Fetal and neonatal Flashcards by Edward Lim (2024)

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 mlB. 200mLC. 250 mlD. 300 mlE. 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 PTBNeonatal bowel complicationsThe 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 mmHgB - 32 mmHgC - 42 mmHgD - 52 mmHgE - 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 vagin*l delivery at term?

A. Arterial cord pH 7.27 and venous 7.34B. Arterial cord pH 7.34 and venous 7.26C. Arterial cord pH 7.30 and venous 7.37D. Arterial cord pH 7.37 and venous 7.30E. 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 abnormalitiesb - infectionc - NECd - Bronchopulmonary dysplasiae - 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 deficiencyDevelopmental delayCharacteristic faciesGU 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

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 thyroxineb - Graves disease treated with PTUc - Maternal exposure to Iodine 131 during pregnancyd - Iodine deficiency goitree - 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 hypoglycaemiab - congenital abnormalityc - APHd - Fetal hyperinsulinaemiae - 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 - hypotoniab - atypical faciesc - open posterior fontanelled - slow heart rate in laboure - 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

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%

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

Predominant Hb type in neonate?

a - HbA
b - HbA2
c - HbF
d - HbH

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 - 2B - 4C - 6D - 8D - 10

Fetal blood with the highest PO2 is in;

A - SVC as it enters the heartB - IVC as it enters the heartC - Ductus arteriosusD - Umbilical arteryE - 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 womanb - sotalol to the womanc - amiodarone to the womand - flecanide to the womane - 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

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 gmsB - 800 gmsC - 1100 gmsD - 1300 gmsE - 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

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

Fetal lungs:

A - are 80% of the volume that they will be immediately after birth
B - lung movement is required for the production of surfactant
C - the pressure in the trachea is less than that in amniotic fluid
D - none of the above

D - none of the above

Lung movement isn’t required for surfactant production
Pressure in trachea will be equal to that in the amniotic fluid

Uncertain about A

Fetal urine amount related to?

A - fetal weight
B - gestational age

A - fetal weight

Can calculate neonatal expected UO based on weight

Which is not produced by the fetus?

A - oestrogen
B - insulin
C - ACTH
D - TSH

A - oestrogen

Made by mum and placenta

ACTH - detected from 12/40
Make insulin by 20/40
Thyroid function starts ~20/40, under influence of fetal TSH

What contributes most to AFI in late gestation?

A - fetal swallowing
B - fetal urination
C - transudation across membranes

B - fetal urination

Milford

Regarding cerebral palsy and birth asphyxia

A - 50% of affected infants will have apgars less than 3 at 5 minutes
B - most affected infants will have normal apgars
C - early neonatal fitting does not indicate a poor prognosis

B - most affected infants will have normal apgars

is the pathogenesis for CP due to birth asphyxia
CRITERIA FOR HIE:
0-3 for >5 mins
Significant hypoxic event before or during labour and delivery
Profound acidaemia (pH <7 of umbilical cord artery)
Neonatal neuro manifestations - seizures, hypotonia, coma
Multisystem organ dysfunction

Only 10% of CP in term or near term infants is due to birth asphyxia
- Usually spastic quadraplegia or dyskinetic CP

An elective CS was performed at 38/40 for grade 4 placenta praevia under GA. Infant was delivered with Apgars of 9 and 9. The infant develops increasing respiratory effort 1 hr after birth. What is the most likely diagnosis?

A - hyaline membrane diseaseB - pneumonitisC - transient tachypnoea of newbornD - prolonged effects of newbornE - birth asphyxia

C - transient tachypnoea of newborn

TTN and NICU at ElCS
37weeks 7-11%
38weeks 6%
39weeks 1.5%

Baby’s born < 32 weeks are most likely to die from?

A - HMD (hyaline membrane disease)
B - NEC
C - Subdural haemorrhage
D - Infection

Which is the most likely chromosomal abnormality in 3rd trimester FDIU (fetal death in utero)?

