Fetal and neonatal Flashcards
Complications in the fetus from indomethacin in pregnancy include:
a. renal insufficiency
b. oligohydramnios
c. premature closure of the ductus arteriosus
d. all of the above
e. none of the above
d. all of the above
It’s an NSAID
Cardiovascular changes at birth
A - the most dramatic increase in individual organ blood flow after delivery is to the brain
B - gasesous expansion of the lungs is associated with a dramatic decline in pulmonary vascular resistance and decrease in pulmonary blood flow
C - foramen ovale is a flap valve that becomes functionally closed when L atrial pressure exceeds R atrial pressure
D - prostaglandins has been shown to have a minor role in the closure of the ductus arteriosus
E - with the occlusion of the umbilical cord, the large flow of blood to the placenta is interrupted causing a decrease in systemic pressure
C - foramen ovale is a flap valve that becomes functionally closed when L atrial pressure exceeds R atrial pressure
O
Occurs in the first few minutes of life
DUCTUS ARTERIOSUS - closes over course of a few hours
Pulmonary artery goes from high pressure to low pressure
Fall in prostaglandin (from placenta being removed) –> closure of ductus arteriosus
Also get constriction of smooth muscle in ductus arteriosus from high oxygen levels
What is the blood volume of a newborn baby weighing 3500gm?
A. 150 ml B. 200mL C. 250 ml D. 300 ml E. 350 ml
D. 300 ml
O
Review of numerous sources, blood volume of a term neonate is ~85mL/kg
Preterm is ~95mL/kg
An ultrasound examination reveals that your patient has a fetus with gastroschisis. You advise her that:
A - The fetus has >30% chance of an associated chromosomal abnormality
B - Surgical repair is successful in <20% of cases
C - It is uncertain whether LUSCS confers any advantages over NVD
D - The infant is likely to have severe mental retardation
C - It is uncertain whether LUSCS confers any advantages over NVD
Surgical repair is often successful Neonatal mortality low (5-10%) Increased risk of FGR and PTB Neonatal bowel complications The opening is near the umbilicus but towards to right and not directly over it - no increase in incidence of chromosomal abnormalities - only contains small bowel usually - a/w oligo
Omphalocele - membrane covered herniation, inserts into the apex of the sac (of cord insertion)
- high incidence with associated abnormalities / genetic syndromes / chromosomal abnormalities (T13, 18, Beckwidth weiderman syndrome)
- Can contain stomach, liver, spleen
- a/w poly
What is the fetal PaO2 at term?
A - 22 mmHg B - 32 mmHg C - 42 mmHg D - 52 mmHg E - 62 mmHg
B - 32 mmHg
32-35mmHg in the fetal umbilical vein
Compared to 90-100mmHg in mum
Which of the following is MOST TYPICAL of cord blood gas measurements after normal labour and vaginal delivery at term?
A. Arterial cord pH 7.27 and venous 7.34 B. Arterial cord pH 7.34 and venous 7.26 C. Arterial cord pH 7.30 and venous 7.37 D. Arterial cord pH 7.37 and venous 7.30 E. Arterial cord pH 7.37 and venous 7.34
A. Arterial cord pH 7.27 and venous 7.34
O
Median arterial pH - 7.27
Median venous pH - 7.35
Which of these crosses the placenta the least?
A - TSH
B - T4
C - TRH
D - Propylthiouracil
A - TSH
Don’t cross
- TSH
Does cross
- TRH
Which of the following drugs will affect the fetus adversely if used during pregnancy?
A - Flagyl
B - Heparin
C - Thiazide diuretics
D - Azothiaprine
C - Thiazide diuretics
Increase risk of malformations, fetal/neonatal electrolyte abnormalities, jaundice and thrombocytopenia
The most common cause of term infant mortality is:
a - congenital abnormalities b - infection c - NEC d - Bronchopulmonary dysplasia e - IVH
a - congenital abnormalities
PSANZ document - leading causes are congenital anomaly and preterm birth
*HIGH rates of SUDI as cause of infantile death but this isn’t an answer?
