Practice Questions - Large Doc 3 (125-396) Flashcards
1
Q
Fetal O2 dissociation curve:
- ____ shift
- What causes increased O2 affinity?
A
L shift - higher fetal hgb, increased O2 carrying capacity (higher O2 sat for lower PaO2)
Increased O2 affinity - decrease of 2,3 DPG binding to fetal hgb
- 2,3 DPG and acidosis shift curve to R (release O2 to tissues)
2
Q
Most common cause of fetal bradycardia:
A
Complete heart block (50% have structural defect) or major structural anomaly (AV canal)
Other causes:
- BB
- Fetal panhypopituitarism
- Fetal brain stem injury
- Isoimmunization
- Postcervical block - occurs 7min later and lasts 8min
3
Q
Fetal testosterone importance
A
Max at same time as max hCG
hCG from syncytiotrophoblasts acts as LH surrogate to stimulate replication of Leydig cells and T synthesis 🡪 male sex differentiation
- T acts on Wolffian ducts -> vas deferens, epidydimis, seminal vesicles
- In external genitalia, converted to 5-alpha DHT for virilization
4
Q
Causes of severe thrombocytopenia in newborn
A
Prematurity - RDS, placental insufficiency, sepsis
Term - NAIT, ITP
Can also be caused by SLE
5
Q
Gestational thrombocytopenia
A
Increased platelet destruction that occurs in normal pregnancy
Most common cause of TCP in pregnancy
- Need to rule out PEC and other causes (ANA, APAS< HIV)
6
Q
PKU
- Inheritance?
- Enzyme affected?
- Clinical sequelae?
- How to reduce risk?
A
Autosomal recessive
Absence of phenylalanine hydroxylase
- Can’t metabolize to tyrosine
Excess phe -> neuro damage, MR, hypopigmentation, microcephaly, CHD
Maintain maternal levels 2-6
Phe crosses placenta by active transport
7
Q
Factors considered w/ AFP
A
Maternal weight (decreases w/ increased weight)
Smoking (increases)
# fetuses
GA
Diabetes
Maternal age
8
Q
Where is GnRH synthesized? What does it do in the placenta?
A
Hypothalamus
Placenta - cytotrophoblasts
- Stimulates hCG
- Peaks at 8wks
9
Q
Where is hCG made?
A
Syncytiotrophoblasts
10
Q
Which coags increase and decrease in pregnancy?
A
Increase - I, VII, VIII, IX, X
Decrease - XI, XIII
Same - II, V, XII
11
Q
Monozygotic twins rate
A
0.4% of births
12
Q
Local anesthesia toxicity
A
CNS and CV components
Excitation, tinnitus, disorientation -> seizure
Tachycardia and HTN -> hypotension, arrhythmia, cardiac arrest
13
Q
Which local anesthetic is more cardiotoxic?
A
Bupivicaine - longer half life
14
Q
Treatment of SVT
A
Vagal
Then - digoxin, adenosine, CCB
Fetal bradycardia can result from meds
15
Q
ASA side effects
A
Decreased ctx (prostaglandin inh) -> delayed labor
Plt dysfunction in neonate w/in 5 days of taking
Closure of fetal DA
16
Q
ACEi effects on fetus
A
Late-onset IUGR, oligo
Neonatal hypotension, anuria
Most severe - renal tubular dysgenesis - early oligo, pulm hypoplasia, contractures, hypocalvaria
17
Q
Contraindication to prostaglandin F2 alpha
A
Asthma
Also known as carboprost (hemabate)
18
Q
Turner syndrome - etiology
A
Postzygotic mitotic error
Age unrelated
Maternal X retained 80%
19
Q
Most common intracranial finding of NTD
A
Decreased cisterna magna
20
Q
Most common fetal sustained tachyarrhythmia
A
SVT
Then atrial flutter, then afib
21
Q
Fluids in DKA
A
NS until glucose <250, then D5NS
22
Q
Myometrial contractility
A
Actin/myosin -> myosin light chain kinase -> contraction
Increased intracellular calcium -> activated MLCK -> contraction
23
Q
Fetal risk with chlamydia
A
Conjunctivitis (50%)
Pneumonia (3-18%)
24
Q
Pregnancy prognosis in RA
A
1st tri - 74% remission
2nd tri - 20%
3rd tri - 5%
90% PP flare (most likely to improve)
25
Pregnancy prognosis in CHTN
Temporary fall in BP, rises in 3rd trimester somewhat higher than early pregnancy
26
Pregnancy prognosis in SLE
Rule of 1/3
27
Pregnancy prognosis in SS
Complications more common, more likely to worsen
28
Fetal hydantoin syndrome
IUGR, MR, craniofacial (cleft, wide mouth, thin upper lip), hypoplasia of distal phalange/nails, wide-spaced nipples
29
Risk of NTD w/ valproate
1%
Also 1% with carbamazepine
30
Warfarin embryopathy
5% risk, 6-12wks GA
Nasal hypoplasia, bone stippling, ophtho (optic atrophy), MR
31
Fetal alcohol syndrome
IUGR
Facial (small palpebral fissures, small/absent philtrum, epicanthal folds, flattened nasal bridge, low set ears, midface hypoplasia)
CNS (MR, ADD)
32
Isotretinoin sequelae
Microtia/anotia
Micrognathia
Cleft palate
CHD
Thymus
Retinal/optic nerve abnormalities
CNS malformations including hydrocephalus
33
Diseases caused by mitochondrial inheritance
MERRF
LHON
Leigh
Pigmentary retinopathy
34
Most common karyotype in partial mole
Triploid
69 XXY (70%)
2 paternal, 1 maternal
35
Findings in 45 XO
Lymph collections
CHD (L sided - coarc)
Renal (agenesis, horseshoe/pelvic kidney)
36
T21 findings
60% thickened NF/NT
10% cystic hygroma
50% CHD
2% duodenal atresia
2% omphalocele
5% pyelectasis
37
Most common causes of hydrocephalus
Aqueductal stenosis (43%)
Dandy-Walker (12%)
Communicating (38%, often idiopathic)
Most common genetic cause - X-linked hydrocephalus
38
Association w/:
CPC
Holoprosencephaly
Clenched hands
CPC - T18
Holoprosencephaly - T13
Clenched hands - T18
39
Anencephaly causes urinary estradiol to:
Decrease - absent fetal zone of adrenal cortex (no HPA means no ACTH stim of fetal adrenals)
40
Toxo diagnosis
Active infection - rise in IgG x 2
- Very high titers >1:512 indicate more recent infection
PCR - allows prenatal dx in a day
41
Histopathology - chorioamnionitis
Mononuclear and PMNs in chorion
42
Histopathology - Syphilis
Large, pale placenta. Villi lose arborization and are thicker, club shaped.
