208/209/210 - Normal and Abnormal Pregnancy, Anatomy and Pathology of Implantation Flashcards
1
Q
How will the following change during pregnancy?
- D-Dimer:
- Alk phos:
- Albumin:
A
- D-Dimer: increase
- Does not indicate VTE - but pregnancy is a hypercoagulable state, so make sure not to miss?
- Alk phos: increase
- Albumin: decrease
2
Q
In general, at what gestational age is it better to perform a preterm delivery than to manage expectantly?
(In situations like preeclampsia, PROM, etc)
A
34 weeks
Before 34 weeks, try to manage expectantly - usually delivery will occur within 1 week, but give a chance to administer antenatal steroids, give the baby a few extra days to grow
3
Q
What defines fetal growth restriction?
Why is it important to diagnose?
A
Fetal growth below the 10th percentile
- Counsel pts on prognosis, options
- Start antenatal surveillance
- Administer antenatal steroids if preterm birth is looking likely
4
Q
What defines preeclampsia?
A
New onset HTN + proteinuria
Defined as severe if ANY of the following are present, even w/o proteinuria
- BP > 160/110 on 2 occasions, at least 4 hours apart
- Maternal symptoms (headache, visual changes, RUQ pain)
- Hepatic injury
- Renal dysfunction
- Pulmonary edema
- Coagulopathy
- HELLP syndrome
- Eclampsia
5
Q
How will the following change during pregnancy?
- GFR:
- Serum CR:
- Ureter position:
- Kidney size:
A
- GFR: increase
- Serum CR: decrease
- Ureter position: displacement, R>L
- Kidney size: increase slightly
6
Q
List 3 important steps in the management of preterm labor
A
- Give mom steroids -> accelerates fetal lung development
- Give mom penicillin: GBS prophylaxis
- Empirically, even if screening test has not been completed yet
- Give mom magnesium: fetal neuroprotection
- Reduces cerebral palsy risk
7
Q
Describe the management of preeclampsia
A
Definitive treatment is delivery
If not severe and <34 weeks, may attempt expectant management
- Control BP
- MgSO4 to prevent seizure
- Give antenatal steroids
8
Q
How is isoimmunization managed?
A
The pregnancy at risk is the second pregnancy, after Rh(-) mother develops antibodies to Rh during first pregnancy
(If mother was not given Rh immmunoglobulin during first pregnancy)
- Look at serial antibody titers
- 1:32 and above (so 1:16 and 1:8), fetus is at risk of anemia
- Transfer adult RBCs to fetus to prolong gestation
9
Q
What is the difference between spontaneous abortion and stillbirth?
A
Gestational age
- Sponataneous abortion
- Pregnancy loss < 20 weeks gestation
- Stillbirth (aka intrauterine fetal demise)
- Pregnancy loss ≥ 20 weeks gestation
- Less common than spontanteous abortion
10
Q
List the causes of fetal vascular malperfusion (4)
A
- Umbilical cord abnormalities:
- Twisting
- Velamentous insertion
- Mechanical obstruction
- Thrombus formation
11
Q
What physiologic difference will be present in the chest x-ray of a pregnant person?
A
Enlarged cardiac silouette due to elevation of the diaphragm
Heart will look too big, but it’s fine
12
Q
How do estrogen and prgesterone affect the uterus during pregnancy?
A
Estrogen -> Uterine hypertrophy
Progesterone -> Relaxation of uterine walls so fetus can grow
13
Q
Which umbilical vessels deliver oxygenated blood to the fetus?
A
Umbilical vein
Umbilical arteries deliver deoxygenated blood from fetus to placenta
14
Q
How will the following change during pregnancy?
- HR:
- CO:
- BV:
- SV:
- BP:
A
- HR: increase
- CO: increase
- BV: increase
- SV: increase
- SVR: decrease
- BP:
- 1st trimester: normal
- 2nd trimester: may dip a bit 2/2 decreased SVR
- 3rd trimester: back to normal
15
Q
At what gestational age does the fetus begin to synthesize its own thyroid hormone?
A
10 weeks
Relies on maternal TH until then
16
Q
How will the following change during pregnancy?
- Clotting factors:
- tPA:
- Protein S:
- Activated protein C:
A
- Clotting factors: increase
- tPA: increase
- Protein S: decrease
- Activated protein C: decrease
Also, RBCs and plasma volume both increase, but plasma volume increases more -> physiologic anemia
17
Q
Onset of labor before what gestational age counts as preterm?
A
<37 weeks
37 weeks + 0 days = term
18
Q
Does the umbillicl cord contain maternal blood or fetal blood?
List the vessels in the cord
A
Fetal blood only
- 1 umbilical vein carries oxygenated blood from placenta to fetus
- 2 umbillical arteries carry deoxygenated blood from fetus to placenta
19
Q
What is the most common cause of spontaneous abortion?