A - T21b - T18c - T13d - Triploidye - Turners syndrome

US at 28/40 shows ventriculomegaly with a cortical mantle thickness of 8mm. You advise:

A - prognosis bleak – TOP advised
B - prognosis is uncertain and await spontaneous labour
C - ventriculocentesis will causes brain damage
D - could be prevented by preconceptual folate

C - ventriculocentesis will causes brain damage

Up to date says that it is nearly always fatal

Rarely, used to decompress the fetal head to allow vagin*l delivery to reduce maternal morbidity

Suggest to use where neurological prognosis is so bad that is the baby dies it doesn’t make a difference

*CHECK as M answer says B?

A term infant has just been delivered with Apgar 1 at 1. Airway cleared. Next most appropriate step?

a - IM Konakion
b - Intraumbilical glucose and bicarb
c - Continue to bag and mask
d - Intubate

Shoulder dystocia – most likely injury?

a - Nerve
b - fractured clavicle
c - fractured humerus

a - Nerve

Transient nerve injury up to 16%
Permanent nerve injury 1%
# clavicle (up to 9.5%) - double rate of humeral # (up to 4.2%)

HIE 0.3%
Death 0.35%
PPH 11%
3rd or 4th degree - 4%

Advantages of rooming in: all except?

a - baby gets colonised with mum’s bugs, not othersb - decreased SIDS laterc - facilitates 4 hrly feedsd - increase uterine involutione - improves let down

a - baby gets colonised with mum’s bugs, not others

*CHECK as M answer says C as facilitates on demand feeds not regimented

Para 3, all SVD at term weighing > 3600gm. Now 36 weeks gestation with a 31 cm fundus. US BPD = 7.9 cm, BPP normal. Management?

a - delivery by CSb - karyotype the fetusc - biweekly US to assess fetal growthd - amniocentesis for L:S ratioe - reassure and change the EDD

b - karyotype the fetus

M

*CHECK as other answer says C
Justification for doing karyotype as with no Hx of IUGR there is are a higher chance this is attributed to aneuploidy

Regarding placental sulfatase deficiency, which statement is correct?

A- premature labour is a feature
B - equal sex distribution with fetal effects
C - inheritance is X-linked recessive
D - associated with neonatal dermatitis

C - inheritance is X-linked recessive

Results in lack of cervical dilatation
High rates of post dates and CS
Leads to icythosis in affected males

In the newborn infant, normal circulation changes associated with neonatal life include all EXCEPT

a. Increase pulmonary venous flow
b. Increase in left atrial pressure
c. Increase in pulmonary venous resistance
d. Increase in renal blood flow
e. Decrease in ductus venosus flow

c.Increase in pulmonary venous resistance

O

The blood volume of a 3.5kg infant at term is approximately

a. 200mL
b. 250mL
c. 300mL
d. 350mL

c.300mL

85ml/kg

You are called to Delivery Suite to attend a recently delivered baby with ambiguous genitalia. You cannot assign a gender to the baby. After 24 hours, your NEXT step should be;

a. Order immediate serum electrolytes
b. Order serum 17-OH progesterone levels
c. Arrange for serum testosterone and 17-oxosteroids the following day
d. Order an USS to check for presence/absence of uterus or testicl*s
e. Organise blood to be taken for chromosome analysis the next day

b.Order serum 17-OH progesterone levels

O

Salt wasting crisis can take days to establish
Congenital adrenal hyperplasia
Most common cause of ambiguous genitalia
Levels will be very high as 21 alpha hydroxylase enzyme deficient so cannot convert 17-OH to 11-deoxycortisol

Wait 24h to allow 17-OH progesterone produced by the placenta to disappear

17-oxosteroids - metabolite found in urine - confirms 11 b hydroxylase deficiency

Which is LEAST CORRECT regarding cerebral palsy

a. Around 5% of those with Apgar < 4 at 10 minutes will develop CP
b. Around 25% of babies with grade 3 HIE will develop CP
c. Around 50/1000 surviving triplets will develop CP
d. Around 10/1000 surviving twins will develop CP

b.Around 25% of babies with grade 3 HIE will develop CP

O

2 cases per 1000 live births - live births

HIE grade 3
- High mortality (75%) and neurologic disability (80% of survivors)

A 4 day old neonate suddenly becomes unwell, dehydrated and hypotensive. There is cl*toromegaly with rugosity of the labia. She is hyponatraemic, hyperkalaemic, urea 8.0mmol. What is the most likely additional laboratory finding?