43
Histopathology - Erythroblastosis fetalis
Large placenta. Villous stromal edema. Increased fetal RBCs in vessels.
No trophoblast proliferation (unlike mole)
44
Histopathology - Mole
Villi mass of vesicles. Hydrops, villous stromal edema, absence of blood vessels in edematous villa, proliferation of trophoblastic epithelium, absence of fetus/amnion
45
Abruption causing IUFD w/ consumptive coagulopathy - next steps
If severe enough to kill fetus, stabilize mom and induce
Moderate bleeding, uterus tetanic and painful w/ grade 3 abruption
Low hgb/hct, fibrinogen, platelets
High fibrin degradation products
46
Who has the lowest glucose?
- Non-pregnant
- Pregnant
- Newborn
Term fetus or newborn (15 lower than mom in 3T)
Then pregnant (68)
Then non-pregnant (79)
47
Who has the lowest Hgb/Hct?
- Non-pregnant
- Pregnant
- Newborn
Pregnant - hgb 11
Non-pregnant - hgb 13
Fetal - hgb 17
Hct - fetus 43.5 at term, neonate 51-59
48
Who has the lowest calcium?
- Pregnant mom
- Fetus
Maternal - 9.2
Fetal - 10.4
49
Who has the lowest iron?
- Non-pregnant
- Pregnant mom
- Fetus
Non-pregnant - 90
Maternal - 56
Fetal - highest >100
50
Incidence of chromosomal abnormalities in 1st trimester SAB?
50-60%
Most commonly autosomal trisomy
51
Incidence of chromosomal abnormalities in IUFD?
5%
52
Incidence of chromosomal abnormalities in screened neonates?
Major congenital anomaly - 3%
0.18% by age 25
53
Reasons for elevated AFP other than NTD?
Underestimate GA
Multiples
IUFD
Isoimmunization
Cystic hygroma
Other causes of fetal edema/skin defects
- Omphalocele, gastroschisis
54
Basis of KB test
HgbF resistant to acid (remains intact) and uptake of stain - are pink, maternal cells "ghost-like"
55
KB calculation for Rhogam
Volume of fetal blood = % fetal cells x 50
Need 1 vial (300mcg) for every 30ml fetal blood
56
High spinal - location, management
T4
Numbness/weakness in fingers/hands means C6-8 involved (close to diaphragm)
If breathing and ok CV status, reassurance and O2
If diaphragm involved, need assisted ventilation
CV support as needed
Displace uterus lateral
57
Normal cord gases
Venous - pH 7.32-7.35; pCO2 38.2-43.8, HCO3 20.4-22.6, BE -2.4-2.9
Arterial - pH 7.24-7.28, pCO2 49.2-56.3, hCO3 22-24.1, BE -2.7-3.6
58
Cord gas in metabolic acidosis
Normal pCO2, decreased HCO3
59
Cord gas in respiratory acidosis
Increased pCO2, normal HCO3
60
Fetal effects of maternal hyperventilation
Maternal resp alkalosis, decreased pCO2
Severe anxiety, ASA toxicity, fever, sepsis, PNA/PE, high altitudes
Increased FHR?
Shift in O2 dissociation curve? Lower pO2 in umbilical cord and lower uterine blood flow, but alkalosis causes L shift and higher affinity of hgb for O2. This plus increased umbilical blood flow compensates to allow O2 delivery to fetus to remain constant
61
Fetal effects of maternal hypoventilation
Increased pCO2 -> respiratory acidosis in baby
62
Scalp pH interpretation
pH is same as capillary blood - lower than umbilical venous pH, similar to arterial
Cutoff <7.2 is abnormal
Metabolic acidosis occurs when fetus receives inadequate O2 to maintain normal metabolism and has to switch to anaerobic metabolism
63
What happens to maternal cholesterol in pregnancy?
Increases
Lipids increase - total, free, and triglycerides
Due to estrogen, progesterone, hPL
- HDL peaks at 25wks
64
Lipid profile in diabetics?
Increased TG, decreased HDL
TG and VLDL correlate w/ estriol and insulin
65
Breakdown of zygosity in twinning
Dizygotic = 80% (variable in diff populations)
Monozygotic = 20% (0.3% of all births)
- 13-14% mo/di (75% of monozygotic twins)
- 6-7% di/di (25% of monozygotic twins)
- 1% mo/mo
66
Listeria
Transplacental transmission - Microabscess, chorio (granulomatosis infantiseptica)
50% mortality
- Worse prognosis w/ prematurity
- 100% loss in 1T, 70% in 2T, <5% in 3T
Early onset sepsis (infxn in 1st week of life - acquired during or after birth)
Can also have late-onset - more variable
Can manifest as meningitis - usually after 3 days of age
67
Coxsackievirus
Hepatitis, myocarditis, encephalitis
Chorio
68
Varicella
Congenital varicella syndrome:
In 1st half of pregnancy - can cause malformations
- Chorioretinitis, cerebral cortical atrophy, hydronephrosis, skin/body leg defects
- Highest risk 13-20wks
Neonatal VZV infection:
Exposure before or during delivery means no maternal antibody protection
- Can lead to disseminated visceral and CNS disease -> death
VZIG should be given if maternal infection within 5 days of delivery
69
How long after MMR should you wait to conceive?
