MFM Flashcards
How much does blood volume increase during pregnancy and when?
Increases by 30-50%
Starts to increase 1st trimester
Largest increase 2nd trimester
Rise slows during 3rd trimester
Why does maternal blood volume increase during pregnancy?
Increases preload to:
- Protect from impaired venous return
- Meet increased demand from growing uterus
- Protect against delivery blood loss
How does BP change during pregnancy?
Decreases during 1st trimester
Lowest during 2nd trimester
Widened pulse pressure
How does cardiac output change during pregnancy?
Increases 30-50%
Greatest in lateral recumbent position due to improved venous return
What respiratory changes occur during pregnancy?
Rate remains stable
Tidal volume and minute ventilation increase significantly
Residual volume decreases
Progesterone–> chronic hyperventilation/v PaCO2
How do the kidneys adapt to pregnancy?
Hypertrophy: calyces and ureters dilate
Increased GFR and renal blood flow (^50%)
Decreased renal bicarb threshold–>Increased protein filtration
Increased ADH, renin, angiotensis II, aldosterone
How do RBC’s change during pregnancy?
Total number increase by 30%
Production increases due to increased iron demand
Increased cell volume
Plasma» RBC increase–> dilutional anemia
What changes are seen in WBC’s during pregnancy?
Increased estrogen-> leukocytosis
Decreased leukocyte function
What changes are seen in platelets during pregnancy?
Counts remain stable
Width and volume increase (due to rapid consumption and replacement)
How do hemoglobin and hematocrit change during pregnancy?
Dilutional anemia + increased erythropoiesis –>
slightly decreased Hgb/Hct
Why is there a greater risk of thromboembolic disease and pregnancy?
Increased coagulation factors
Fibrinogen increases 30 to 50% due to estrogen
Decreased fibrinolysis
What are the changes to the GI tract during pregnancy?
Displaced stomach and intestines
Decreased gastric emptying time, altered stomach position, decreased lower esophageal sphincter tone
Hemorrhoids, increased venous pressure
Impaired gallbladder contraction
What alters endocrine function during pregnancy?
Pituitary gland enlargement by 135%, increased prolactin
Increased thyroxine binding globulin, increased total t4, decreased TSH
Increase in PTH related hormone, increased calcitriol and maternal absorption of calcium for transfer to fetus
Estrogen increases pancreatic cell stimulation, increase in insulin, increased lipogenesis / fat storage
What produces HCG?
Synctiotrophoblasts
When do HCG levels peak
First trimester
Human placental lactogen __________ with increasing gestational age
Increases
Human placental lactogen is involved in
Lipolysis and anti-insulin effects
In labor, progesterone
Maintains a stable level but decreases functionally through decreased receptor and co activator numbers
Progesterone’s immune functions in pregnancy include:
Anti inflammatory
Immunosuppressive to prevent fetal rejection
Estrogen pregnancy functions include
Fetal organ maturation
Uterine endometrium proliferation
Strengthens uterine contractions
From uterine wall to amniotic fluid, the layers of the placenta structure are
Myometrium Decidua basalis Chorion Cotelydon/villi Endometrial arteries Intervillous space Villus Chorionic plate Amnion Umbilical cord
Placenta previa increases the risk of _______ by x _______ factor
Fetal anomalies
2.5 times
Risk of placenta previa is increased by what maternal lifestyle factor?
Maternal smoking
What GU mass increases the risk of placental abruption?
Uterine leiomyoma
What blood marker will be increased in the setting of abnormal placental adherence including placenta accreta increta and percreta?
Serum alpha feto protein
Complete molar pregnancy is characterized by
Larger than gestational age uterus
No fetus
46 XX of paternal origin
Partial molar pregnancy is characterized by
Smaller than gestational age uterus
Non-viable fetus
69 XXX, XXY, XYY
Choriocarcinoma is characterized by
Malignant trophoblastic growth
Hemorrhage or necrosis
Metastasis to lungs or vagina
Elevated beta HCG
True or false chorioangioma is a benign placental tumor?