a. Karyotype XY
b. Elevated Testosterone
c. Markedly elevated 17OH progesterone (200)
d. Markedly elevated blood glucose level

c.Markedly elevated 17OH progesterone

O

Salt wasting crisis of CAH

Will be 46XX - karyotype not affected with CAH
Expect testosterone to be much higher
BSL low

Normal 17OH progesterone <4

In a full term neonate with omphalocele, which factor is MOST important to determine prognosis

a. Size of the defect
b. Presence of other anomalies
c. Mode of delivery
d. Method of surgical repair

b.Presence of other anomalies

O

Which best describes the relationship between Apgar scores and neurologic outcomes?

a. A 10 minute apgar of 0-3 and neonatal convulsions is not predictive of poor neurological outcome
b. 75% of children with Cerebral palsy had normal Apgar scores
c. 1/3 of infants with a 5 minute score 0-3 will have poor long term neurological outcomes
d. The 1 minute score correlates well with long term neurological outcomes

b.75% of children with Cerebral palsy had normal Apgar scores

O

A full term infant has an Apgar score of 2 at 1 minute. The MOST appropriate statement is

a. The infant will develop seizures
b. The infant needs immediate transfer to Special Care
c. The infant has significant hypoxia
d. The infant needs resuscitation

d.The infant needs resuscitation

O

A 4 day old neonate weighing 3800g develops vagin*l bleeding. You should:

a. Test for haemoglobin in the next stool specimen
b. Reassure the family
c. Arrange EUA to exclude vagin*l tumour
d. Arrange pelvic ultrasound to exclude uterine tumour
e. Suprapubic bladder puncture to check for UTI

b.Reassure the family

O

A woman has a 46XX child born with Congenital Adrenal Hyperplasia and virilisation requiring surgical correction and steroid therapy. In the next pregnancy you would recommend:

a. Commence dexamethasone at the diagnosis of pregnancy
b. Commence prednisolone at the diagnosis of pregnancy
c. Amniocentesis to diagnose fetal sex and commence dexamethasone if female
d. Amniocentesis to diagnose fetal sex and commence prednisolone if female

a.Commence dexamethasone at the diagnosis of pregnancy

If fetus at risk of CAH, treat with dexamethasone 20mcg/kg daily to avoid virilisation of an affected female ideally <5/40

• Suppresses fetal ACTH and reduce fetal adrenal hyperandrogenism
• Continue until sex determined and paternal status is known
• If female and partner carrier –> CVS
• If fetus affected, continue dexamethasone or offer TOP

Which statement about neonatal circulatory changes at birth is CORRECT

a. Gaseous expansion of the lungs causes an increase in pulmonary vascular resistance and increase in pulmonary blood flow
b. Pulmonary venous return doubles
c. Prostaglandin E1 causes closure of the Ductus Arteriosus
d. Ductus venosus oxygen tension falls
e. When the umbilical cord is occluded, the flow of blood to the placenta is interrupted, causing a decrease in systemic blood pressure

d.Ductus venosus oxygen tension falls

Correct as per RANZCOG 2010 MCQs

NB A is incorrect as there is a FALL in pulmonary vascular resistance at birth

Neonatal hyperthyroidism is most likely to be caused associated with

a. Maternal Graves disease controlled by previous surgery
b. Untreated maternal toxic thyroid adenoma
c. DiGeorge syndrome
d. Carbimazole therapy

a.Maternal Graves disease controlled by previous surgery

As per RANZCOG MCQs Feb 2010

Will still have TRAbs which may cross placenta and affect fetus.
Need to still test in pregnancy, TrAB >40 puts fetus/neonate at much higher risk

Which of the following is the KEY mode of current therapy for fetal alloimmune Thrombocytopenia?

A. Maternal immunoglobulin infusion
B. In-utero fetal platelet transfusion
C. Corticosteroid therapy with prednisolone
D. Plasmapheresis

33yo multiparous woman at 18 weeks gestation is being treated with lithium for bipolar disorder. Which of the following ultrasound findings is most likely to be associated with use of this medication in pregnancy?

a) Spina Bifida
b) Dysplastic kidney
c) Cleft lip
d) Cardiac defect
e) Coarctation of the aorta

d) Cardiac defect

Ebstein’s anomaly

A mother asks you to review her 3 day old male baby who has a swollen left breast with a discharge. She is very distressed. The best initial response is to:

a) Organise an urgent surgical referral
b) Refer her to the team neonatalogist
c) Reassure her its physiological
d) Refer her to the mother and baby unit

c) Reassure her its physiological

O

Can be unliateral.
Probably should still refer to neonatal as not our specialty area? Ddx to include mastitis of the engorged neonatal breast.

