Ch 9 - Perinatal medicine

Question 1

Pre-pregnancy care - couples often ask what they should do for optimum care: lifestyle (2), Supplement (1), Medication termination (3), Infectious diseases (3), Vitamin A (1)

Answer 1

Lifestyle - Smoking cessation also alc & drugs lol
Supplement - Folic acid; prevents neural tube defects
Medications - certain meds need to be stopped e.g. warfarin, retinoids, sodium valproate - becasue they are teratogenic
Infectious diseases - mainly avoid exposure e.g. miminise exposure to toxoplasmosis via avoiding consumption of undercooked meat, avoid listeria by not eating unpasteruised dairy products
Vit A - DONT eat liver as high in vit A

Question 2

Screening tests for antenatal diagnosis: maternal blood (5)

Answer 2

Blood group & Abs - for rhesus and other incompatibilites
HIV
Hep B
Syphillus
Rubella
Down syndrome
Neural tube defects - raised maternal serum AFP

Question 3

Screening tests for antenatal diagnosis: US screening (5)

Answer 3

Gestational age
Multiple pregnancies
Structural defects - pickup rate is getting better (70%)
Fetal growth (via abdo circum, head circum, femur length)
Oligohydramnios - reduced vol of amniotic fluid e.g. due to reduced urine production (poss absent kidneys) or PROM. this can result in pulmonary hypoplasia + facial deformities due to lack of protection from pressure (Potter syndrome)
Polyhydramnios - associated with maternal diabetes & structural GI abnormalities e.g. atresia in fetus

Question 4

Techniques used for antenatal diagnosis: amniocentesis (2), Chorionic villus sampling (3) Preimplantation genetic diganosis (PGD)

Answer 4

amniocentesis (>15 weeks) - analyzes DNA & chromosome for genetic abnormalities, foetal infection
Chorionic villus sampling - (>10 weeks) chromosome/DNA analysis, fetal infection- PCR, enzyme analysis - errors of metabolism
PGD - if IVF allows genetic testing of embryo prior to implantation

Question 5

Pre-eclampsia - mangagement (1), complication (1)

Answer 5

Pre-term delivery due to potential of placental insufficiency/ IUGR & maternal stroke

Question 6

Monitoring of growth-restricted fetus (in utero) (4)

Answer 6

measure growth parameters
biophysical profile - amniotic fluid, fetal movement
Doppler US of umbilical + MCA - absent or reveral of flow in umbilical artery during diastole has a high risk of hypoxic damage

Question 7

Main problems for the infant associated with multiple births (5)

Answer 7

Pre-term labour - avg gestation for twins = 37 weeks, triplets = 32 weeks & this is the main cause for perinatal mortality of multiple births
IUGR
Congenital abnormalities - twice as frequent, 4 times increased risk if monochorionic twins
Twin-Twin transfusion syndrome - only in monochorionic twins - can cause extreme preterm delivery, fetal death
Complicated deliveries - due to malpresentation of 2nd twin at vaginal delivery

Question 8

Maternal conditions: Diabetes mellitus - poorly controlled is associated with (4), foetal complications (3), neonatal problems (4)

Answer 8

Association - polyhydramnios, IUGR, unexplained fetal death, pre-eclampsia,
Fetal complications - congenital malformations e.g. cardiac malformations, sacral agenesis, IUGR, Macrosomia; fetal hyperglycaemia > increased insulin > excess growth promotion > shoulder dystocia/ asphyxia
Neonatal problems - Resp distress, HCM, hypoglycaemia, polycythaemia infant looks plethoric

Question 9

Maternal conditions: hyperthyroidism - effects on fetus/ neonate (4)

Answer 9

If mother has grave’s ciculating thyroid stimulating abs can cross placenta - hyperthyroid fetus!
May see goitre, fetal tachy (on CTG),
neonate - weight loss, HF, diarrhoea, exopthalmus

Question 10

SLE: fetal complications (3), neonatal lupus syndrome (2)

Answer 10

recurrent miscarriage
IUGR
Pre-eclampsia, placental abruption, pre term delivery
neonatal lupus syndrome (if anti Ro or La abs) - self limiting rash, rarely heart block

Question 11

Autoimmune thrombocytopenic purpura - complications (1)

Answer 11

Maternal IgG crosses placenta and attacks fetal platelets > fetal thrombocytopenia: increases risk of: intracranial haemorrhage following birth trauma
should give these infants Iv Ig or platelet transfusion if acute bleeding

Question 12

Fetal alcohol syndrome features (4)

Answer 12

thin upper lip
absent philtrum
epicanthal folds
saddle shaped nose
maxillay hypoplasia
strawberry naevus

Question 13

Smoking - complications (4)

Answer 13

miscarriage, still birth, IUGR, reduced BW

Question 14

Drug abuse - general risks (2), cocaine (2), opiates (2), amphetamines (2)

Answer 14

Hep B/C, HIV risk
Cocaine - placental abruption, preterm delivery
opiates - prematurity + IUGR, seizures
amphetamines - GI + cerbral infarctions

Question 15

Potential adverse affects due to drugs given during labour

Answer 15

opiods - resp suppression at birth
epidural - maternal pyrexia
sedatives - may cause sedation, hypothermia
oxytocin & prostoglandin - hyperstim of uterus > fetal hypoxia (also small increase in Br levels post birth)
IV fluids - neonatl hyponatraemia - unless contain adequate sodium ofc