3 months
70
What CV issues are beta blockers used in?
Marfan's - aortic root diameter >4cm
Mitral stenosis - BB to reduce HR, allow diastolic flow across valve, improve pulm congestion; most also need lasix
Septal defects - BB for HR control
- W/ significant pulm/systemic shunt, can normally expand CO but with high pulm flow, may get tachyarrythmias
IHSS - BB if pt has angina, dizziness, exertional dyspnea to reduce contractility and HR
71
Placental sulfatase deficiency
= X-linked ichthyosis (X-linked recessive)
Causes low estrogen, long pregnancies, difficult to get into labor
72
Recurrence risk of pyloric stenosis
Doesn't follow classic Mendelian inheritance, but is likely hereditary
- Multifactorial threshold model - caused by polygenic inheritance of genes that are modified by sex and environmental factors
- Model assumes that the “liability” to pyloric stenosis is determined by the additive effect of numerous genetic and environmental factors and that the condition is expressed when an individual's liability exceeds a critical threshold value = all or none
More common in males
If affected female, siblings/children have even higher chance of being affected - recurrence 2-3% higher than avg
- Male siblings/offspring at greatest risk
73
What conditions that cause mental retardation are correctable in infancy?
Maple syrup urine disease
- AR, due to deficiency of branched chain ketoacid dehydrogenase
- Increased levels of branched-chain amino acids leucine, isoleucine, and valine
- Dietary restriction to reduce toxic metabolites - BCAAs
PKU
- AR
- Early dx to prevent neurologic disease - treatable
Congenital hypothyroidism
- Most commonly due to thyroid agenesis
- Most sequelae preventable - early and aggressive thyroxine replacement
74
Most common cause of intellectual disability?
Genetic abnormalities
- Chromosomal abnormalities - Down syndrome single most common known genetic cause of ID
Prenatal causes - 73%
75
What percent of children w/ 5min Apgar <5 will have ID?
5%
Associated w/ 25% cases of CP
76
Definition of perinatal asphyxia
pH <7, BE >11, Apgar <3 at 5min
Evidence of neuro sequelae like seizure, hypotonia, etc; organ system dysfunction
Unlikely to have ID in absence of seizure or CP (isolated cognitive deficits unlikely)
77
Robertsonian translocation - risk of abnormal child
15% if carried by mom, 2% if by dad
5% of RPL
78
Estriol in pregnancy
- Precursor?
- When is it detected and when does it surge?
- What can abnormal estriol signify?
Precursor - DHEAS (fetal adrenals)
Detected at 9wks, surges at 35-40wks
Abnormal could signify - fetal compromise (drops quickly after fetal death), anomalies (T21, anencephaly, adrenal atrophy), mole (low levels due to absence of liver/adrenal - no precursors)
79
DU antigen
Weak D
Same as Rh positive - mom will need Rhogam if fetus DU positive and she is neg
80
What happens to the following in pregnancy?
- Estriol
- Bilirubin
- AST/ALT/GGT
- Alk phos
Estriol - increases
Bili, AST/ALT, GGT - slighly lower
Alk phos - doubles due to heat stable placental alk phos
81
Drug clearance in pregnancy
- Hydrocortisone
- Phenobarb and carbamazepine
- Dilantin
Hydrocortisone - no change in clearance, no increase dose, 20-30mg/day usually
Phenobarb and carbamazepine - increased hepatic clearance 2/2 protein binding (seizure threshold lowered)
Dilantin - serum conc falls in pregnancy, rises in labor and PP
- Total serum concentration declines due to falling albumin levels. Free levels unchanged
82
Hereditary risk of eclampsia
Sisters and daughters of eclamptics 25-37% risk of preE and 3-4% risk of eclampsia with G1
83
Neonatal Graves - sx, treatment
Goiter - can obstruct airway
Jaundice, thrombocytopenia
Treatment - thionamides, BB, iodine
- Methimazole in neonates - PTU has more frequent and severe side effects in childhood
84
Prenatal diagnosis of T21
80% in <35 yo
Triple screen - 60%
85
Prenatal dx of CF
75% are delta F508
- If neg mutation on standard, consider linkage analysis
Allele R117H more common w/ b/l absence of vas deferens
Dx w/ PCR, PAGE
86
How to treat mag toxicity?
Calcium gluconate 10ml of 10% solution over 3 min
Half life of mag = 4h
87
Most common neonatal infection?
CMV
- DNA herpesvirus
- If primary, 40% transmission rate
- Of these, 10-15% with disease, most asymptomatic
- Of disease, 90% have sequelae, 10% normal
- Of asx, 5-15% develop sequelae
88
Asthma in pregnancy
- What drug can cause bronchospasm?
- Rates of worsening?
Indomethacin can cause bronchospasm
30% worsen in pregnancy
60% - behaves similar in subsequent pregnancies
1-10% exacerbations during labor, 18x higher for CD
10% risk of PEC, 10% IUGR, 7% PTD, 2% GDM
89
US safety levels
ALARA
No malformations w/ diagnostic US
Set lower than safe elvel - <100mW/cm2 unfocused, <1W/cm2 focused
Watts per square cm = intensity
90
Delta OD450 - what is it and what does it predict?
Bilirubin in amniotic fluid due to fetal hemolysis - reaches AFI from pulmonary secretions and diffusion
- Bili shifts density w/ peak at 450nm
- Estimates degree of RBC hemolysis
Amniotic fluid delta OD (optical density) 450 values accurately predict severe fetal anemia in D-alloimmunization
91
Amnio for fetal lung maturity values:
Sphingomyelin - not related to FLM
Lecithin rises w/ GA and S falls
- L/S >2 is normal, significant for appropriate fetal lung development
RDS 73% of L/S <1.5
- 50% L/S 1.5-1.9
- 2% if >2
PG (phosphatidylglycerol) - appears at 35wks if mature
- Can be used w/ blood or mec
PI (phosphatidylinositol) - decreases as PG appears (share a precursor, CDP diacylglycerol)
92
Most common local anesthetics used in epidurals?