You see a patient with bipolar disease on Lithium 900mg /day. The risks to the fetus include:
A - CNS abnormalities
B - Cardiac abnormalities
C - Renal anomalies
D- Postmaturity
B - Cardiac abnormalities
Ebstein’s anomaly - septal and posterior leaflets of tricuspid valve are displaced towards the apex of the right ventricle –> tricuspid regurgitation –> RA dilatation
Foramen ovale doesn’t close sometimes
Rx: valve replacement and closure of the foramen ovale
Phenytoin is associated with all of the following except:
A - IUGR B - Mental retardation C - Spina bifida D - Cardiac anomalies D - Cleft palate
C - Spina bifida
"Fetal dilantin syndrome" Growth deficiency Developmental delay Characteristic facies GU abnormalities Cleft palate
A woman with bipolar affective disorder on lithium presents at 11/40. Serum lithium is 1.0 (0.9-1.4). She should be told:
a - lithium is suspected of causing heart defect
b - to cease lithium now will reduce risk to the baby
c - to reduce dose will reduce risk to baby
d - she should have CVS
e - should have amniocentesis at 16/40
a - lithium is suspected of causing heart defect
Which drug should not be used in lactation
a - Amiodarone
b - Warfarin
c - Digoxin
d - Propylthiouracil
a - Amiodarone
Secreted in high amounts in breastmilk
Contraindicated in breastfeeding
Rare cases of hypothyroidism in baby
PTU - safe 1st trimester, later in pregnancy risk of maternal liver disease, safe in breastfeeding
Warfarin - avoid in 1st trimester, 2nd and 3rd can give, safe in breastfeeding
Digoxin - minimal amounts in breastmilk, in pregnancy crosses placenta but not known to be harmful - lacking data
Which of the following is the most common cause of neonatal hyperthyroidism?
a - previous thyroidectomy on thyroxine b - Graves disease treated with PTU c - Maternal exposure to Iodine 131 during pregnancy d - Iodine deficiency goitre e - Maternal Hashimoto’s thyroiditis
b - Graves disease treated with PTU
TSH receptor stimulating antibodies (TSI)
PTU doesn’t reduce TSI
TSI can cross the placenta
Most likely cause of perinatal mortality with diabetes?
a - fetal hypoglycaemia b - congenital abnormality c - APH d - Fetal hyperinsulinaemia e - PIH
d - Fetal hyperinsulinaemia
*CHECK as M answer says B
PEDERSON HYPOTHESIS
Maternal high glucose –> fetal hyperinsulinaemia –> high rates of fetal growth and subcut fat and glycogen deposition in liver –> increased fetal metabolic rate which can provoke fetal hypoxia
Congenital abnormality - 2-4 fold increased risk
- T1DM 2.9-7.5%
- T2DM 2.1-12.3%
Management in suspected fetal hypothyroidism?
a - give mother thyroxine
b - intraamniotic thyroxine
c - do nothing in utero but give thyroxine to neonate
d - none of the above
c - do nothing in utero but give thyroxine to neonate
Usually due to TSH receptor blocking antibodies crossing the placenta
- More common in women with atrophic thyroiditis rather than Hashimoto’s
2% of congenital hypothyroidism
Refer MFM for serial USS
Of the following approaches to screening for neonatal hypothryroidism, the best one in terms of identifying the maximal number of cases is:
a - TSH only if clinically suspect hypothyroidism
b - TSH first and subsequent T4 if TSH elevated
c - Simultaneous TSH and T4 on the same specimen
d - T4 first and subsequent TSH if T4 low
c - Simultaneous TSH and T4 on the same specimen
As per RANZOCG MQCs August 2008
NB - TSH only on Guthrie card
Screening for congenital hypothyroidism
Better pick-up if combined test
Primip with no antenatal care delivers 1000 gm baby at 28/40. What is most likely cause of death?