A
Chromosomal abnormalities
20
Q
Describe the management of placenta previa
A
- Pelvic rest
- Manage expectantly if <37 weeks
- Planned C-section at 37 seeks
- Labor is a risk factor for maternal hemorrhage
21
Q
What is happening during stage 1 of labor?
A
Onset of labor -> full cervical dilation
- Latent phase happens slowly
- Active phase = acceleration
- Usually at 4-6 cm
- Usually happens more quickly in people who have delivered a baby before
22
Q
List the stages of labor and what is happening at each stage
A
- Stage 1
- Onset of labor -> full cervical dilation
- Stage 2
- Full cervical dilation -> delivery of fetus
- Stage 3
- Delivery of neonate -> delivery of placenta
23
Q
Describe the pathophsyiology of isoimmunization
A
Rh (-) mother is exposed to Rh (+) fetal blood
- -> Maternal production of antibodies
- -> Next pregnancy = antibodies attack fetal RBCs
- Prevent by administering Rh immune globulin to all pregnant women who are Rh (-) at 28 weeks, after delivery, and any time there is concern for breakage of the feto-maternal barrier*
- Manage by transfering adult RBCs to fetus to prolong gestation if fetal anemia is developing*
24
Q
Which two classes of drugs can be given to stop labor?
A
- Beta-2 agonists (terbutaline)
- Maintain relaxation of the myometrium
- Calcium channel blockers (nifedipine)
- Prevent depolarization of myometrial cells
25
The corpus luteum supports pregnancy until __ weeks gestation
The corpus luteum supports pregnancy until **_7_** weeks gestation
26
How will the following change during pregnancy?
* Minute ventilation:
* Residual volume:
* Tidal volume:
* Functional residual capacity:
* Acid/base balance:
* Minute ventilation: **Increase**
* Tidal volume: **Increase**
* Residual volume: **Decrease**
* Functional residual capacity: **Decrease**
* Acid/base balance: **Respiratory alkylosis**
* Due to decrease in maternal pCO2, compensated by excretion of bicarbonate
Residuals decrease
Everything else (including pH) increase
**Most changes are compensatory 2/2 elevated diaphragm**
27
What is an "abnormally adherent placenta"?
What are the 3 different types?
The placenta implants into a layer of the uterus that is **deeper than the decidua**
* **Accreta** = implantation on the myometrium
* **Increta** = invasion into the myometrium
* **Percreta** = invation through uterine serosa into adjacent structures
28
What protective structure is lost if a fetus has velamentous umbilical vessels?
Wharton's jelly
* Supposed to surround the umbilical vessels
* If cords insert directly into the membrane (instead of the disk), they are at risk for rupture
29
Which situation is more urgent:
1. Bleeding from placenta previa
2. Bleeding from vasa previa
How do you tell them apart on presentation?
b. Bleeding from vasa previa
More dangerous because ***fetal*** blood - fetus can bleed out very quickly - do an emergency c-section!! (within seconds-minutes)
Vasa previa will have **worrisome fetal monitoring**; placenta previa will have reassuring fetal monitoring
Also, Apt test: fetal hemoglobin is resistant to lysis by alkaline solutions (but realistically, you don't have time to do this test)
30
How is cervical insufficiency managed?
Cerclage
* If CI is happening =\> emergent cerclage
* *Contraindications: contractions (implies labor), fetal demise, infection*
* If risk factors but has not happened yet =\> prophylactic cerclage
*Cerclage = suture that gives structural integrity/closure of cervix*
31
What microscopic findings may be present in vaginal secretions in PROM?
"ferning" pattern
* Caused by salt in the amniotic fluid
32
Which tumor of gestational trophoblastic tissue is large and hemorrhagic?
Choriocarcinoma
*Less hemorrhage in partial and complete moles*
33
What are the serious consequences of fetal vascular malperfusion?
* Cerebral palsy
* Intrauterine or neonatal fetal demise
34
List the 3 membrandes of the placenta, from fetus to uterus
* Amnion
* Chorion
* Parietal decidua (maternal layer)
* Endometrium that is modified to support pregnancy
*They are in alphabetical order*
35
List 3 tumor types that can arise from gestational trophoblastic tissue
* Complete hydatidiform mole (no maternal DNA; 46XX or 46XY)
* Partial hydatidiform mole (maternal DNA; 69XXX of 69XXY)
* Choriocarcinoma
* Pure trophoblastic proliferation; no chroionic vili
* Large, hemorrhagic
36
List 2 problems that can occur due to interwtin vascular conditions
* Twin-to-twin transfusion syndrome
* Donor twin is anemic
* Recipient twin i splethoric
* Twin reversed arterial perfusion
* Pump twin -\> hydrops
* Can have relatively normal gestation if acardic twin is removed
* Other twin is acardic
## Footnote
*May occur in monochorionic twin placentas*
37
How will blood sugar change during pregnancy?
