Ob shit Flashcards
1
Q
What is the definition of placenta?
A
- temporary organ that connects mother and fetus and provides respiratory and renal functions.
- Composed of chorionic villi sprouting from chorion, villi increases SA for blood exchange
2
Q
What are the 5 components of a placenta?
A
- Amnion - membranous sac, surrounds fetus, contains serous fluid
- Chorion - plate shaped, has villous projections w/ fetal blood vessels into villous space w/ maternal spiral arteries
- Decidua - outer layer of placenta attached to myometrium, layered is peeled during placental delivery
- Trophoblast - outermost layer of blastocyst that implants into uterus, forms placenta
- Syncytiotrophoblast - outer covering of chorionic villi, clumped nuclei to decrease diffusion barrier
3
Q
What happens w/ the blood flow in the placenta?
A
- maternal O2-blood enters mature placenta via spiral arteries and ciruclates through villi
- fetal deO2 blood enters placenta via 2 umbilical arteries, branch into chorionic arteries
- Fetal umbilical vein carries O2 maternal blood to baby
4
Q
Is there any mixing of blood that takes place in the placenta?
A
no
5
Q
What is the most common site of an ectopic pregnancy?
A
fallopian tube –> MCC is Fallopian tube scarring.
6
Q
What are other causes of an ectopic pregnancy?
A
- adhesion from appendicitis
- surgery
- endometriosis
* all of these prevent the ovum from reaching the fallopian tube
7
Q
What are the consequences of an ectopic pregnancy?
A
- trophoblasts invade fallopian tube walls but it’s not designed for implantation so no growth/development of the yolk sac can take place –> leads to rupture –> Hemorrhage
8
Q
What happens in pathology of an ectopic pregnancy?
A
hemtaosalpinx (blood filled fallopian tube); belly full of blood (can lead to ileus)
9
Q
How does an ectopic pregnancy present?
A
severe onset of ab pain and pelvic hemorrhage – symptoms usually 6 wks post-normal menstrual cycle
10
Q
What is spontaneous abortion?
A
- Miscarriage - pregnancy loss before 20 wks gestation
- most occur before 12 wks gestation
- increase w/ increasing age
11
Q
What are causes of an miscarriage in the different trimesters?
A
1st trimester - Genetics (chromsomal abnormalities)
2nd trimester - Infectious - Acute chorioamnionitis
3rd trimester - Vascular - uteroplacental insufficiency; Pre-eclampsia
Recurrent SAB (>3) - AntiPhospholipid Syndrome
Recurrent Stillbirth (>20 wks gestation) - Hypercoagulable state
12
Q
What are the 2 different times of Twin Placentas?
A
- Dichorionic Diamnionic
- Monochorionic Diamnionic
- Monochorionic Monoamnionic
* Di-di twins are dizygotic
* mono placentas are monozygotic
13
Q
What is twin-transfusion syndrome in Mono-mono twin placentas?
A
Unbalanced vasculature due to vascular anastomoses leads to abnormal sharing of blood leads to abnormal circulatory volumes –> donor twin dies from decreased blood flow –> releases nectoric material into anastomoses leading to death of twin and even mother
14
Q
What is placenta previa?
A
placenta implants in lower uterus or cervix –> leads to severe bleeding and placental rupture –> hemorrhage/death
15
Q
What is placenta accreta
A
defective decidua –> Severe postpartum bleeding (80%), adherence of villous tissue to myometrium.
16
Q
What is placental increta
A
defective decidua –> Severe postpartum bleeding (15%). penetration of villous tissue to myometrium
17
Q
What is placental percreta
A
defective decidua –> Severe postpartum bleeding (5%). Penetration of villous tissue to entire uterine wall.
18
Q
What is the treatment for a defective decidua
A
hysterectomy > resection
19
Q
What are the causes of a hematogenous placental infection?
A
- Toxoplasma Gondii - protozoan, cat feces
- Others - syphilis, HIV, TB ( rare w/ PNC)
- Rubella
- CMV: most common transplacental infxn in US
- HSV: acquired intrapartum from maternal lesions of active infxn
TORCH!!!
20
Q
What are the clinical presentations for TORCH?
A
- Toxo: microcephaly, seizures, rash/fever in neonates
- Rubella - deafness, neurologic defects, cardiac malformation
- CMV - deafness + neurologic defects
- HSV - skin lesions/infxns in neonates –> prevent w/ C-section
21
Q
What are the consequences of a hematogenous placental infxn?
A
premature rupture and preterm delivery
22
Q
What is the cause of an ascending placental infxn?