Bupivicaine (marcaine) and chloroprocaine
- Bupivicaine - longer half-life, delayed onset
- Combine w/ narcotic for less motor blockade
Continuous epidural infusion a/w late decels - more common w/ bupivicaine than chloro or lido
93
Cholinesterase deficiency
Can't metabolize esters (local anesthetics=caines)
Autosomal recessive - fetus could be affected
94
Folate
- Dietary sources?
- Where is it stored?
- S/sx of deficiency?
Water soluble
Greens, peanuts, liver
Stored in liver x 6wks
- Levels fall after 3wks deficiency
Hypersegmented neutrophils -> RBC folate drops -> megaloblastic bone marrow
- Hypersegmented neutrophils, followed by macrocytosis, followed by anemia
Most common cause of megaloblastic anemia in pregnancy
- Increased need for folate in pregnancy due to fetal demand, decreased gastric absorption
95
Hemoglobin electrophoresis in beta thal minor
Increased A2 >3.5%
Increased F >2%
96
Hemoglobin electrophoresis in S-beta thal
S 70-95%
F < 20%
A2 >3.5%
Some hgbA (if beta thal plus)
97
Hemoglobin electrophoresis in SCT
S 30%
A > S
- A:S ratio usually 60:40
98
Hemoglobin electrophoresis in Hgb SC
50% S
50% C
99
Hemoglobin electrophoresis in Hgb SS
>90% S
<10% F
No A
100
What are next steps in pregnancy w/ IUD in place?
Remove
- 54% SAB, 20% IUGR if left in place
- Risk of septic AB
- 25% SAB if removed
101
Uterine anomalies - risk to pregnancy
Survival
- 58% bicornuate
- 65% septum
PTL
- 37% unicornuate
- 20-80% bicornuate
- 4-17% septum
29% of all ended in loss
102
Drugs contraindicated in breastfeeding
Amantidine
Amiodarone
Chemo
Bromide
Cocaine
Chloramphenicol
Dipyrone
Gold salts
Iodide
Radioactive
Large dose ASA
103
What decreases fetal breathing?
PGE2 (labor
Narcotics
104
What increases fetal breathing?
Indomethacin
Theophylline
Increased core temp
105
Spermicide
Nonoxyl-9
Next to cervix, effective 1hr max
High failure rate
106
Cause of bleeding from umbilical cord stump
Testing
Immediate = platelets
Delayed = soluble component disorder (factor VIII)
Oozing >2d after dental procedure = vWD
PTT intrinsic (VIII or IX)
PT extrinsic (V, VII, X)
Bleeding time (platelet # and function)
Clotting time (fibrinogen)
- No clot in 10min means <50mg/dL
Normal coag screen - either factor XIII deficiency or vascular abnormality
107
Intracranial venous occlusive disease
- When does it occur?
- Symptoms?
- LP results?
- How to diagnose?
- Prognosis?
- Treatment?
3rd trimester or PP
Sx - HA, paresis, focal/generalized seizures, drowsiness, confusion, fever, speech/vision/sensory disturbance
- Intermittent HTN
- Suspect if isolated HA w/o other evidence of preeclampsia
LP - increased CSF pressure, protein
Dx w/ CT or MRA
1/3 die, can recur
Tx - dex?, mannitol, anticonvulsant, heparin to prevent extension
108
Sensitivity
Disease correctly identified by positive test
TP/TP+FN
109
Specificity
Healthy correctly identified w/ negative test
TN/TN+FP
110
PPV
True positives of those who test positive
TP/TP+FP
111
NPV
True negatives of those who test negative
TN/TN+FN
112
Treatment of thyroid storm
ICU
Supportive care - fluids, correct lytes, O2 if needed, tylenol for fever
PTU (preferred - more rapid onset, inhibition of conversion of T4 to T3)
Beta blocker
Iodine 1hr after thionamides
Steroids to reduce peripheral conversion
ASA can increase thyroid hormones
Dig if CHF
Abx if infection
113
Renal transplant in pregnancy
Should wait 18-24mo before pregnancy
- Ok if minimal proteinuria, no HTN, no rejection, no calyceal dilation, Cr <1.4
Sequelae:
- 40% SAB in 1st trimester
- 9% serious rejection
- 45-60% PTD
- 30% PEC
- 20% IUGR
Pregnancy has no effect on graft function
10% will die w/in 7 years of pregnancy, 50% w/in 15 years
114
In utero exposure to hep B - cancer risk
40% risk in chronic carrier infected neonatally
115
In utero exposure to DES - cancer risk
1/1000 - incomplete carcinogen
116
In utero exposure to cyclosporin, cyclophosphamide - cancer risk
No cancer risk
117
Seizure med teratogenisis
Most common anomaly = cleft
CHD - risk higher on meds, polytherapy
118
Prostaglandins for IOL
- What are prostaglandins?
- Precursors?
- Half-life?
- What makes F2, E2, prostacyclin?
- What do E and F do?