You perform a forceps delivery for foetal distress. On routine newborn examination of the male’s baby, a “clicky hip” is noted. The mother is worried as none of her 3 previous children had this problem. In response to her questions about congenital dislocation of the hip, you inform her that:

a) It is more common in boys than in girls
b) It is more common in children with an affected first degree relative
c) It is more common in babies delivered by forceps
d) It is more common in women who carry their baby on their hip with legs abducted

b) It is more common in children with an affected first degree relative

O

Risk factors:
Girls, firstborn, breech in utero, affected first degree relative

Thyroid hormone

A. must be present for the fetus to grow.
B. has increased circulating levels after birth in preterm, but not term infants.
C. is active in the fetus in the form of reverse T3.
D. is necessary for shivering, but not non-shivering thermogenesis.
E. has increased levels after birth because of a surge in TSH levels.

E. has increased levels after birth because of a surge in TSH levels.

O

Serum TSH concentrations rise abruptly A/w exposure to cold Initial surge in TSH --> stimulates T4 secretionT4 peaks 24-36h of lifeSerum T3 also rises at same time

Serum TSH levels rise rapidly in the first minutes after birth and peak at 30 minutes of postnatal life

In the newborn infant, normal circulatory changes associated with neonatal life include an increase in all of the following EXCEPT:

A. the flow in the pulmonary veins.
B. the left atrial pressure.
C. pulmonary vascular resistance.
D. renal blood flow.

Which of the following IS FALSE regarding
the use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in pregnancy?

A. Oligohydramnios is a side effect of selective COX-2 antagonists
B. Premature closure of the ductus arteriosus is less likely at an advanced gestational age than extremely premature gestations
C. Nimesulide is a COX-2 antagonist but has still been associated with oligohydramnios, renal arterial vasoconstriction and neonatal renal impairment
D. Sulindac has reduced concentration of the active metabolite in the fetal circulation but has been associated with premature closure of the ductus arteriosus and oligohydramnios

B. Premature closure of the ductus arteriosus is less likely at an advanced gestational age than extremely premature gestations.

O

Infants closer term are more susceptible to this - explains why NSAIDs contraindicated in 3rd trim but in certain circ*mstances okay up to 28-30weeks.

Oligo is side effect of ALL COX inhibitors (but less so in low dose aspirin owing to low dose being more selective for thromboxane inhibition - explains predominant protection for early PET, IUGR).

Of the following antibodies, which is the predominant type produced by the fetus?

a. IgA
b. IgM
c. IgE
d. IgG

b. IgM

Developed during fetal development from 20/40

At the time of a routine antenatal examination at 28 weeks gestation, the fetus of a 23-year-old woman G1P0 has a fetal heart rate of 240 bpm. Echocardiography confirms a supraventricular tachyarrhythmia. The fetus has a small pericardial effusion and a moderate amount of ascites.
Which of the following would be most appropriate?

a. Administration of Verapamil to the woman
b. Administration of Sotalol to the woman
c. Administration of Labetalol to the woman
d. Administration of Amiodarone to the woman

b. Administration of Sotalol to the woman

For fetal arrhythmias

1st line is flecanide
2nd line is sotalol
3rd digoxin
4th line is amiodarone

Which of the following is most typical of a fetal scalp pO2 measured in early labour?

a. 22 mmHg
b. 32 mmHg
c. 42 mmHg
d. 52 mmHg

a. 22 mmHg

O

Fetal scalp pO2 normal 20-30mmHg

Normal adult venous O2 approx 30-40mmHg
- 80-100mmHg for arterial

In developed countries fetal hypothyroidism is most likely to result when the mother has:

a. Graves’ disease treated with thyroidectomy
b. autoimmune thyroiditis.
c. carbamazepine overdose.
d. iodine deficiency.

b. autoimmune thyroiditis.

in the developing world - it is iodine deficiency

Which of the following statements is FALSE?