True
Placental metastases can originate from
Melanoma Leukemia Lymphoma Breast cancer Lung cancer (carcinoma or sarcoma)
The average length of an umbilical cord is
30-100 cm
An umbilical cord length of _____ is associated with poor outcome
< 30cm
Single umbilical artery occurs in _____ percent of infants and is more common in ______
0.5-1%
Twins
Mortality rate of vasa previa is _______
50-90%
Serum markers of maternal lupus include
Anticoagulant antibodies
anticardiolipin antibodies
Maternal ribonucleoprotein antibodies associated with lupus are
Anti-rRo, SSA
anti-La, SSB
Maternal lupus can often present with
Fetal heart block
In maternal lupus, presence of _____ increase risk of fetal heart block
Anti-Ro and anti-La antibodies
Antibodies present with the diagnosis of myasthenia gravis are
90% antibodies to acetylcholine receptors
Myasthenia gravis may exacerbate the maternal disease of
Lupus
Fetal anomalies that may be associated with myasthenia gravis
Arthrogryposis
Transient neonatal myasthenia gravis typically presents by _____ and resolves by _____
12-48h 15 weeks (avg duration 18 days)
If needed neonatal myasthenia gravis can be treated with
Anti-cholinesteraces
Maternal ITP typically has platelet counts of ______ and does / does not affect the fetus
<70k
Does not
Can cause neonatal autoimmune thrombocytopenia
The risk to the fetus in the setting of maternal ITP is increased
Intraventricular hemorrhage
Advanced maternal age has an increased risk of what four syndromes?
Trisomy 13
Trisomy 18
trisomy 21
Klinefelter syndrome
Gestational hypertension is defined as
Hypertension without proteinuria after 20 weeks gestation and return to baseline blood pressure by 12 weeks postpartum
Preeclampsia is defined as
Hypertension and proteinuria during pregnancy
Chronic hypertension is
blood pressure increases noted prior to pregnancy and persisting beyond 12 weeks postpartum
Preeclampsia is differentiated from chronic hypertension
New onset proteinuria during pregnancy
Will occur in approximately 25% of women with chronic hypertension
Preeclampsia effects ____ percent of all pregnancy and recurs in up to _____ percent
5-10%
65%
Risk factors for a preeclampsia
First pregnancy Multiple gestation Measure uterine anomalies Chronic hypertension Chronic renal disease Prior episode of preeclampsia
What is the cause of preeclampsia
Decreased trophoblastic invasion with less dilated spiral arteries
Decreased uterine placental blood flow leading to placental ischemia
Cytokine release
Increased blood pressure and fibrin deposition
Inhibited angiogenic activity due to increased soluble FLT1
HELLP syndrome is defined as
Hemolysis
Elevated liver enzymes (AST >70, LDH >600, TB >1.2)
Low platelets (plt <100k)
Glomerulonephulosis is/ is not reversible postpartum
Is
Early in gestation AFP is produced by the
Yolk sac
Later in gestation AFP is produced by
Fetal liver and GI tract
Fetal AFP peaks at ____ weeks
13
Maternal AFP peaks at ____ weeks
32
Greatest sensitivity for AFP screening is at ____-_____ weeks
16-18
AFP is elevated in these 4 situations:
Neuro (NTD)
GI: (obstruction, omphalocele, gastroschisis)
Renal: (polycystic kidneys, renal aplasia, nephrotic syndrome, cloacal exstrophy, obstruction)
Masses: (pilonidal cyst, cystic hygroma, sacrococcygeal teratoma)
Also: low birth/maternal weight, oligohydramnios, multiples, incorrect GA, osteogenesis imperfecta, placental chorioangioma
Decreased AFP is concerning for
Trisomies
Gestational trophoblastic disease
After finding an elevated AFP the next step is
Ultrasound
An abnormal nuchal translucency measurement is
> 3 mm
Sensitivity of PAPP-A screening is
60-65%
at 10-13 weeks
Must know maternal age
Nuchal translucency is most commonly a marker of
Cardiac anomalies
Nuchal translucency and PAPP-A screening are ____% sensitive for trisomy 18 and ____% for trisomy 21
91%
78-89%
Trisomy 21 quad screening shows
Increased beta HCG and inhibin A
Decreased uE3, AFP
Trisomy 18 quad screening shows
Decreased B-HCG, uE3, AFP
Inhibin-a minimally impacted
Trisomy 13 quad screening shows
equivocal results
Trisomy detection rates with PAPP-A, nuchal translucency and quad screen are
PAPP-A: 60-65%
QUAD: 75%
NT: 68%
COMBINED: 90-95%