Bioactive lipids; hormone-like function; E and F are paracrine/autocrine hormones
Precursors - arachidonic acid and fatty acids
Half-life 1-2min
F2 - maternal decidua
E2 - fetal membranes (amnion)
Prostacyclin - myometrium
F - promotes contractions
E2 - cervical maturation
119
Progesterone synthesis
Syncytiotrophoblast uses maternal cholesterol to make pregnenolone (or uses fetal pregnenolone), which is converted to progesterone by 3-beta-steroid dehydrogenase (fetus doesn't have 3-b-OH-d)
- Progesterone passes into fetal circulation, metabolized in fetal adrenal into corticosteroid sulfates
- Passes into maternal circulation - makes uterus quiescent
Placenta can't convert pregnenolone or progesterone to DHEA - lacks 17-alpha-hydroxylase
120
Estrogen synthesis in pregnancy
Fetus uses LDL to make DHEAS in adrenals
- Sends to placenta - converts to androstenedione -> estrone and testosterone -> estradiol
DHEAS sent to fetal liver - converted to 16-a-OH DHEAS
- Sends to placenta - 16-OH androstenedione -> estriol
Placenta lacks 17-a-hydroxylase, so it can't produce estrogen de novo from cholesterol and can't convert progesterone to DHEAS
121
Hyperparathyroidism - maternal effects
Fatigue, N/V, constipation, dyspepsia, polyuria, nephrolithiasis, pancreatitis, HTN, bone disease
Treatment - hydration, loop diuretics, oral bisphosphonates, calcitonin (opposes PTH), mag, sometimes dialysis
122
Hyperparathyroidism - fetal effects
Hypocalcemia/tetany (suppression of fetal PTH), prematurity, SAB
High rate of complications and death
123
Mortality of maternal cardiac disease by groups
Group 1 - minimal disease
- 0-1% mortality
- NYHA I/II
- ASD, VSD, PDA, corrected tet, bio valve,
Group 2
- 5-15% mortality
- NYHA III/IV
- AS, coarc w/o valve involvement, uncorrected tet, prior MI, Marfan w/ normal aorta
- MS w/ afib, artificial valve = worse
Group 3
- 25-50% mortality
- PHTN, coarc w/ abnormal valve, Marfan w/ abnormal valve, Eisenmengers, PP cardiomyopathy w/ persistent decreased LV function
124
Mechanism of contractions (cAMP)
Beta 2 adrenergic receptors (R) on uterine smooth muscle.
Stim of R 🡪 adenylate cyclase via stim of G protein 🡪 increased cAMP 🡪 protein kinase A 🡪 myosin light chain phosphorylation 🡪 also decreased Ca entry and increased Ca efflux. Net result is relaxation.
125
Neonatal adaptation to extrauterine life
First few breaths make FRC
Clearance of fluid - chest compression when passing through birth canal
Expansion of lungs stimulates surfactant release, which stabilizes FRC
PVR decreases -> increased flow to lungs
Low placental resistance closes off circulation and establishes high resistance systemic circulation to reduce R->L shunt through DA/FO
Increase in PaO2 -> closure of DA
126
UA Dopplers
Measurements taken near placental insertion have lower resistance
- Resistance higher at abdominal insertion
- Dopplers are worse at UCI than PCI
Don't always have diastolic flow <15wks
Breathing can affect Dopplers (make them better?)
127
Hepatitis B timeline (serology)
HBsAg 🡪 HBeAg 🡪 HBcIgM🡪 anti HBe 🡪 core IgG 🡪 HbsAb
HBsAg, then HBeAg
Anti-HBc (anti-core) IgM
Anti-HBe
Anti-HBc IgG
Anti-HBs (anti-surface) = immunity
128
Mechanism of action - methyldopa
Central alpha2 receptor agonist
Reduces SVR
CO/renal flow unchanged
Side effects - dry mouth, drowsy, lethargy, LFT abn, hem anemia, +Coombs, postural hypotension
129
Mechanism of action - Clonidine
Potent alpha2 adrenoreceptor agonist
- Decreases norepinephrine release from central and peripheral sympathetics
Rebound HTN
CO/renal flow unchanged
Urinary secretion
130
Mechanism of action - Prazosin
Alpha 1 blockade
Vasodilates to reduce preload and afterload
Renal flow unchanged
Metabolized in liver, 2-3h half-life
Side effects - fluid retention, orthostasis, congestion
131
Mechanism of action - CCB
Inhibit calcium influx to block smooth muslce contraction
Vasodilation, reduction in PVR
CO/renal blood flow unchanged
Side effects - flushing, peripheral edema, dizziness, HA
132
Mechanism of action - ACEi
Blocks angiotensin II
Vasodilation
Inhibits bradykinin
133
Mechanism of action - Hydralazine
Direct peripheral vasodilator acting on vascular smooth muscle
Increases CO
Renal blood flow unchanged
Side effects - fluid retention, tachycardia, palpitations, HA, SLE, neo thromb
Half-life 3h
134
Mechanism of action - Labetalol
Beta blocker
CO and RBF unchanged
Side effects - tremulousness, flushing, HA
135
Mechanism of action - Thiazide
Takes 3-5d for 3-5% reduction in plasma and extracellular volume
Decreased CO, return to baseline after 1mo
Long term decrease in PVR afterward - decreased sodium in smooth muscle
136
What increases risk of aspiration from anesthesia?
>25ml in stomach or pH <2.5
Uterus - increases intragastric pressure
GES less competent
Delayed gastric emptying (low motilin)
Increased gastrin (more acidic, volume higher)
137
What is the risk of conversion to SVT with PACs?
1%
138
Most common risk factor for brachial plexus injury
Prolonged labor/difficult delivery?
139
Cocaine teratogenic effects
Skull defect, cutis aplasia, porencephaly (due to bleed), heart defects, atresias, UT abnormalities, bowel/limb infarct
SAB/IUFD
140
When can a fetus respond to sound?
Hearing organs 24wks
Brain response 26-28wks
141
Why is hypoxia during intubation faster in pregnancy?
Increased metabolic demand, reduced FRC - reduced O2 reserve
- Hypoxia happens more rapidly if ventilation or CO become inadequate
142
Triploidy - sequelae
Holoprosencephaly, ventriculomegaly, ACC, NTD, facial abn, IUGR, SUA, syndactyly, CHD, GU abn
143
Type 1 triploidy
Diandric - add'l chromosome set is paternal
Large cystic placenta, IUGR, elevated hCG/AFP/Inhibin
144
Type 2 triploidy
Digynic - add'l chromosome set is maternal
Small non-cystic placenta, IUGR, low hCG/estriol
145
Symptoms of renal transplant rejection
Fever, oliguria, abn labs, CVA tenderness, renal enlargement
Can only r/o w/ biopsy
Follow w/ serial labs
146
Why don't anti-lewis antibodies cause HDFN?
