Maternal/Fetus/Transition

Question 1

Type of twins most at-risk for twin-twin transfusion syndrome (TTTS)

Answer 1

Monochorionic–most commonly mono-di, rarely in mono-mono

By sharing chorion can have multiple placental anastamoses so blood flow can become imbalanced

Question 2

Signs (by escalating level of severity) of twin-twin transfusion syndrome (TTTS)

Answer 2

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)

Question 3

Risks to donor in twin-twin transfusion syndrome (TTTS)

Answer 3

Growth restriction

Anemia

“Stuck” (adhering to membranes 2-2 severe olighydramnios)

Death (higher risk to donor>recipient)

Question 4

Risks to recipient in twin-twin transfusion syndrome (TTTS)

Answer 4

Hypervolemia/hydrops

Polycythemia

High-output heart failure/hypertrophic cardiomyopathy

Disseminated intravascular coagulopathy and thromboembolic events

Demise (higher risk in donor)

Question 5

If one twin dies in-utero from twin-twin transfusion syndrome, the other has ____% risk of demise

Answer 5

>30%

(Often within hours; sudden shift in blood flow from pressure-drop in dead twin’s system steals from survivor–severe hypoperfusion)

Question 6

Definition of preeclampsia and severe preeclampsia

Answer 6

1. SBP>140 or DBP>90 plus proteinuria
2. SBP>160 or DBP>110 plus proteinuria

Question 7

Quad screen findings for Trisomy 21

Answer 7

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)

Question 8

What do late decelerations indicate?

Answer 8

Fetal hypoxemia

Most classic term is “uteroplacental insufficiency”

Question 9

Teratogenic effects of Isotretinoin

Answer 9

dTGA

Macrocephaly, triangular faces

_T_retinoin = _T_GA and _T_riangular _T_oo big head

Question 10

What is the most identifiable common cause of non-immune hydrops

Answer 10

Cardiac abnormalities (arryhthmias [which are often associated with CHD])

Account for 25% of non-immune hydrops

Question 11

What three organs are prioritized for oxygen delivery/blood flow

Answer 11

Adrenals

Brain

Coronaries (heart)

Question 12

Umbilical vein blood has a pO2 of ____

Answer 12

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

Question 13

How IgG transplacentally transferred

Answer 13

Pinocytosis

Really only molecule tested that’s transferred this way

Question 14

The treatments mothers with a prior infant with Neonatal Alloimmune Thrombocytopenia (NAIT) receive

Answer 14

Steroids and weekly IVIG

Start at 12 weeks if prior infant had intracranial hemorrhage (ICH) (20 weeks if no prior ICH)

Question 15

Most common cause of mild thrombocytopenia in a well-appearing newborn

Answer 15

Placental insufficiency

(Most common cause of severe thrombocytopenia is NAIT)

Question 16

What do the umbilical arteries branch off of

Answer 16

Umbilical arteries come off the internal iliac arteries

Question 17

Which ventricle provides majority of fetal cardiac output

Answer 17

Right (66% of CO)

Why it’s relatively hypertrophied at birth

Question 18

What are the PO2/oxygen saturations in the:

1) Umbilical vein
2) Left ventricle
3) Right ventricle
4) IVC/SVC

Answer 18

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)*

Question 19

The right-heart pressure is _____ the left-heart because of ________

Answer 19

1. EQUAL TO
2. Large shunts (foramen ovale and ductus arteriosus)

Question 20

In-utero, prostaglandins come from ______ and ex-utero, they’re metabolized _________

Answer 20

The placenta

In the lung vasculature

Increased PBF→faster metabolism→closure of PDA→more PBF (PBF=pulmonary blood flow)

Question 21

What two arteries constrict with increasing PaO2

Answer 21

Umbilical arteries

Ductus arteriosus

Question 22

Most heart defects occur by ___ weeks of gestation

Answer 22

8

Question 23

The earliest sign of placental insufficiency

Answer 23

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

Question 24

Maternal use of what two classes of medications could result in Potters sequence

Answer 24

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!)

Question 25

1. How long it takes for one alcoholic drink to be processed 2. When the peak concentration's in breastmilk (related to the timing of consumption)

Answer 25

1. 2 hours 2. 30-60 minutes after consumption * Alcohol IN breastmilk metabolized as well, so if mothers wait \>2h per drink before feeding/pumping, may be safe*

Question 26

Most common cause of severe thrombocytopenia in well-appearing newborns

Answer 26

Neonatal Alloimmune Thrombocytopenia (NAIT) ## Footnote *Severe is \<50 K/uL*

Question 27

What does the umbilical vein join

Answer 27

Umbilical vein joins the inferior vena cava (via the ductus venosus) ## Footnote *The portal sinus is what a UVC crosses and gets "stuck" with an acute right turn into the portal system*

Question 28

Ambiguous genitalia occur/develop by ____ weeks of gestation

Answer 28

12

Question 29

Which is NOT a neonatal sequelae of maternal diabetes: A. Stillbirth B. Neural tube defect C. Hypercalcemia D. Hypertrophic cardiomyopathy E. Hypoglycemia