Question 16

CMV: features (4)

Answer 16

common cause of childhood blindness & handicap
10% of infected neonates affected at birth - IUGR also thrombocytopenia, pneumonia, mental retardation .
(RCHEP - Retinitis, colitis, hepatitis, encephalitis, pneumonitis)

Question 17

Rubella - main complication

Answer 17

cataract

Question 18

Toxoplasmosis gondii: transmitted by (2), complications (3)

Answer 18

Raw/undercooked meat + cat faeces > retinopathy + cerebral calcfication + hydrocephalus

Question 19

Parvovirus - main complication

Answer 19

aplastic anemia

Question 20

Varicella zoster (chicken pox) Features (3), management (2)

Answer 20

F - skin scarring, ocular damage, digital dysplasia,
Vesicular rash 5 days before or 2 days after delivery
manage - VZIg + treat mother with acyclovir

Question 21

Syphilis - features (3)

Answer 21

Rash on soles of feet; hand + bone lesions > treat with penicillin

Question 22

APGAR score: 5 categories & list 0, 1, 2 (points)

Answer 22

Heart rate: 0, 100
resp effort: 0, gasping/irregular, regular strong cry
muscle tone: Flaccid, some limb flexion, Well flexed & active
reflex irritability: none, grimace, cry/cough
colour: blue, pink with blue extremities, pink

Question 23

Birth weights: macrosomic, normal, LBW, VLBW

What defines small for dates/gestational age? (1)

Answer 23

> 4.5 kg

2. 5-4.5 kg
3. 5-2.5kg

Question 24

Asymetrical growth restriction: define, pathophysiology, associations (3), prognosis (1)

Answer 24

Asymetrical - abdo circumfrence on lower centile than head. this happens when placenta provides insufficient nutrients LATE in pregnancy, such that BRAIN SPARED at expense of liver glycogen & skin fat.
Associations - uteroplacental dysfunction secondary to: maternal smoking, multiple pregnancies, pre-eclampsia
Prognosis - Fetus rapidly gains weight post natally

Question 25

Symmetrical growth restriction:

Answer 25

Symmetrical - head circum equally reduced, indicates PROLONGED period of poor intrauterine growth - starting in EARLY pregnancy
Causes - fetal chromosomal disorder/ syndrome
Congenital infection, maternal drug/alc abuse
Prognosis - likely to remain permanently small

Question 26

Complications/ issues after birth of growth restricted infants: (aemias)

Answer 26

Hypothermia - because of large SA
hypoglycaemia - from poor fat/glycogen stores
Hypocalcaemia
Polycythaemia

Question 27

Large for gestational age infants: defintion (1), assocations (2), complications (3)

Answer 27

BW > 90th centile
A - maternal diabetes or GDM, fetal syndrome e.g. Beckwith-Wiedemann syndrome
C - birth asphyxia (due to diff delivery), trauma - shoulder dystocia, hypoglycaemia (due to hyperinsulinaemia), Polycythaemia

Question 28

Neonatal examination: testing for developmental dysplasia of the hip - barlow & ortalani manoeuvres

Answer 28

Barlow: stabilise pelvis > put middle finger on greater trochanter + thumb around distal femur > hold hip FLEXED + ADDUCTED > push femoral head downwards > if dislocates go on to ortalani manoeuvre
ortalani manoeuvre: apply upward leverage > dislocated hip pops back into acetabulum with a ‘clunk’

Question 29

Haemorrhagic disease of new born: causes (3), features (4), prevention (1)

Answer 29

C - vit K def, solely breast fed (no vit K - high in formula milk), maternal anticonvulsant therapy (inhibits coagulating factors), neonatal liver disease
F - haematemesis, bruising, malaena, prolonged bleeding from umbiilical stump or after circumcision. If severe can cause intracranial haemorrhage > death/disability in 50%
Prevention - IM vit K for all neonates

Question 30

Guithre test (biochem screening)

Answer 30

Performed on day 5-9 via heel prick, screening for:
PKU (phe levels)
CF (look for immunoreactive trypsin - raised if pancreatic duct obstruction)
MCAD - rare mitochondrial defect in fatty acid metabolism, so if fast > hyopglycaemia (life threatening)
Hypothyroidism
Haemoglobinopathies

Question 31

New born hearing screening: EOAE & AABR

Answer 31

Evoked otoacoustic emission (EOAE) test: earphone placed over ear > sound emitted > evokes an echo from ear IF normal cochlear function. If abnormal > Automated auditory brainstem response (AABR) > computer analysis of EEG waveforms in response to series of clicks

Question 32

Port wine stain: association with a syndrome (1), management (1)

Answer 32

Present from birth + grows with infant
Rarely may be assocaiated with vascular anomalies - Sturge-Weber syndrome or sevrere lesions on the limbs with bone hypertrophy (Klippel Trenauanay syndrome)
M - disfiguring lesions can be treated with laser

Question 33

Strawberry naevus: describe + indications for management (2)

Answer 33

A cavernous haemangioma - will see a raised red lesion > common in pre term. Regresses after 15 months
Treat if obstructing vision/ airway e.g. steroids, laser

Question 34

Heart murmur: what to do if hear one (3)

Answer 34

Most resolve spontaneously, may indicate congenital heart disease.
Do upper + lower limb BP, pulse ox, advise on cyanosis + poor feeding + arrange follow up