QUAD screening with low uE3 and slightly decreased AFP, and HCG is concerning for
Smith lemli opitz
Compare with trisomy 18
Turner syndrome quad screening appears similar to
Trisomy 21
Reverse or absent doppler flow in IUGR fetus develops from
Villous arteriole medial hypertrophy, increased fetal SVR, ventricular dilation/hypertrophy and increased HR
Double bubble on fetal US is associated with
Duodenal Atresia
Annular pancreas
Malrotation
Duodenal stenosis/web
Echogenic bowel is most often
Normal
Can be chromosomal, CMV, CF, meconium peritonitis, GI anomalies, swallowed maternal blood
Ileal/jejunal atresia occur most often
Proximal jejunum, distal ileum
Most sure to intravascular accidents
Meconium peritonitis can be a sign of
CF or intestinal obstruction that causes perforation
Appears as calcifications
Omphalocele should receive additional workup for
Beckwith-Wiedemann
Trisomy 13
Trisomy 18
Cloacal exstrophy
Severe micromelia and lack of vertebral ossification is
Achondrogenesis
The most common skeletal dysplasia is _______ with _____ findings
Achondroplasia
21-27 weeks: Rhizomelia Large head Bossing Protuberant abdomen Trident-shaped head
Skeletal dysplasia with pulmonary hypoplasia is
Thanataphoric dysplasia
Severe micromelia Curved femurs Short, broad ribs Pulmonary hypoplasia Hypoplastic vertebral bodies
In utero fractures are usually the result of
Osteogenesis imperfecta type 2
Dandy Walker malformation is defined as
Cystic dilation of the fourth ventricle
enlarged posterior fossa
obstructive hydrocephalus
cerebellar vermis aplasia
Dandy Walker variant is defined as
Direct communication from fourth ventricle to the cisterna magna without enlargement of the posterior fossa
Can be seen in chromosomal abnormalities like trisomy 13
A mass with an associated school defect is called an
Encephalocele
Encephaloceles occur in what location most commonly?
75% occipital
Encephaloceles are commonly associated with what other system disease
Renal cystic disease
Explain of the posterior ossification centers of the spinal bones that may have a fluid filled sac over the skin is a
Meningomyelocele
Meningitis with an elongated cerebellum will demonstrate a _______ on imaging
Banana sign: crescent shape around brainstem
Meningoidal seal with abnormal concave frontal bones has a _____ sign on imaging
Lemon sign
Seen between 18-24w
Other intracranial findings associated with meningococcal are
Microcephaly
Ventriculomegaly
A large posterior spinal mass that is often cystic and solid is a
Sacrococcygeal teratoma
Sacrococcygeal teratomas are often associated with
Polyhydramnios
What severity of ventriculomegaly is associated with higher risk of mortality and morbidity?
All degrees of severity
Unilateral hydronephrosis is most likely
Unilateral ureteropelvic junction obstruction
Bilateral hydronephrosis is typically due to
Lower urinary tract obstruction I.e. posterior urethral valves
or
bilateral ureteropelvic junction obstruction
Severe hydronephrosis is defined as
Greater than 10 mm dilation in second trimester
or
greater than 15 mm dilation in third trimester
The definition of hydronephrosis begins at ______ dilation in the second trimester or ______ dilation in the third trimester
> 5mm
>7mm
Non-communicating cyst in the kidneys of different size are
Multi cystic dysplastic kidney
40% of multi-systic dysplastic kidneys will be associated with
Contralateral renal anomalies
Bilateral multiple renal cysts with normal renal tissue is
Polycystic kidney disease
Findings of distended bladder with thickened wall and hydronephrosis and oligohydramnios is concerning for
Posterior urethral valves
Non-visible kidney and bladder with severe oligohydramnios is concerning for
Bilateral renal agenesis
Cystic hygromas are most commonly seen in
Noonan syndrome
Turner syndrome
A septated cystic mass or lymphangioma in the neck or occiput is a
Cystic hygroma
Cystic hygromas made less commonly evound in these four syndromes
Deletion 13Q
Trisomy 13
Trisomy 18
Trisomy 21
Amniocentesis is performed at
15 to 20 weeks
Amniocentesis samples
20 to 30 ml amniotic fluid for AFP acetylcholinesterase fetal lung maturity bilirubin Infection
CVS is performed at
10 to 13 weeks
What does can be utilized to determine if a PUBS sample is maternal or fetal?