Not true erythrocyte antigens
Secreted by other tissues and absorbed on RBC surface. Fetal erythrocytes acquire very little antigen in utero and react very weakly to anti-Lewis.
147
Physiology of aortic stenosis
Without valve replacement, 50% survive 5 years after angina, 3 after syncope, 2 after LV failure
Pregnancy - may have increasing exercise intolerance
Gradient of 60 or less do well
Excess LV overload. Ventricular hypertrophy increases cardiac O2 requirement. Increased diastolic pressure impairs coronary perfusion. LV requires adequate filling to generate sufficient systolic pressure to produce flow across valve. Small loss of LV filling results in large fall in CO - very sensitive to loss of preload (hemorrhage, epidural). Pulmonary edema d/t excess preload better tolerated than hypotension/hypovolemia.
148
Major cause of ureteral dilation in mom?
Begins 2nd month, peaks 2nd trimester
2cm diameter
Compression by ovarian plexus and uterus
Progesterone/smooth muscle relaxation contribute
More prominent on R - dextrorotation of gravid uterus, engorged R ovarian vein
149
Placental glucose
70% of glucose taken up by uterus consumed by placenta
1/3 converted to lactate (fetal energetic substrate)
Aerobic
150
Prolactinoma in pregnancy
Stop bromocriptine unless levels >200 or abnormal MRI
No a/w congenital anomalies
Complications - 1-4% w/ microadenoma, 35% w/ macroadenoma
Worsening s/sx - visual field testing, MRI if abn
151
HPV transmission to fetus
Causes laryngeal papillomatosis in kids
5-30% oropharyngeal transmission
3% infants seropositive at 1-2yrs
152
Aromatase deficiency
Androstenedione not converted to estradiol
- Excess ASdione secreted to mom and baby causing virilization
- Males have delayed puberty and tall stature
153
What can accelerate fetal lung maturation?
Steroids
TRH
T3
Beta agonists
Prolactin
EGF
TGF-alpha
154
What can delay FLM?
Androgens
Insulin
TGF-beta
155
Dose of thioamide during thyroid storm?
PTU 300mg q6h
156
Absent stomach - DDx
1% of normal fetuses
Esophageal atresia
TEF
CDH
Clefts (impaired swallowing)
CNS disorder
Arthrogryposis
TTTS
T18
Triploidy
Renal agenesis
Oligohydramnios
157
Polycystic kidney disease - types
Type 1
- AR, infantile
- Big kidneys, cysts not visible
- Oligo, hepatic fibrosis
Type 2
- MCDK
- Failed development of metanephros
- No normal tissue
- Contralateral abnormal in 40%
Type 3
- AD, adult
- Renal failure in 5th decade
- Berry aneurysm
Type 4
- Obstructive cystic dysplasia
- Small, cysts, hydro
Syndromes - Meckel Gruber, T13, Beckwith-Wiedemann, Tuberous sclerosus
158
Most common antenatal finding in toxo?
Ventriculomegaly
Also - intracranial calcifications, liver calc, ascites, hydrops, placentomegaly
159
Most important factor influencing Apgar?
Gestational age
160
What does confidence interval mean?
95% probability that the interval contains the population mean
- Contains true RR w/ 95% confidence
161
RR vs OR
RR - risk of exposed to risk of non-exposed
- (a/a+b)/(c/c+d)
OR - odds exposure in diseased group divided by odds exposure in non-diseased group
- ad/bc
- Used in case control - approximates RR when cases are representative of all w/ disease, controls represent population, and disease infrequent
162
Management of vWD
Check factor VIII levels periodically
Pretreatment if <50% of normal
163
Test for alloimmune thrombocytopenia?
HPA-1a
164
High dose aspirin in pregnancy
No teratogenesis
Decreased uterine contractility
Newborn platelet dysfunction if taken within 5 days
Closure of fetal DA
165
Fragile X
Most common cause of familial intellectual disability
FMR1 gene
CGG repeats
- Can only expand when transmitted by female
Premutation - 56-229
20% asymptomatic and non-transmitting
Not perfect transmission 2/2 mosaicism and ionization
166
TTP symptoms
Pentad:
- MAHA
- Thrombocytopenia
- Neurologic abnormalities
- Fever
- Renal
167
Preeclampsia is associated w/ what changes in:
- Renin
- Fibronectin
- Ang II
Renin/angII/ald - all decrease in PEC (normally increase in preg)
Fibronectin - increased 2/2 endothelial damage
Ang II - increased vascular sensitivity
168
Exercise to the point of exhaustion is not recommended in pregnancy because...
If prolonged, increases fetal heart rate (5-15 bpm). Reduced birth weight 2/2 decreased fat. Changes in uterine blood flow compensated by hemoconcentration to increase O2 carrying capacity and increased placental oxygen extraction.
169
Phospholipase A2 - mech of action
What bacteria is associated?
Cleaves arachidonic acid from fetal membranes to make it available for prostaglandin synthesis
Bacteroides, peptostrep, fusobacterium, strep viridans, strep fecalis, GAS and GBS, E. coli, Klebsiella, staph epi
- These bacteria produce phospholipase A2 and can cause PTL
170
Abx for salmonella
Chloramphenicol - most effective
- Also bactrim, amp, cipro, cefotaxime
171
Heroin effects
Increased withdrawal
IUGR, PTD, IUFD, meconium, low Apgars
172
Chi square test
Nominal, proportions, or dichotomous data in contingency table
173
Paired t test
Okay if individuals followed over time to see if there is a change in the value of some continuous variable
Considers variation from one group of people
174
Simple t test
Compare means of continuous variable in two samples to see if there is a difference
175
Mann Whitney U test
Non-parametric to compare two groups of ordinal data (more than 2 values and have implied direction from better to worse but aren’t continuous)
176
Selection bias
When subjects are self-selected into study groups
Commonly seen in studies of treatment methods and terminal diseases
177
Allocation bias
Investigator chooses non-random method of assigning subjects to study groups
May occur if a random method is chosen but not followed
178
Trisomy 20 mosaicism
Most common mosaic trisomy dx with amnio
93% are normal phenotype
179
Paracentric vs pericentric inversion
Paracentric - inversion does not involve centromere, occurs in only 1 arm
Pericentric - inversion includes centromere
Risk of affected child - 1-3%, 5-10% if already have affected child
180
What increases risk of loss w/ CVS?