A
Acute Chorioamnionitis
23
Q
What is the etiology of acute chorioamnionitis?
A
polymicrobial infxn w/ vaginal flora bacteria ascending up the genital tract.
24
Q
What happens in acute chorioamnionitis?
A
- Maternal polys acess intervillous space –> polys progress to infect fetus via chorionic blood vessels.
- The fetus has an immune response that leads to an inflammatory state ==> pro-coagulable
25
What is the gross pathology of acute chorioamnionitis?
tan exudate w/ congestion and green discoloration of amniotic surface. Funisitis of umbilical cord can occur.
26
What is the microscopic pathology of acute chorioamnionitis?
1. wavefront of polys from chorion to amnion to amniotic fluid
2. Granulation tissue occurs where infxn damaged the BM
3. sloughing of amniotic epithelium and fetal thrombosis
27
What is the clinical presentation of acute chorioamnionitis?
TUFF Luck
1. Tachycardia
2. uterine tenderness
3. foul smelling amniotic fluid
4. fever
5. Leukocytosis
28
What are the complications of acute chorioamnionitis?
fetal sepsis, cerebral plasy, and endometritis
29
What is a cause of acute chorionamnionitis?
premature rupture of membranes and premature labor/delivery (caused by inflammatory cytokines)
30
Who is more commonly to get hydatidiform mole?
southeast asians, women less than 20 or women greater than 40
31
What is a hydatidiform mole?
abnormal fertilization leading to abnormal gestation. Complete vs Partial
32
How does a complete mole form?
1. empty egg + duplication of single sperm
2. empty egg + two sperm
* diploids!
33
how does a partial mole form?
normal egg w/ 2 sperm -- Triploid
34
What is the pathology of hydatidiform moles?
1. Gross: cystic swelling -- grapelike
| 2. Micro: edematous villi; complete mole has trophoblast hyperplasia
35
how do you dx a hydatidiform mole?
ultrasound will show diffuse villous enlargement and increased beta-hCG
36
What is a related disease for a hydatidiform mole?
can become an invasive mole leading to a choriocarcioma. Complete moles more than partial. Invasive moles appear like choriocarcinomas but DON'T metastasize
37
what is a choriocarcinoma? how does it mets?
trophoblastic neoplasms; via blood to lung, liver, brain, spleen, kidney
38
What does a choriocarcinoma look like>
1. fleshy soft yello white tumor --> rapid growth can lead to ischemic necrosis and hemorrhage
2. micro: mixed trophoblasts
39
What is the most common first symptom of a choriocarcinoma?
uterine bleeding
40
What is the prognosis of a choriocarcinoma?>
70% survival w/ hysterectomy/chemo even w/ metastasis
41
What are causes of acute abdomen of pregnancy?
1. ovarian torsion
2. appendicitis
3. volvulus
4. ruptured ectopic pregnancy
5. diverticulitis
42
What is ovarian torsion?
twisting of ovary on ligamentous support leading to obstruction of venous drainage and blood supply = ischemia and eventually infarction
43
When is ovarian torsion most common?
in women of childbearing age w/ ovarian mass or pregnancy (increased mass from corpus luteum in 1st trimester)
44
What does an ovarian torsion present as?
acute onset of pelvic pain, N/V
45
What causes appendicitis?
overgrowth of appendix from normal flora overgrowth trapped by occluding fecalith, associated with a decreased fiber diet
46
When does appendicitis usually present in pregnanacy
2nd trimester. Initial periumbilical pain that becomes RLQ pain. rebound tenderness at McBurney's point
47
Where is the McBurney's point found
1/2 btw umbilicus and ASIS
48
What is volvulus
twisting of colonic segment on its mesentery --> obstruction, dilation, and ischemia --> infarction. Untwisting can release colonic bacteria into blood and cause sepsis.
49
What is the classic presentation of volvulus
intermittent camping lower abdominal pain, gradual abdominal distention/tympani (no stools, flatus)
50
how can you differentiate causes of acute abdomen from pregnancy
Pregnancy will have leukocytosis up to 14,000
Labor will have leukocytosis up to 30,000
But neither have bandemia which is present in acute abdomen
51
what are the causes of acute abdomen in order
1. ruptured ectopic pregnancy
2. corpus luteum rupture/hemorrhage
3. PID
4. appendicitis
5. ovarian torsion
52
what is diverticulitis
inflammation of a transmural outpouching of colonic mucosa due to perforation +/- abscess
53
What is the presentation of diverticulitis
abdominal pain for more than one day.
