Maternal/Fetus/Transition Flashcards
Type of twins most at-risk for twin-twin transfusion syndrome (TTTS)
Monochorionic–most commonly mono-di, rarely in mono-mono
By sharing chorion can have multiple placental anastamoses so blood flow can become imbalanced
Signs (by escalating level of severity) of twin-twin transfusion syndrome (TTTS)
I: poly/oligo-hydramnios
II: absent bladder (donor)–this and anything more warrants laser occlusion/ablation
III: abnormal doppler flows (signifying insufficient delivery to donor)
IV: hydrops (recipient)
V: demise
(Quintero staging)
Risks to donor in twin-twin transfusion syndrome (TTTS)
Growth restriction
Anemia
“Stuck” (adhering to membranes 2-2 severe olighydramnios)
Death (higher risk to donor>recipient)
Risks to recipient in twin-twin transfusion syndrome (TTTS)
Hypervolemia/hydrops
Polycythemia
High-output heart failure/hypertrophic cardiomyopathy
Disseminated intravascular coagulopathy and thromboembolic events
Demise (higher risk in donor)
If one twin dies in-utero from twin-twin transfusion syndrome, the other has ____% risk of demise
>30%
(Often within hours; sudden shift in blood flow from pressure-drop in dead twin’s system steals from survivor–severe hypoperfusion)
Definition of preeclampsia and severe preeclampsia
- SBP>140 or DBP>90 plus proteinuria
- SBP>160 or DBP>110 plus proteinuria
Quad screen findings for Trisomy 21
Low AFP, high bHCG, low estradiol, high inhibin
Put in alphabetical order and then alternates low-high-low-high (remember it “starts” with low because only open defects cause high AFP)
What do late decelerations indicate?
Fetal hypoxemia
Most classic term is “uteroplacental insufficiency”
Teratogenic effects of Isotretinoin
dTGA
Macrocephaly, triangular faces
_T_retinoin = _T_GA and _T_riangular _T_oo big head
What is the most identifiable common cause of non-immune hydrops
Cardiac abnormalities (arryhthmias [which are often associated with CHD])
Account for 25% of non-immune hydrops
What three organs are prioritized for oxygen delivery/blood flow
Adrenals
Brain
Coronaries (heart)
Umbilical vein blood has a pO2 of ____
30mmHg (half the lower-limit of normal ex-utero)
About 1/3 of this oxygenated blood bypasses to the aorta through the foramen ovale (since it’s ejected pre-DA, it goes to most oxygen-needy coronaries and head)
A THIRD of this THIRTY mmHg blood goes to the THIRSTY heart and brain
How IgG transplacentally transferred
Pinocytosis
Really only molecule tested that’s transferred this way
The treatments mothers with a prior infant with Neonatal Alloimmune Thrombocytopenia (NAIT) receive
Steroids and weekly IVIG
Start at 12 weeks if prior infant had intracranial hemorrhage (ICH) (20 weeks if no prior ICH)
Most common cause of mild thrombocytopenia in a well-appearing newborn
Placental insufficiency
(Most common cause of severe thrombocytopenia is NAIT)
What do the umbilical arteries branch off of
Umbilical arteries come off the internal iliac arteries
Which ventricle provides majority of fetal cardiac output
Right (66% of CO)
Why it’s relatively hypertrophied at birth
What are the PO2/oxygen saturations in the:
1) Umbilical vein
2) Left ventricle
3) Right ventricle
4) IVC/SVC
1) UV: PO2 40 / SaO2 80% (DV SaO2 70% per Brodsky)
2) LV: PO2 30 / SaO2 65%
3) RV: SaO2 55%
4) SVC/IVC: PO2 15 / SaO2 30%
* (Some variation in quoted numbers in literature, these picked as representative and easy to remember)*
The right-heart pressure is _____ the left-heart because of ________
- EQUAL TO
- Large shunts (foramen ovale and ductus arteriosus)
In-utero, prostaglandins come from ______ and ex-utero, they’re metabolized _________
The placenta
In the lung vasculature
Increased PBF→faster metabolism→closure of PDA→more PBF (PBF=pulmonary blood flow)
What two arteries constrict with increasing PaO2
Umbilical arteries
Ductus arteriosus
Most heart defects occur by ___ weeks of gestation
8
The earliest sign of placental insufficiency
Small abdominal circumference 2-2 decreased liver size
Decreased placental flow/O2→dilated ductus venosus to “spare” brain→decreased portal sinus shunting→smaller abd organs
Maternal use of what two classes of medications could result in Potters sequence
ACEI and ARBs (angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers)
Primary driver of nephrogenesis is renin-angiotensin system (reason to not use these in babies PMA<36 weeks when nephrogenesis is still happening!)