A. An increase in the “anion gap” (non-chloride, non-bicarbonate anions) is commonly seen in diabetic ketoacidosis.
B. The oxygen-haemoglobin dissociation curve in the fetus is shifted to the right when compared to the adult.
C. After bicarbonate, haemoglobin is the next most important acid-base buffer for the fetus.
D. Base deficit is defined as the bicarbonate ion concentration below normal

B. The oxygen-haemoglobin dissociation curve in the fetus is shifted to the right when compared to the adult.

O

Shifts to the L

The Guthrie test for phenylketonuria is:

a. exclusion testing.
b. predictive testing.
c. carrier testing.
d. diagnostic testing.

d. diagnostic testing.

O

GUTHRIE CARD CONDITIONSCystic fibrosisPKUCongenital hypothyroidismCongenital adrenal hyperplasiaMaple syrup urine diseaseFatty acid oxidation disorders (e.g. MCAD)GalactosaemiaSevere combined immunodeficiency (SCID)Biotinidase deficiency

In the human fetus, behavioural state 2F is characterised by

a. Breathing and eye movements with frequent accelerations of the heart rate
b. Absent eye and breathing movements with minimal variability of the heart rate
c. Infrequent body movements but continued breathing and eye movements
d. Occurring most of the time by term gestation
e. High voltage, slow wave EEG patterns

a. Breathing and eye movements with frequent accelerations of the heart rate

O

• like REM sleep

1F - quiet sleep
2F - active sleep
4 - active, awake activity

Amnio revealed 46 XY but baby born with female external genitalia.
What is the most likely cause?

a. Lab error
b. Androgen insensitivity syndrome
c. Mullerian agenesis

b. Androgen insensitivity syndrome

M

How many weeks post conception does NT close?

a. 4
b. 6
c. 8
d. 10
e. 12

a. 4

Closure occurs between day 26 - cranial and 28 - caudal post-conception

The “D” antigen first appears on RBCs at

a. 5w
b. 8w
c. 12w
d. 16w
e. 22w

a. 5w

According to UTD the D antigen is expressed by 30 days gestation.

M

What is the average weight of the term placenta?

a. 100g
b. 450g
c. 720g
d. 1000g
e. 1200g

b. 450g

M

Meningomyelocoele is associated with:

a. Trisomy 21
b. Turner’s syndrome
c. Trisomy 18
d. Arnold Chiari malformation
e. Noonan syndrome

d. Arnold Chiari malformation

M

A 3cm unilateral choroid plexus cyst was found on routine antenatal US at 24 weeks. Which of the following is correct?

a. Reassure mother and no follow up required
b. Perform serial US and reassure mother is cyst remains the same
c. Cephalocentesis is indicated
d. Choroid plexus cyst is most commonly found in 3rd ventricle
e. Perform an amniocentesis to obtain fetal karyotype

a. Reassure mother and no follow up required

Choroid plexus cysts are a common finding (0.18-3.6%) with an association with trisomy 18 and other chromosomal abnormalities. It occurs in the lateral ventricles growing in the first trimester and have usually disappeared by the third trimester.

M

What is this syndrome – choroid plexus cysts, cystic hygroma, absent 3rd and 4th digits?

a. CMV
b. Rubella
c. T21
d. T18
e. T13
f. Turners syndrome

F. Turners syndrome

M

Microcephaly, flat nose, thin upper lip, large distance between nose and lip. Which drug is culprit?

a. ETOH
b. Marijuana
c. Cocaine
d. Amphetamines
e. Heroin

a. ETOH

M

A woman developed increasing pressure symptoms at 30 weeks. Known to have an O+ve blood group. On examination, fundus 35cm, fetal parts difficult to identify. The CTG has a baseline FHR of 200 bpm with no evidence of decelerations. No clinical evidence of chorioamnionitis. USS showed fetal pleural and pericardial effusions.
What is your next step in management?

a. Fetal pericardiocentesis
b. Commence on oral digoxin
c. Amniocentesis for fetal karyotype
d. Delivery
e. Observe and repeat US 2w.

b. Commence on oral digoxin

The clinical picture is consistent with hydrops fetalis. The likely cause of the hydrops is a fetal tachyarrhythmia given that the FH is 200. The management of this would maternal administration of digoxin.