Fundal placenta
Increased # of passages
Prior bleeding
181
Myotonic dystrophy
Autosomal dominant
Most common cause of adult myopathy
Wide age of onset
Unstable CTG repeats, chromosome 9
- 3-30 repeats normal
- Can increase via transmission from either parent
Fetal effects - poly, arthrogryposis
Affected moms - SAB, PTL, poor uterine contractions, hemorrhage
Regional anesthesia preferred
Dx made by DNA probe
182
Beta thal
A2 >3.5%, F >2%
Chromosome 11
Major - Cooley's anemia, hemolysis, need transfusions
- Neonate healthy until HgbF falls (6mo)
- Improved w/ deferoxamine
- Some need BM transplant
Minor - hypochromia, microcytosis, slight to mod anemia
183
vWF
Platelet adhesion to subendothelial collagen and formation of hemostatic plug
184
Symptoms of TTP
90% have neuro sx
- HA, backache, AMS, convulsions, stroke
185
Lupus anticoagulant
Prolongs PT, aPTT and RVV times
186
Beta2 glycoprotein
Anticoagulant inhibition of prothrombinase activity of platelets
High concentration in syncitiotrophoblast
Can prevent implantation or 🡪 intervillous space thrombosis
187
Myasthenia - what local anesthetic to use?
No procaine if taking AChE blockers - convulsions since not metabolized
Lidocaine ok
188
Erythema migrans
Lyme disease
PCN
- If allergy, cefuroxime or erythromycin
189
Desquamating rash
Toxic shock syndrome
- Exotoxin TSS toxin-1
- Renal/liver failure, DIC
Rash when recovering
190
Cold agglutinin
Mycoplasma or mono - can cause autoimmune hemolytic anemia
191
PCN resistant bacteria?
Mycoplasma - use macrolide
192
What is not a/w DES?
Ectopic
SAB
PTL
Cervical insufficiency
Corrected perinatal mortality
Corrected perinatal mortality
193
Peripartum cardiomyopathy - mortality
25-50% - CHF, arrhythmia, VTE
50% resolve in 6mo
- Of those who don't, 85% die in 4-5yrs
194
Drugs that affect efficacy of OCPs
rifampin, phenobarb, phenytoin, primidone, carbamazepine, ethosux, Griseofulvin, troglitazone
195
OCPs can potentiate action of:
diazepam, chlordiazepoxide (Librium), TCAs, theophylline, BBs, caffeine, steroids, ETOH
196
OCPs an decrease efficacy of:
Tylenol, ASA, benzo, methyldopa, oral anticoag, oral hypoglycemic
197
Platelet disorders in pregnancy:
- Highest maternal mortality
- Maternal plt count normal
- Corrected w/ plasmapheresis
- Low neonatal/fetal counts
Highest maternal mortality: TTP
Maternal platelet count normal: NAIT
Corrected with plasmapheresis: TTP
Low neonatal/fetal counts: ITP, alloimmune, thiazide
198
Factor XIII deficiency
AR
Commonly fatal in affected infants
ICH from trivial trauma, poor wound healing
Coags normal
Dx by dissolution of clot in urea
Treat w/ FFP, whole blood, cryo
199
What heart defect causes cyanosis in pregnancy?
Tetraology
- SVR decreases in pregnancy, shunting worsens
200
Cardiac defect w/ highest maternal mortality?
PHTN
Coarc w/ valve abnormality
Marfans w/ aortic involvement
201
Cardiac defect treated w/ propranolol?
IHSS (those w/ angina, SVT, or arrhythmia)
202
Cardiac defect affected by shortened diastole?
MS - shortens filling time and increases mitral gradient -> pulm edema
203
Blood gas alterations w/ variable decels
Transient cord compression - causes respiratory acidosis
204
Arginine vasopressin causes what FHR pattern?
Sinusoidal
205
Components of cryo
Factor VIII, XIII, vWF, fibrinogen
206
Meperidine half-life
3.5h
207
Tay Sachs - how to diagnose, enzyme affected
CVS or amnio for enzymatic assay or molecular analysis
Lack hexosaminidase (test is for enzyme level in blood)
Death in 1st decade
Carrier detection by serum leukocytes
208
Which is d/t a gene deletion?
Sickle cell
Beta thal
Alpha thal
Alpha thal
Others - mutation
209
How to diagnose PKU
Molecular methods - testing level of Phe in blood (don't have to test DNA)
210
Hurler syndrome (Mucopolysaccharidosis)
AR
Deficiency of alpha L iduronidase
Activity measured by amnio
211
What neonatal infections are associated w/ deafness?
CMV
Rubella
212
Homologous translocation
Only have abnormal gametes
- Cause trisomy or monosomy
213
How much do ppx antibiotics at time of Cesarean decrease infection?
50%
mostly wound and uterine
214
Causes of increased twinning
Race
Hereditary
Age
Parity
Fertility drugs (dizygotic)
215
Incidence of chromosomal abn in SABs
45-60%
216
Single most important aspect to genetic counseling:
Pedigree
217
Proportion of infants w/ T21 born to women under 35
80%
218
Linkage analysis
A gene-hunting technique that traces patterns of disease in high-risk families. It attempts to locate a disease-causing gene by identifying genetic markers of known chromosomal location that are co-inherited with the trait of interest
- Identifies a specific chromosome w/ closely linked polymorphism
At least 1 affected member, the family member at risk, and 1 or both parents must be tested
219
Limb defects in trisomies
T13 > T18 > T 21
220
Accuracy of fetal echo?