- How long it takes for one alcoholic drink to be processed
- When the peak concentration’s in breastmilk (related to the timing of consumption)
- 2 hours
- 30-60 minutes after consumption
* Alcohol IN breastmilk metabolized as well, so if mothers wait >2h per drink before feeding/pumping, may be safe*
Most common cause of severe thrombocytopenia in well-appearing newborns
Neonatal Alloimmune Thrombocytopenia (NAIT)
Severe is <50 K/uL
What does the umbilical vein join
Umbilical vein joins the inferior vena cava (via the ductus venosus)
The portal sinus is what a UVC crosses and gets “stuck” with an acute right turn into the portal system
Ambiguous genitalia occur/develop by ____ weeks of gestation
12
Which is NOT a neonatal sequelae of maternal diabetes:
A. Stillbirth
B. Neural tube defect
C. Hypercalcemia
D. Hypertrophic cardiomyopathy
E. Hypoglycemia
C. Hypercalcemia
Hypocalcemia as a result of functional hypoparathyroidism (see hypomagnesemia in these babies as well)
Of the three stages of labor, only the first is subdivided–define latent and active phases of the first stage
Latent: Starts when uterine contractions AND cervix changes slowly (ends when dilation speeds up, which varies).
Active: Rate of cervix dilation more rapid (≥1cm/h), for most starts between 3-6cm. Ends when fully dilated.
(Classic Friedman definition was active phase started at 3cm but newer data suggests may be later)
Define the second and third stages of labor
Second: From full cervical dilation to delivery
Thid: From birth to placenta delivers
What’s defined as a prolonged latent phase of the first stage of labor
Nulliparous: >20h
Multiparous: >14h
Name teratogen associated with:
Microcephaly
Nasal hypoplasia with a depressed bridge
Nail hypoplasia
Stippled epiphyses
Warfarin
- Stippled epiphyses (chondrodysplasia punctata) classic for warfarin, alcohol, hypothyroid)*
(radiopaedia. org)
Name the teratogen associated with:
IUGR
Digit and nail hypoplasia
Umbilical and inguinal hernias
Phenytoin (AKA hydantoin)
- Think IUGR and digit hypoplasia*
- One of only antiepileptics (AED) where predominant defect isn’t a neural tube defect (NTD)*
What is the technical term for “flippers” and the drug associated with it
Phocomelia
Thalidomide
What is the main cancer treatment that’s teratogenic, and its effects
Methotrexate
Cranial dysplasia
Broad nasal bridge
Low-set ears
The main teratogenic effect of valproate
Neural tube defects
Also midface hypoplasia, long philtrum, cardiac defects (especially of aorta/aortic valve) and arachnodactyly
What do early decelerations indicate?
Fetal head compression (and a vagal response)
What are variable decelerations associated with?
Umbilical cord compression
Can just be a vagal response, if severe or prolonged start to worry for hypoxemia or myocardial depression
The average timeframe in which transient neonatal myasthenia gravis will present, and the timeframe in which 90% will resolve
72 hours
2 months
Hypotonia, poor feeding are most classic signs–comes from transplacental passage of anti-Ach receptor IgG
Fetal calcitonin is ____ in the third trimester
High
Inhibits fetal bone resorption
The pH of amniotic fluid
7
Remember it’s neutral whereas the vagina’s normally acidic, so when checking for rupture they’re testing for 6.5+
Immunizations contraindicated in pregnancy
MMR and varicella
Same as those that wait until children are 12+ months
Two diabetes medications that should be avoided in pregnancy
Metformin and glyburide
Both shown to cross the placenta
The HbA1c level that confers about 25% chance of congenital malformations
10
Remember, PRE-concenption control (since teratogenic effects happen most the first 8-10 weeks) matters most
Gestational age for gestational diabetes screening
24-28 weeks
If glucose 140-200 requires confirmatory test; if >200 already diagnostic
Which confers a greater risk to a fetus, measles or mumps?
Mumps
Both caused by paramyxovirus and acquired same way; mumps has risk of first-trimester miscarriage (only risk re: measles is preterm labor)
What is the highest fetal thyroid hormone
Reverse tririodothyronine (rT3)
Maternal T4 can cross placenta, inactivated [to rT3] by deiodinase
The three ways to diagnose hemolysis as part of HELLP
Hemolysis on smear
LDH > 600
Total bilirubin > 1.2
Need to demonstrate hemolysis, elevated liver enzyme (AST >70) and thrombocytopenia (<100,000)
The most common fetal anomaly
Single umbilical artery
In addition to cardiac anomalies, renal anomalies it is associated with IUGR and preterm birth
The sensitivity of a 4-chamber only fetal echo vs. 4-chamber+ RVOT/LVOT views
60 vs. 90%
Three things women with gestational diabetes (GDM) are at-risk for [themselves]
Diabetes Type 2 (>50%)
Pregancy-induced hypertension
Cardiovascular disease
How glucose crosses the placenta
Facilitated diffusion
GLUT3 most important transporter on placenta, GLUT1 on fetal tissues
How lipids cross the placenta
Simple diffusion
How proteins (i.e. amino acids) cross the placenta
Active transport
The only energy source that needs energy spent to cross!
How IgG crosses the placenta
Pinocytosis
Other intact proteins also cross this way