Clean our bed key test
What testing or therapies can be performed using pubs?
Chromosome analysis
Hemoglobin, IgM/ IGG, bacterial and viral cultures Hydrops evaluation
Transfusion
Fetal drug therapy
What is the rate of fetal loss with amniocentesis?
One in 200, higher if earlier
How long does it take to receive amniocentesis results?
1 to 2 weeks
What is the rate of fetal loss with chorionic villus sampling?
3 in 200, higher if transcervical
Which fetal genetic testing methods require rhogam for Rh sensitization?
Amniocentesis
CVS
What is the rate of fetal loss for pubs?
1.4%
What is the highest risk associated with pubs?
Fetal maternal hemorrhage, 66%
A reassuring NST or contraction stress test indicates
High likelihood of intrauterine survival for 7 days
Components of a BPP include
NST Fetal body movement Breathing Fetal tone Amniotic fluid volume
A BPP score of_______ requires further intervention
8 with low AFV
<6
A BPP score of ____ requires immediate delivery
0-2
Concerning fetal monitoring patterns are
Late decelerations without variability Variable decelerations without variability Prolonged severe bradycardia Sinusoidal pattern Overall lack of variability
What causes saltatory variability and what defines it?
> 25 bpm swings
Caused by acute hypoxia or compression of umbilical cord
What causes variable decelerations?
Umbilical cord compression:
- > hypertension in fetus
- > baroreceptor response
- > vagal deceleration
OR
- > fetal hypoxemia
- > chemoreceptor response/myocardial depression
- > deceleration of HR
Late decelerations are caused by
Uteroplacental insufficiency
Uteroplacental insufficiency leads to
Fetal hypoxemia
- > chemoreceptor response
- > enhanced alpha-adrenergic activity
- > fetal hypertension
- > baroreceptor response
- > parasympathetic response
- > late decelerations
OR
- > myocardial depression
- > late decelerations
AFI is influenced by maternal hormones ____ and _____
Prolactin- decreased amnion permeability
Vasopressin- increases AF osmolality
Polyhydramnios is defined as
AFI >24cm
Severe oligohydramnios is associated with an increased mortality risk to
187/1000
Initial fetal growth is marked by the _______ stage which occurs the first _____ weeks gestation
Hyperplastic
16
The hyperplastic fetal growth stage is marked by an increase in
Cell number
DNA
Impaired hyperplastic growth stage results in
Symmetric IUGR
The second phase of fetal growth is marked by the ________ stage which occurs between ______ weeks gestation
Hyperplastic and hypertrophic
16 to 32
The hyperplastic and hypertrophic stage of fetal growth is marked by increase in blank
Cell number
Cell size
Impaired second stage fetal growth results in
Asymmetric or symmetric IUGR
The third stage of fetal growth is the ______ stage which occurs after _____ weeks gestation
Hypertrophic
32
The hypertrophic stage of fetal growth is marked by increase in
Cellular size
Protein and RNA
Fetal fat and glycogen are deposited
Impaired hypertrophic fetal growth stage results in
Asymmetric IUGR
Greatest PERCENT increase in fetal growth occurs in the ______ trimester
First
Greatest grams per day fetal growth occurs
With increasing gestational age
Hormones that regulate fetal growth are
Insulin
Insulin like growth factor I & II
Epidermal growth factor
How does growth hormone impact fetal growth?
No involvement of fetal or maternal growth hormone
Fetal tissues do not have growth hormone receptors until late gestation
A growth curve showing consistently less than 10% growth throughout pregnancy is most consistent with
Genetic abnormality or familial SGA
A growth curve showing third trimester decrease in growth is concerning for
Preeclampsia
May also be seen in twin and triplets
A growth curve showing normal growth until the second or third trimester at which point growth slows but still remains within normal percentiles demonstrates
Growth restriction due to failure to reach full growth potential
What is the difference between IUGR and SGA?