A - sepsis
B - temp instability
C - intracranial haemorrhage
D - RDS
D - RDS
as per Lancet article
What features are suggestive of neonatal hypothyroidism – except?
a - hypotonia b - atypical facies c - open posterior fontanelle d - slow heart rate in labour e - dry skin
b - atypical facies
??
Hypotonia, dry skin - yes
Open fontanelles - yes
Puffy, coarse facial features, not necessarily atypical
Case report of fetal bradycardia but doesn’t usually happen as maternal thyroxine crosses placenta
Which one crosses the placenta
a - heparin only
b - warfarin only
c - heparin and warfarin
d - none of the above
B - warfarin only
Which one causes stipling of the epiphysis?
a - heparin only
b - warfarin only
c - heparin and warfarin
d - none of the above
b - warfarin only
stipling = pattern of focal bone calcification
- caused by warfarin, hypothyroidism, alcohol
What is the risk of congenital heart block with anti Ro + La antibodies?
A - 5%
B - 10%
C - 20%
A - 5%
Which of the congenital malformations below is MOST LIKELY to be associated with oligohydramnios?
A - VSD - isolated
B - posterior urethral valves
C - unilateral pelvic ureteric junction obstruction
D - duodenal atresia
B - posterior urethral valves
O
Keyhole sign on USS - distended bladder, oligo.
Males only affected
DA - polyhdramnios
Most likely to be associated with abnormal karyotype?
A - VSD- isolated
B - posterior urethral valves
C - PUJO – unilateral
D - duodenal atresia
D - duodenal atresia
30% of duodenal atresia with have T21
3% of those with T21 will have duodenal atresia
Vactryl association
Which of the following cannot be detected on routine US scanning?
a - hydrocephalus
b - exomphalos
c - cystic fibrosis
d - cleft palate
c - cystic fibrosis
Predominant Hb type in neonate?
a - HbA
b - HbA2
c - HbF
d - HbH
c - HbF
US (picture given) at 17/40 shows ‘frog’s eyes’ and maternal serum AFP 4 times above normal range. Following options in counselling parents?
a - defect unclear as not often seen at 17/40
b - neonatal survival is poor (<48hrs)
c - prompt termination required to avoid serious maternal complications
d - fetus will survive, but with significant morbidity
b - neonatal survival is poor (<48hrs)
frog eyes = anencephaly
What has the least effect on the fetus when given to the mother?
a - TSH
b - TRH
c - Thyroxine
a - TSH
Doesn’t cross
With respect to the fetal auditory system, which statement is correct?
a - high pitched sounds are heard best
b - depends on movement of ossicles in the air-filled middle ear
c - has completed myelination by the time of birth
d - the cochlear membrane develops from the basilar end to the apical end
d - the cochlear membrane develops from the basilar end to the apical end
Milford
*CHECK as other answer says c… Don’t think that’s correct as auditory system becomes functional at around 25/40 but don’t think it is fully myelinated until after birth.
Have found article showing development basal to apex.
Regarding AVP, which is true? (AVP = arginine vasopressin, or ADH)
a - the main determinant of fetal heart rate variability
b - causes increased fetal urine output to protect umbilical cord with amniotic fluid
c - is produced in the right atrium and right ventricle under the influence of stretch receptors
d - causes fetal tachycardia secondary to peripheral vasoconstriction
e - has increased circulating concentrations in response to haemorrhage
e - has increased circulating concentrations in response to haemorrhage
O
Made by the hypothalamus and stored in the posterior pituitary gland
Concentrates urine and preserves water
During placental development
a. a complete feto-placental circulation is developed by 5-6 weeks post conception
b. endovascular migration by
cytotrophoblasts proceeds in two episodes that are
complete by 8-10 weeks gestation
c. uteroplacental blood flow increases to 200 - 250mL/min at term
d. fetal blood flows to the placenta through paired umbilical arteries and a vein, and reaches 350 - 400mL/min average
e. approximately 55% of uterine blood perfuses the intervillous spaces, the remainder perfusing the myometrium and endometrium
a. Complete fetoplacental circulation is developed by 5-6 weeks post conception
O
Flow in cord is 110-125ml/min/kg - relatively constant in the third trimester
2 waves of endothelial cytotrophoblast invasion
- first wave at 8-10weeks
- second at 16-18weeks
Of uterine blood flow, 85% is to placenta, the rest to myometrium / endometrium / decidua