Answer 29

C. Hypercalcemia ## Footnote *Hypocalcemia as a result of functional hypoparathyroidism (see hypomagnesemia in these babies as well)*

Question 30

Of the three stages of labor, only the first is subdivided--define latent and active phases of the first stage

Answer 30

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)*

Question 31

Define the second and third stages of labor

Answer 31

Second: From full cervical dilation to delivery Thid: From birth to placenta delivers

Question 32

What's defined as a prolonged latent phase of the first stage of labor

Answer 32

Nulliparous: \>20h Multiparous: \>14h

Question 33

Name teratogen associated with: Microcephaly Nasal hypoplasia with a depressed bridge Nail hypoplasia Stippled epiphyses

Answer 33

Warfarin ## Footnote * Stippled epiphyses (chondrodysplasia punctata) classic for warfarin, alcohol, hypothyroid)* (radiopaedia. org)

Question 34

Name the teratogen associated with: IUGR Digit and nail hypoplasia Umbilical and inguinal hernias

Answer 34

Phenytoin (AKA hydantoin) ## Footnote * Think IUGR and digit hypoplasia* * One of only antiepileptics (AED) where predominant defect isn't a neural tube defect (NTD)*

Question 35

What is the technical term for "flippers" and the drug associated with it

Answer 35

Phocomelia Thalidomide

Question 36

What is the main cancer treatment that's teratogenic, and its effects

Answer 36

Methotrexate Cranial dysplasia Broad nasal bridge Low-set ears

Question 37

The main teratogenic effect of valproate

Answer 37

Neural tube defects ## Footnote *Also midface hypoplasia, long philtrum, cardiac defects (especially of aorta/aortic valve) and arachnodactyly*

Question 38

What do early decelerations indicate?

Answer 38

Fetal head compression (and a vagal response)

Question 39

What are variable decelerations associated with?

Answer 39

Umbilical cord compression *Can just be a vagal response, if severe or prolonged start to worry for hypoxemia or myocardial depression*

Question 40

The average timeframe in which transient neonatal myasthenia gravis will present, and the timeframe in which 90% will resolve

Answer 40

72 hours 2 months *Hypotonia, poor feeding are most classic signs--comes from transplacental passage of anti-Ach receptor IgG*

Question 41

Fetal calcitonin is ____ in the third trimester

Answer 41

High ## Footnote *Inhibits fetal bone resorption*

Question 42

The pH of amniotic fluid

Answer 42

7 ## Footnote *Remember it's neutral whereas the vagina's normally acidic, so when checking for rupture they're testing for 6.5+*

Question 43

Immunizations contraindicated in pregnancy

Answer 43

MMR and varicella ## Footnote *Same as those that wait until children are 12+ months*

Question 44

Two diabetes medications that should be avoided in pregnancy

Answer 44

Metformin and glyburide ## Footnote *Both shown to cross the placenta*

Question 45

The HbA1c level that confers about 25% chance of congenital malformations

Answer 45

10 ## Footnote *Remember, PRE-concenption control (since teratogenic effects happen most the first 8-10 weeks) matters most*

Question 46

Gestational age for gestational diabetes screening

Answer 46

24-28 weeks ## Footnote *If glucose 140-200 requires confirmatory test; if \>200 already diagnostic*

Question 47

Which confers a greater risk to a fetus, measles or mumps?

Answer 47

Mumps ## Footnote *Both caused by paramyxovirus and acquired same way; mumps has risk of first-trimester miscarriage (only risk re: measles is preterm labor)*

Question 48

What is the highest fetal thyroid hormone

Answer 48

**Reverse** tririodothyronine (rT3) ## Footnote *Maternal T4 can cross placenta, inactivated [to rT3] by deiodinase*

Question 49

The three ways to diagnose hemolysis as part of HELLP

Answer 49

Hemolysis on smear LDH \> 600 Total bilirubin \> 1.2 *Need to demonstrate hemolysis, elevated liver enzyme (AST \>70) _and_ thrombocytopenia (\<100,000)*

Question 50

The most common fetal anomaly

Answer 50

Single umbilical artery ## Footnote *In addition to cardiac anomalies, renal anomalies it is associated with IUGR and preterm birth*

Question 51

The sensitivity of a 4-chamber *only* fetal echo vs. 4-chamber+ RVOT/LVOT views

Answer 51

60 vs. 90%

Question 52

Three things women with gestational diabetes (GDM) are at-risk for [themselves]

Answer 52

Diabetes Type 2 (\>50%) Pregancy-induced hypertension Cardiovascular disease

Question 53

How glucose crosses the placenta

Answer 53

Facilitated diffusion ## Footnote *GLUT3 most important transporter on placenta, GLUT1 on fetal tissues*

Question 54

How lipids cross the placenta

Answer 54

Simple diffusion

Question 55

How proteins (i.e. amino acids) cross the placenta

Answer 55

Active transport ## Footnote *The only energy source that needs energy spent to cross!*

Question 56

How IgG crosses the placenta

Answer 56

Pinocytosis ## Footnote *Other intact proteins also cross this way*