium
What is placenta increta?
defective decidua, with penetration of villous tissue into myometrium
What is placenta percreta?
defective decidua, with penetration of villous tissue through entire uterine wall
Which is more common and least common - p accreta, increta, percreta? What can they cause and how are they treated?
80%;15%;5%
Persistent postpartum bleeding, hysterectomy, or resection or oversewing
What is a hydatidiform mole?
Abnormal gestations due to two sperm
fertilizing one egg, or one or two sperm
fertilizing an “empty egg” with absent
or nonfunctional DNA
How common are hydatidiform moles?
Rare in US (1 in 1,000 pregnancies) Less rare in east [esp. southeast] Asia (1 in 100 pregnancies in Indonesia) Tend to occur in women <20 years old or over 40 years old
Complete moles are _____. Partial moles are ____.
diploid; triploid
Morphology of hydatidiform moles
cystic swelling of chorionic villia makes them resemble grapes. Trophoblast hyperplasia more prominent in complete moles- usually all the way around villi.
How and When are hydatidiform moles diagnosed? How are they treated?
Diagnosed at average of 8.5 weeks due to abnormal ultrasound showing diffuse villous enlargement and/or abnormally rapid and high elevation of beta human chorionic gonado- tropin (beta-HCG) Treated with curretage (scaping out the uterine contents) and monitoring beta-HCG to make sure it is all out
What are the 4 different types of twin placentas?
Dichronic diamnionic (two separate everything) Dichronic diamnionic fused (shared placenta) Monochorionic diamnionic (shared chorion and placenta) Monochorionic monoamnionic (shared placenta, amnion, chorion)
69% of twins are _____. 80% of these placentas are _____.
dichronic diamnionic; dizygotic
30% of twins are _____. All twins with this placenta are _____.
Monochorionic diamnionic. monozygotic
What is twin-twin transfusion syndrome?
unbalanced vascular anastomoses in monochorionic placentas can cause one
twin to get too much blood and the other too little (mono mono)
In twin-twin fusion syndrome, what can death of deprived donor twin cause?
necrotic procoagulant material into the
anastomoses threatening the life of the
other twin and then the mother.
What are the hematogenous placental infections?
T for Toxoplasma gondii O for Other (syphilis, HIV, etc.) R for Rubella (German measles) C for Cytomegalovirus H for Herpes simplex virus
What placental infection ascends from vagina?
acute chorioamnionitis
Where does T. gondii come from and what does it cause?
protozoan from cat feces, causes
microcephaly, fever, rash, seizures
in neonates
What can rubella cause?
causes deafness, neurologic defects,
cardiac malformations, etc. in neonates
Describe cytomegalovirus infection of placenta.
most common transplacental infection
in US, causes deafness, neurologic
defects in neonates
Describe transplacental herpes infection
actually gotten intrapartum from maternal genital lesions, causes skin infection & worse
in neonates, preventable with C section
How common is acute chorioamnionitis?
Common: 41% of women with premature
rupture of membranes at <27 weeks and
15% at 28-36 weeks
What are stages of acute chorioamnionitis? Describe the inflammation
maternal polys in intervillous space, then in chorion, then in amnion, then fetal polys in chorionic blood vessels (fetal vasculitis) where inflammation may lead to thrombosis because Inflammation is procoagulant
What is funisitis?
exudate and congestion of cord
What can be histologically with acute chorioamnionitis?
Polys infiltrating the chorion. Subchronic fibrin with entrapped villi.
What happens histologically in acute chorioamionitis when infection has eaten through the basement membrane of the amnion?
A plug of granulation repair tissue is visible
T or F. Acute chorioamnionitis can be complicated by fetal vasculitis, and thrombosis that can result in fetal demis if occluding the umbilical cord vessels.
T
Histologically, what is seen with intra-amniotic infections?
Sloughing of the amniotic epithelium, thrombi
Describe acute chorioamnionitis. (origin, type, inflammation)
Infection ascends from vagina and cervix Inflammatory response = mainly maternal neutrophils (so starts in intervillous space) Infection is usually polymicrobial, with multiple vaginal flora bacteria
What is acute chorioamnionitis syndrome?
fever, tachycardia (fetal and
maternal), uterine tenderness, foul
smelling amniotic fluid and leukocytosis
Diagnosis, treatment, and prognosis of acute chorioamnionitis
Diagnosis: clinical
Treatment: antibiotics and delivery
Prognosis: usually good, but can cause
fetal sepsis, cerebral palsy, endometritis
What comlications can arise from acute chorioamnionitis?
Causes premature rupture of membranes
(acronym “PROM” [not a dance]) and
premature labor and delivery
(due to inflammatory cytokines)
What 5 things should be included in acute abdomen in women of child bearing age
Ruptured Ectopic Pregnancy
Ovarian Torsion
Appendicitis
Volvulus
Diverticulitis
5 most common causes acute abdomen surgical emergency
- ruptured ectopic pregnancy
- corpus luteum rupture & hemorrhage
- pelvic inflammatory disease
- appendicitis
- ovarian torsion
What causes ovarian torsion?
Twisting on ligamentous support, cutting off
venous outflow and then arterial inflow,
causing ischemia and then infarction
When is ovarian torsion most common?
Most common in women of childbearing age
with ovarian mass or pregnancy (more likely
in first trimester
How does ovarian torsion present? treatment?
Present with acute onset of moderate-severe
pelvic pain, often with nausea and vomiting
Treatment: surgery
What is appendicitis?
Inflammation of appendix due to overgrowth of
normal flora trapped by occluding fecalith
How common is appendicitis with pregnancy?
Occurs in up to 1 in 800 pregnancies (more
likely in second trimester
How does appendicitis present?
Present with periumbilical abdominal pain that
migrates to right lower quadrant, anorexia,
nausea, vomiting, followed by fever, with
tenderness at McBurney’s point halfway
between umbilicus and anterior superior
iliac spine, rebound tenderness if perforated
What is volvulus
Twisting of colonic segment on its mesentery
causing obstruction, dilatation, ischemia
Epidemiology of volvulus
90% sigmoid in elderly men, but cecal volvulus
is most common in patients between 25 & 35
How does volvulus present and what is the treatment?
Present with intermittent cramping lower
abdominal pain, progressive abdominal
distension, passing no stool or flatus, with
marked abdominal distension and tympany
Treatment: untwisting by inserting tube
What is diverticulitis? When is it common? How does it present? What is the treatment?
Inflammation of a transmural outpouching of
colonic mucosa due to perforation +/- abscess
Common, primarily in elderly patients
Present with abdominal pain, often for more
than a day, (left lower quadrant in 70% of whites, right side in 75% of Asians), constipation (50%), nausea + vomiting (?50%), diarrhea (30%), with abdominal tenderness and leukocytosis
Treatment: surgery or non-surgical therapy
Pregnancy causes leukocytosis up to ____ and labor causes leukocytosis up to _____ but neither causes bandemia.
14,000; 30,000