Of the fetal cardiac output,
A. half of the outflow of the right ventricle traverses the pulmonary arteries.
B. outputs of R and L ventricles are similar.
C. approximately 40% is directed to the placenta.
D. approximately one-third perfuses the brain via the carotid arteries.
E. one-half of the outflow of the right ventricle traverses the ductus arteriosus.
B. approximately 40% is directed to the placenta.
O
1/3 of combined Cardiac Output perfuses the placenta
<10% of the output of the RV reaches the lungs. Majority crosses ductus arteriosus.
40% of blood from IVC into RA crosses foramen ovale
What level of fetal Hb is associated with fetal hydrops
A - 2 B - 4 C - 6 D - 8 D - 10
B - 4
Fetal blood with the highest PO2 is in;
A - SVC as it enters the heart B - IVC as it enters the heart C - Ductus arteriosus D - Umbilical artery E - Pulmonary artery
B - IVC as it enters the heart
O
At the time of a routine prenatal assessmemt at 28weeks, the fetus of a 23year old primigravida has a heart rate of 240bpm. Echocardiogram confirms as SVT. There is evidence of pericardial effusion and moderate ascites on scan. Which is the LEAST appropriate?
a - betamethasone to the woman b - sotalol to the woman c - amiodarone to the woman d - flecanide to the woman e - delivery
e - delivery
As per RANZCOG MCQs Feb 2008
Digoxin and flecanide definitely can be used
Sotalol can also be used
Amiodarone often not used first line, but can be used
Steroids would be helpful in preparation for delivery
Male baby has just been delivered by elective LUSCS, weight 3000gm, Apgars 7(1), 9(5). After a couple of hours he develops grunting and intercostal recession and RR 80 which is all better by 18 hrs. Mechanism?
A - surfactant deficiency
B - delayed resorption of lung liquid
C - acidosis
D - neonatal pneumonia
B - delayed resorption of lung liquid
Assuming term
All are causes of haemolytic disease of newborn except:
A - Kell
B - Duffy
C - Lewis
D - ABO
C - Lewis
Which ultrasound features are the least accurate assessment of gestational age?
A - BPD
B - FL
C - AC
D - BPD/FL ratio
C - AC
M
As most affected by growth conditions e.g IUGR and liver size from mobilisation of glycogen stores vs macrosomia
The expected weight of a 28 week fetus to deliver is:
A - 600 gms B - 800 gms C - 1100 gms D - 1300 gms E - 1600 gms
C - 1100 gms
Milford
- as long as no adverse factors
Streaming of blood in the fetal IVC result in:
a - more oxygenated blood being directed through the foramen ovale to the left atrium
b - deoxygenated blood from the coronary sinuses being directed to the aorta
c - deoxygenated blood being directed to the left lobe of the liver
d - oxygenated blood travelling in the right ventral portion of the IVC
a - more oxygenated blood being directed through the foramen ovale to the left atrium
The fetal kidney:
a - is just as responsive to aldosterone as the adult kidney
b - produces hyperosmolar urine
c - responds to hyperosmolar mannitol by increasing GFR to excrete the osmotic load
c - responds to hyperosmolar mannitol by increasing GFR to excrete the osmotic load
Can’t concentrate urine until the first year of life
- therefore yellow urine in newborn is abnormal –> easy to diagnose jaundice
Hyperosmolar urine = concentration urine
Fetal adrenal produces very little aldosterone