IUGR is a failure to grow to the genetic potential of a fetus and is always pathologic. Fetus maybe normal growth percentage or small.
SGA is growing at a smaller than expected size and may or may not be pathologic. Fetus is always small compared to population growth curve.
During which stage of fetal growth does maternal nutrition play a role in fetal weight gain?
Third trimester
Hypoglycemia is a bigger risk in babies with symmetric or asymmetric IUGR?
Asymmetric
Fundal height correctly identifies what percentage of IUGR fetuses?
40%
Ponderal index equals
Weight (grams)* 100 / (length (cm))^3
A low ponderal index is suggestive of
Asymmetric growth
Neonatal effects of SGA/IUGR
Depressed immune function Hyperglycemia Hypocalcemia Hypoglycemia Hypothermia Perinatal deprepression Polycythemia
Immunodepression associated with SGA/IUGR are due to
Decreased lymphocyte number in function and decrease immunoglobulins
May persist into later life
Increased catecholamines in SGA/IUGR infants can cause
Hyperglycemia
SGA/IUGR status increases mortality risk by
5-20x
Non-immune fetal hydrops is defined as
Fluid accumulation in at least two fetal compartments
Sites of possible fluid accumulation in non-immune fetal hydrops include
Skin Ascites Pleural effusion Pericardial effusion Cystic hygroma Placenta
Incidence of non-immune fetal hydrops
1/1500-4000
Most common causes of non-immune fetal hydrops
Cardiac, 25% Unknown, 16% Aneuploidy, 16% Genetic syndrome, 11% Twin to twin transfusion syndrome, 10% Pulmonary, 8% Infection, 4%
Not immune fetal hydrops is most commonly identified through further evaluation of
Polyhydramnios
Hypertension
Maternal anemia
Fetal tachycardia
85% of fetuses with hydrops will have the following finding
Ascites, 85%
Evaluation of fetuses with non-immune fetal hydrops should include
Additional ultrasound for abnormalities including Doppler and cardiac views
Blood typing
torch evaluation
hemoglobin electrophoresis
Can consider amniocentesis or pubs
Perinatal mortality of infants with non-immune fetal hydrops is
40 to 90%, worse if oligo or cardiac disease
The most common perinatal complication of non-immune hydrops is
Preterm delivery, 90%
When does division occur in dichorionic diamniotic monozygotic twins?
Prior to day three
When does division occur in monochorionic diamniotic twins?
Between 3-8 days
When does division occur in monochorionic monoamniotic twins?
8 to 13 days
When does division occur in twins who are conjoined?
13 to 15 days
What is the most common chorionicity/amnioticity of monozygotic twins?
Monochorionic diamniotic 70-75%
What type of monozygotic twins are at highest risk for twin to twin transfusion syndrome?
Monochorionic diamniotic
In what percentage of twin pregnancy does single fetal demise occur?
5%
What are the three possible outcomes to the surviving twin if vascular anastomosis are present?
Disseminated intravascular coagulation
Anemia due to vasodilation in demised twin
Cerebral injury to surviving twin as a result of the above
Twin to twin transfusion occurs in ____ percent of _______ twins
5 to 15%
Monochorionic diamniotic
Twin fetus who presents with anemia hypovolemia oligohydramnios and appears to be stuck against the uterine wall with decreased urine output and lower birth weight is concerning for
Donor twin, twin to twin transfusion
Twin fetus who presents with polycythemia hypervolemia polyhydramnios cardiac hypertrophy possibly hydrops and increased birth weight is concerning for
Recipient twin, twin to twin transfusion
Before what gestational age is twinted when transfusion associated with an especially poor outcome?
24 weeks
Hormone changes that occur during labor include
Stable progesterone with decreased function due to receptor decrease
Increased estrogen to strengthen contractions
Corticotropin releasing hormone produced by placenta to induce cortisol release 4 feet of long maturation and alteration in myometrial receptor expression
Prostaglandins E&F synchronize uterine contractions and ripen cervix, increase sensitization to oxytocin
What is the concentration and dosing of IV epinephrine?
1: 10,000
0. 1 to 0.3 ml/kg
What is the concentration and dosing of endotracheal epinephrine?
1: 10,000
0. 3-1ml/kg
What is the most significant risk factor for premature birth?