M

*NB similar Q higher up

All of the following occur in congenital rubella except:

a. Cataracts
b. Deafness
c. IUGR
d. Cardiac defects
e. Renal dysplasia

e. Renal dysplasia

M

Steroids in a preterm baby will

a. Reduce RDS
b. Reduce IVH
c. Reduce NEC
d. All of the above
e. A and B but not C

d. All of the above

M

Which of the following is NOT true?

a. The perinatal mortality rate in singletons is roughly 8/1000
b. The perinatal mortality rate of twins is roughly 40/1000
c. The perinatal mortality rate of triplets is roughly 70/1000
d. The rate of cerebral palsy in singletons is roughly 2/1000
e. The rate of cerebral palsy of twins is roughly 10/1000
F. The rate of cerebral palsy of triplets is roughly 50/1000

c. The perinatal mortality rate of triplets is roughly 70/1000

O

A woman is 22 weeks pregnant with DCDA twins. She had a normal morphology USS at 20weeks.
Death of twin A is confirmed at 22 weeks. She proceeds to have a SVB at term. Which of the following is correct?

a. Register the birth of the live twin, the dead twin does not need to be registered
b. Register the birth of both twins
c. Register as a singleton pregnancy

b. Register the birth of both twins

E agrees

As per Di Leishman’s recent session gestation definition counts “as it is birthed by the mother”

A woman is 32 weeks pregnant. She has previously had a thyroidectomy for Graves disease and takes thyroxine. She has an USS which show the fetus to be hyperthyroid, with fetal tachycardia.
What would you do with the mother’s thyroid dose?

a. Cease the thyroxine
b. Lower the dose
c. Keep at the same dose
d. Keep at the same dose and give carbimazole

d. Keep at the same dose and give carbimazole

E agrees

TRAbs >40 put fetus/neonate at highest risk
Overall 1% risk of neonatal hyperthyroidism
Treatment is maternal to enable placental passage
If left untreated risk of progression to hydrops, 25% mortality.

Randomised controlled trials have shown that maternal indomethacin therapy is significantly associated in the fetus with:

A. renal insufficiency.
B. constriction of the ductus arteriosus.
C. necrotising enterocolitis.
D. deafness.

B best answer?

*Unable to find an RCT which looks at this outcome. Meta-analyses actually say NEC.
UTD says B is main effect

A woman delivers a 3kg baby at term with ambiguous genitalia. The karyotype is 46XX and the 17-OHP is 100 (N is <20). The baby undergoes surgical correction of its genital abnormalities successfully and is commenced on steroid replacement therapy.
In her next pregnancy you would recommend

A. commencement of dexamethasone at pregnancy diagnosis
B. commencement of prednisolone at pregnancy diagnosis
C. amniocentesis to diagnose fetal sex and commence dexamethasone if fetus is female
D. amniocentesis to diagnose fetal sex and commence prednisolone if fetus is female

A. commencement of dexamethasone at pregnancy diagnosis

O

Need to start before week 6
Critical fetal genitalia development at 7-12weeks
Risk of unnecessary high dose steroid exposure if baby turns out to be a male

At what week post-conception does the neural tube close?

A) 2 weeks
B) 4 weeks
C) 6 weeks
D) 8 weeks

B) 4 weeks

By day 26

Streaming of blood in the fetal IVC results 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

Endothelial growth factor

A) Was first isolated from frog skin
B) Reaches high levels in the fetal circulation
C) Causes respiratory distress by inducing epithelial overgrowth in neonatal lungs
D) In high doses, induces excessive growth of hair or wool
E) Its receptors are stimulated by TGF-alpha

After a normal pregnancy, an infant is born with ambiguous genitalia.
Which is the MOST URGENT of the following investiagtions?

A. Karyotype
B. Serum electrolytes
C. Serum 17-OHP
D. Y-chromosome fluoresecence studies

B. Serum electrolytes

O

NB discrepancy in RANZCOG answers - similar Q says 17-OHP after 24hours but this Q is not specifically after 24hours.

When does fetal thyroid hormone begin to be produced?

A. 8 weeks
B. 12 weeks
C. 18 weeks
D. 24weeks

B. 12 weeks

Still dependent on maternal iodine after this point