LLQ pain = whites; RLQ pain = Asians
Leukocytosis, constipation, diarrhea, N/V
Common in old men
54
What is pre-eclampsia
systemic syndrome w/ widespread maternal endothelial dysfunction w/ HTN, EDEMA, and PROTEINURIA
55
What are the risk factors for pre-eclampsia
```
1st pregnancy, multiple pregnancies, increased intervals btw pregnancies
Age <20; .40
Obesity, DM, HTN
New Paternity
previous pre-eclampsia
```
56
What is the pathogenesis of pre-eclampsia
Abnormal placental vasculature. The pre-eclamptic trophoblasts fail to convert spiral arteries (increase their capacitance to accommodate increased blood flow) --> leads to an ISCHEMIC PLACENTA
57
What happens due to an ischemic placenta
1. release of anti-angiogenic factors: sFlt1 and endoglobin --> decreased NO and PGI2 leads to maternal HTN, Edema, and proteinuria
2. Ischemic placenta releases pro-inflammatory cytokines :TNF alpha
58
What does sFlt1 do?
truncated form of VEGA-R that binds up circulating maternal VEGF
59
What does endoglobin do?
TGF-b receptor that binds up circulating maternal TGF-b
60
What kind of state does the inflammation lead to?
PRO-COAGULABLE State leads to endothelial dysfunction and increases TPR and MAP
61
What is the placental pathology for pre-eclampsia?
Atheroscleorsis of placental vessels, Villous Hypoplasia, Fibrin clots in intervillous space (can lead to necrosis),
62
What happens to the fetus in pre-eclampsia
intrauterine growth restriction, hypoxia, and death may occur
63
What happens to the maternal pathology in pre-eclampsia
fibrinoid necrosis of uterine blood vessels and subendothelial macrophages
64
When does one make the dx of pre-eclampsia
new onset of HTN and proteinuria post 20 wks of gestation
65
What are complications of pre-eclampsia
eclampsia
| 10% pts get HELLP
66
What is HELLP
hemolysis, elevated liver enzymes, low platelets
67
What is the pathogenesis of HELLP
platelets and clotting factors are activated --> fibrin clots in capillaries/hepatic sinusoids, destruction of RBCs, platelet aggregation
68
What are complications of HELLP
DIC, hepatorenal syndrome, pulmonary edema/ARDS
69
what is the pathology of HELLP
peripotal zone of hepatic lobule showing fibrin deposition
70
what are the causes of maternal death in order?
1. thromboembolism
2. hemorrhage
3. pre-eclampsia
4. others
71
What are 2 reasons for resulting in placenta ischemia
1. decreased blood supply
| 2. increased flow resistance to placenta
72
How much infarction of the placenta can the fetus tolerate
50%
73
What are consequences of extensive placental infarction
IUGR, neurologic injury, and fetal demise
74
what does and older and a new infarct of the placenta look like
Old- tan
| Subacute- red granulation tissue
75
What are some etiologies of a placental ischemia/infarction
1. pre-eclampsia
2. hypercoagulable state (lupus)
3. AI vasculitis
4. Smoking
76
What is oliohydraminos
deficiency in amniotic fluid -- leads to Potter sequences
77
What is the pathogenesis of oligohydramnios
1. decreased amniotic fluid by renal agenesis leads to decreased urine production which is the main component of amniotic fluid
78
What are the consequences of oligohydraminos
fetal compression and pulmonary hypoplasia, nose and ears are especially flattened, contracture of hands/feet
79
What is an amniotic band
mechanical fibrotic lesions causing limb structures, may result in amputations
80
what are umbilical knots
- can cause fetal demise especially in 2nd trimester w/ increased fetal pulling/movement
- true knots - cord tied up
False knots - hyper/hypocoiling (associated w/ poor obstretical outcomes)
81
What is placental abruption
bleeding at decidual-placenta interface causing partial of total placental detachment before delivery -- forms a retroplacental hemorrhage (1/3 can occur w/out abruption)
82
What is the pathogenesis of an amniotic fluid embolism
fetal/amniotic elements enter maternal veins as decidue detaches and can embolize to lungs causing vasospasms, HTN, and RH failure
83
What is seen on pathology for an amniotic fluid embolism
small calcifications from placenta, elongated flattened light/purplish strucutres - squamoid/squamous cells from amnion
84
What are consequences of an amniotic fluid emboli
DAD, DIC, hemorrhage
85
What is peripartum cardiomyopathy
myocarditis resolving spontaneously(1/3) or leads to dilated cardiomyopathy (2/3) -- usually 3 months before or after delivery
86
Who is more likely to get a peripartum cardiomyopathy
multiparous AA