Sensitivity 85%
- False negs w/ minor anomalies like small VSDs
- False pos w/ coarcs and VSDs
221
What is obstructive cystic renal dysplasia?
Also called Potter type IV
Complication from prolonged obstruction of bladder outlet or urethra
Small kidney, fibrous tissue, cortical cysts
Unilateral - UPJ or UVJ obstruction
Bilateral - severe urethral atresia, PUV
222
Microcephaly diagnosis
HC 3 SD below mean
33% with ID if HC 2-3 SD below, 62% if <3 SD
223
Heparin side effects
Hemorrhage w/ lacs
HIT - 3-6%, manifests in 2-3wks
Osteopenia - more common w/ higher doses, longer durations, smokers
224
PE - prevalence
Most common sx
Equal prevalence ante and PP, but higher mortality PP
Most common sx - dyspnea, chest pain, then cough
Most common findings - tachypnea, dyspnea, pleuritic pain
225
Equivocal HIV testing
Considered positive with both +ELISA and western blot
Repeat test later
PCR can be useful to detect virus
226
HIV epidemiology
Most common - sexual transmission, then IVDU
227
Which has a decreased maternal serum concentration?
Insulin
FFA
Estradiol
PTH
Amino acids
Amino acids - due to placental uptake
228
Umbilical venous blood characterized by:
Higher pO2 than intervillous space
Higher pCO2 than UA
Lower pO2 than intervillous space
Lower pH than UA
Lower hgb than uterine artery
Lower pO2 than intervillous space
- Venous blood is going back towards fetus - needs to be lower than intervillous space or else oxygen wouldn’t simply diffuse into the venous blood
229
Classification of human placenta?
Hemochorioendothelial – maternal blood directly bathes syncytiotrophoblast
230
What GA is AFI at max?
34wks
231
Forceps
Kiellands: no pelvic curve
Barton: platy pelvis. Traction of head in transverse position
Tucker McClanes: Non-fenestrated and overlapping shanks
Simpsons
Elliot: fenestrated, overlapping shanks, greater pelvic curve than Simpsons
232
Most common perinatal complication of PPROM?
RDS
Most common cause of death = prematurity
233
What is the evaluation of an Rh negative mother?
Indirect Coombs = maternal antibody detection
Direct Coombs = evaluates fetus
- Detects antibodies attached to RBCs
234
Most common cause of neonatal death?
Major anomalies
235
Amniotic fluid composition
Osmolality falls w/ increasing GA to 250-260 near term
UA, urea, and creatinine increased
Protein declines after 32wks
236
Immune globulin should be given to pregnant women for:
Hep A
Rubeola (measles) - w/in 3 days
Hep B
Varicella - w/in 96h
237
Contraindication to breast feeding?
CMV
HSV
HBV
HCV
HIV
Mastitis
Mastitis
238
Contraindication to beta mimetics
Absolute - maternal cardiac dz, severe preE, antepartum hemorrhage, uncontrolled DM, hyperthyroid
Relative - controlled DM, HTN, h/o severe migraines, increased risk of pulm edema
Beta mimetics (terb) - stimulate B2 adrenergic receptors, increase maternal HR and CO, produce peripheral vasodilation
239
Risk factors for vasa previa
Velamentous insertion
Low lying placenta
Accessory lobe
Multiples
IVF
240
Asthma in pregnancy:
Severity likely to increase
Increased risk of PTD
Long term corticosteroids contraindicated
Theophylline for acute asthma management
Increased risk of PTD
241
Prophylaxis against aspiration PNA
Fasting, antacid to reduce gastric acidity, cricoid pressure (Sellick).
242
Best anesthetic for asthmatic
Epidural w/ local/opioids - pain relief and avoidance of resp depression
Narcotics and ET can cause bronchospasm
If general must be used, ketamine doesn't release histamine and is better
Depolarizing agents can cause bronchospasm
243
Gut migration in embryonic development
At 8 weeks (6 fetal weeks), herniation occurs d/t midgut loop
Returns by 12 weeks or 61 mm CRL
244
Contraindication to regional anesthesia:
Cardiac conditions that won’t withstand reductions in SVR: AS, PHTN, cyanotic lesions
245
Highest flow rate in fetus:
Umbilical artery
Descending aorta: 67% of total cardiac output
Ascending aorta
Pulmonary artery
Pulmonary artery
246
Etiology of preE
Spiral arteries
- Usually invade endovascular trophoblast. In preE decidual vessels but not myometrial vessels are invaded by endovascular trophoblasts.
- Magnitude of defective trophoblast invasion of spiral arteries correlated with severity of preE
247
Highest hemoglobin oxygen saturation in fetus?
IVC
LA
RA
LV
RV
LA (70)
248
Contraindications to OCPs
Absolute - VTE, bad liver, breast cancer, undx vag bleeding, pregnant, smoker >35
Relative - fibroids, GDM, elective surgery, epilepsy on meds, obst jaundice in preg, SCD/trait, DM, gall bladder dx
249
Meckel-Gruber
AR
Cystic dysplasia of kidney (100%)
Postaxial polydactyly (55-75%)
Occipital encephalocele (63-80%)
250
Most common complication of subclavian line placement?
Pneumothorax
251
Hunter syndrome
Mucopolysaccharidosis II
XR
Gargoylism - course facial features
ID, skeletal abn, short stature
252
ROC curve
Y axis = sensitivity
X axis = 1-specificity (false positive rate)
If sensitivity = false pos rate, diagonal straight line results, which is of no benefit; upper left would be best
253
Risk of NTD w/ valproate
1.5%
254
SBE prophylaxis - indications
Cyanotic heart disease unrepaired or incompletely repaired
Previous endocarditis
Surgical shunts
Artificial valves
Transplant w/ bad valve
Don't need for C/S unless chorio
255
Most common anomaly w/ diabetes?
CHD
Next - CNS
256
Most frequent complication to preeclamptic receiving epidural?
Hypotension