Previous pre-term delivery, 17 to 40%
Significant risk factors for preterm delivery include
Previous preterm delivery Uterine malformations, 3 to 16% Maternal history of DES exposure, 15 to 28% Chorioamnionitis, 30% Multiple gestation, 30 to 50%
What serum marker is most useful for predicting preterm delivery?
Fetal fibronectin
The mechanism of action of tributylene is
Beta 2 agonist Activates adrenal cyclase ATP converted to CAMP Decreased intracellular calcium Decreased uterine contractility
What is the mechanism of action of magnesium sulfate for tocolysis?
Decreased acetylcholine released
Calcium antagonist
Decreased uterine contractility
What is a mechanism of action of indomethacin for tocolysis?
Prostaglandin synthase inhibitor
What is the mechanism of action of calcium channel blockers for tocolysis?
Inhibits transmembrane calcium and flux
Decreased uterine contractility
Miscarriage occurs in _____ percent of women less than 20 years of age and ____ percent of women greater than 40 years of age
12%
26%
Premature rupture of membranes occurs in _____ percent of all pregnancies
3-18%
PROM that occurs from 28 to 34 weeks gestation will result in
50% patients progressing to labor in 24 hours
80 to 90% progressing to labor within one week
PROM diagnosed by
pH >= 6.5
Positive ferning
Chorioamnionitis will result in neonatal sepsis for _____ percent of newborns
10%
Postterm delivery is most commonly associated with
Anencephaly
Placental sulfatase deficiency
Category B medications are defined as those
Animal studies with no fetal risks, no human studies
Adverse fetal effects in animal studies, not well controlled in human studies
Category C medications are defined as those
Inadequate animal or human studies
Adverse fetal effects in animal studies, no human studies available
Category D medications
Demonstrate fetal adverse risk but may have benefits that outweigh risks
Exam findings of a fetus exposed to ace inhibitors include
Skull hypoplasia
Fetal compression syndrome with limb deformations
Pulmonary hypoplasia
Renal tubular dysgenesis
The most common fetal tratogenic exposure is
Alcohol
Fetal alcohol syndrome is homemarked by abnormalities in
Physical exam
Growth
Neurodevelopment
The cardiac defect associated with fetal alcohol syndrome is
VSD
The anti epileptic within increased risk of hemorrhagic disease of the newborn is
Carbamazepine
Phenytoin
Phenobarbital
Presence of craniofacial defects fingernail hypoplasia growth restriction and neural tube defects in a newborn may indicate in utero exposure to
Carbamazepine
Besides still birth and placental overruption, cocaine fetal exposure may also cause
Cutis aplasia Porencephaly Illeal atresia Cardiac anomalies Visceral infarction Urinary tract abnormalities
Cyclophosphamide exposure in utero may cause
Missing digits Cleft palate Imperforate anus Microcephaly Growth restriction
Vaginal adenocarcinoma may suggest in utero exposure to
Diethylstilbestrol (DES)
Facial effects of in utero phenytoin exposure include
Cleft lip/palate
Short nose
Depressed nasal bridge
Mild hypertelorism
Major increased risks of retinoic acid during pregnancy include
Spontaneous abortions/stillbirth
Significant cardiac anomalies including transposition, truncus arteriosus, TOF
Hydrocephalus
Epstein’s anomaly is a sushi with what maternal medication?
Lithium
Methotrexate taken at _____ weeks of gestation can cause
6-8 weeks
Cranial dysplasia Broad nasal bridge Low set ears Microcephaly Craniosynostosis
Cardiac abnormalities and cleft lip and palate maybe associated with maternal medication
Phenobarbital
Premature PDA closure and pulmonary hypertension maybe associated with maternal medication
Salicylates
Phocomelia is associated with which maternal medication
Thalidomide
The maternal medication most likely to cause neural tube defects is
Valproic acid
Stippled bone epiphysis, nail hypoplasia, seizures, microcephaly, depressed nasal bridge are all contributable to which medication?
Warfarin
Warfarin administration between _______ weeks gestation is highest risk for development of fetal anomalies?
6-12, 25%
In pregnancy arsenic can cause
Spontaneous abortion
Lupus weight
Ethylene oxide, inorganic mercury, benzene, formaldehyde can cause
Spontaneous abortion