Mild fasting hypoglycemia (increased insulin)
Mild post-prandial hyperglycemia (insulin resistance)
38
If a twin pregnancy is diamniotic, what can you say about whether the twins are monozygous or dizygous?
May be either
* Dizygous twins are ALWAYS diamniotic
* Monozygous twins may be diamniotic or monoamniotic
39
Describe the pathogenesis of preeclampsia
Failure of spiral artery to transform into a high-capacitance vessel
* -\> Cannot perfuse chorionic villi
* -\> Hypoperfusion
* -\> Placental ischemia
* -\> **Immune reaction involving cytokines**
* **-\> Hypertension**
40
How does the cervix change during pregnancy?
Chadwick sign present
Due to hypertrophy and hyperplasia of cervical glands, eversion of proliferating **columnar** endocervical glands
41
What is cervical insufficiency, in the context of preterm labor?
Painless cervical dilation with the **absence** of uterine contractions
* Usually 16-24 weeks
* May be related to collagen abnormalities (ex: Ehler's Danlos)
*If uterine contractions + cervical dilation = preterm labor; CI is NOT preterm labor*
42
What triggers labor?
(How do the mother and fetus know when it's time?)
The **placental clock** determines the timing of labor
* **Cortisol releasing hormone** produced by the **placenta**
* **-\> Maternal cortisol production**
* -\> Placental estrogen production
* -\> Myometrial contractility
* **-\> Fetal adrenal and pituitary activity**
* -\> Lung maturation, surfactant production
* -\> Myometrial contractility
43
Where in the fetus/placenta will we see inflammation in an ascending (vaginal) vs. hematogenous infection?
* Ascending:
* Maternal neutrophils in maternal arteries, move to amniotic fluid
* -\> Fetal neutrophils in the **umbillical cord and on the chroionic plate**
* Hematogenous
* Fetal inflammation in **villi and intervillous space**
* Either **Chronic (lymphocytes) or acute (neutrophils) villitis**
44
If a twin pregnancy is monochorionic, are the twins monozygotic or dizygotic?
Monozygotic
45
Where does amniotic fluid come from...
* \<16 weeks:
* \>16 weeks:
* \<16 weeks: **diffusion from maternal circulation**
* \>16 weeks: **fetal urine**
46
During gestation, where is the fetoplacental interface?
What are the boundaries of the fetal and maternal portions, respectively?
Chorionic villous = fetoplacental intervace
* **Fetal side:** Chorionic villi
* Cytotrophoblasts + syncytiotrophoblast
* As the barrier thins later in pregnancy, syncytiotrophoblasts only
* **Maternal side:**
* Extravillous trophoblasts
* Remodeled vessels
* Basal plate
*Basically, the villi/villous trees are fetal - the trophoblasts are maternal. They touch to exchange gas, nutrients, but blood does not mix!*
47
What is the etiology of **fibrinoid necrosis** in placental vessels?
**Maternal** vascular malperfusion
* Caused by maternal HTN or preeclampsia
* Results from failure of trophoblasts to remodel maternal vessels into high-capacitance (high-flow vessels)
* -\> chronic hypoxia
* -\> **fibrinoid necrosis**
48
What is considered "normal pregnancy weight gain"?
25-35 lbs, if normal pre-pregnancy weight
* Equates to ~300 extra calories/day*
* But tbh if I'm every growing a baby inside of me I will eat as much as I please*
49
List the 3 shunts in fetal circualtion and what they bypass
* **Ductus venosus**
* Portal vein -\> IVC
* Bypasses liver
* **Foramen ovale**
* Right atrium -\> left atrium
* Bypasses RV, lungs
* **Ductus arteriosus**
* Pulmonary artery -\> aorta
* Bypasses fetal lungs, LA, LV
50
Describe the difference in presentation:
Placental abruption vs. placenta previa
* **Placental abruption**
* Vaginal bleeding **+ uterine contractions/pain**
* Caused by placenta separating from wall of uterus
* **Placenta previa**
* **Painless** vaginal bleeding
* Caused by placenta covering cervical os
* Placental abruption is a little bit more urgent - manage expectantly if mom and fetus are doing well, deliver if either is looking distressed*
* Placenta previa = initiate pelvic rest, plan a c-section at 37 weeks*
51
How can isoimmunization be prevented?
Administer **Rh immune globulin** to all pregnant women who are Rh (-) at **28 weeks**, **after delivery**, and any time there is **concern for breakage of the feto-maternal barrier**
* This prevents mom from developing atigens against Rh:*
* The anti-Rh IgG neutralizes Rh-expressing fetal RBCs in maternal circulation before the maternal immune system can detect and become sensitized to fetal RBCs*
* Thank you @Ben Gastevich!*
