Neonatology Flashcards
What are the risk factors for neonatal invasive Group B Streptococcus infection?
Preterm babies PROM Maternal fever during labour Maternal chorioamnionitis Previously infected infant
What does group B strep infection cause?
Early onset sepsis - respiratory distress and pneumonia, septicaemia, meningitis
Late onset - meningitis, focal infection
How are mums and babies with GBS positive infection treated?
Prophylactic Abx can be given pre-labour
Broad spectrum Abx - amoxicillin or benzylpenicillin
How does cytomegalovirus affect the neonate?
40% risk of fetus becoming infected
90% are normal at birth and develop normally
5% have hepatosplenomegaly and petechiae –> neurodevelopmental disability
5% develop problems later in life such as sensorineural hearing loss
How does rubella affect the neonate?
Severity decreases with time of infection into pregnancy
Sensorineural deafness
Eye abnormalities - retinopathy, cataracts
Congenital heart disease - pulmonary stenosis, PDA
How does toxoplasmosis affect the neonate?
Mother consumes raw/undercooked meat or is in contact with feline faeces
40% of fetuses become infected and 10% of those have clinical manifestations
retinopathy
cerebral calcification
hydrocephalus
How are the HIV positive mother and baby managed?
Reduce maternal viral load at time of delivery
Avoid breast feeding
Avoid PROM or instrumentation
Pre-labour C-section if viral load is high
HIV PCR is done in first 3 months of life and ART given
How does syphilis affect the neonate?
Failure to thrive No nasal bridge Rash of mouth, anus and genitalia Blindness Deafness Deformities of face Neurological problems
GIVE PENICILLIN
How does chlamydia affect the neonate?
Conjunctivitis along with swelling of eyelids
Pneumonia at 4-6 weeks
GIVE ERYTHROMYCIN
How does gonorrhoea affect the neonate?
Chorioamnionitis –> premature labour
Opthalmia neonatorm - purulent discharge, lid swelling, corneal haze –> BLINDNESS
GIVE PENICILLIN
How does herpes affect the neonate?
Transmitted via infected birth canal
Can cause local disease to sites of trauma
Affect internal organs
Affect CNS -> encephalitis
What causes bilious vomiting?
OBSTRUCTION BELOW DUODENUM
Intussusception Obstruction Volvulus Malrotation Tumours Hirschsprung's Constipation
What does small for age mean?
Below 10th centile
Infants are genetically programmed to be this small
What does intrauterine growth retardation mean?
Infants are less than genetically predetermined size
Weight and abdo circumference lie on lower centile than head due to brain development taking priority
What causes IUGR?
Maternal factors:
- increased age
- HTN
- diabetes
- alcohol and drug abuse (cocaine)
- smoking
Placental causes:
- small placenta that cannot supply needed nutrients
- pre-eclampsia
Fetal causes:
- multiple pregnancies
- intrauterine infections
What are complications of IUGR?
Perinatal and neonatal morbidity Coronary artery disease Hypertension Type 2 DM Autoimmune thyroid disease
What is erythema toxicum?
Neonatal urticaria
White pinprick papules at 2-3 days old
What are Mongolian blue spots?
Blue/black discolourations on base of spine and buttocks
What is a cephalohaematoma?
Haematoma from bleeding below periosteum confined within margins of skull sutures
Resolves over several weeks
How does a brachial plexus injury arise?
During breech deliveries or with shoulder dystonia
Damage to C5+6 results in Erb’s palsy which resolves
How does sticky eye arise?
Small tear ducts become blocked by fluid and debris during birth
Eye is bathed with sterile water
How does ABO incompatibility arise?
Most ABO antibodies are IgM so don’t cross placenta
Some group O women have IgG anti-A and anti-B haemolysin
These can cross placenta and haemolyse RBC of baby
Can cause severe jaundice but less severe than Rhesus disease
What antibodies can cross the placenta?
Just IgG
How does Rhesus incompatibility arise?
Rhesus -ve mother has +ve first child
Produces IgG antibodies against +ve
If second child is +ve then antibodies will cross placenta and cause Rhesus disease
Avoided through anti-D Ig in pregnancy
What is CHARGE?
Coloboma of the eye (hole in structure) Heart defects Atresia of nasal choanae Retardation of growth +/- development Genital/urinary anomalies Ear anomalies and deafblindness
What is anencephaly?
Failure of development of most of cranium and brain
Infants are stillborn or die shortly after birth
What is encephalocele?
Extrusion of brain and meninges through midline skull defect
Can be corrected
What is spinal bifida occulta?
Failure of fusion of vertebral arch
Skin lesion over lumbar region
Underlying tethering of cord may cause neurological deficits of bladder function and lower limbs with growth
What is a meningocele?
Skin and meninges form outpouching present with spinal bifida
Cord remains in meninges so fewer problems
What is a myelomeningocele?
Communication between surface and meninges
–> paralysis, sensory loss, muscle imbalance, neuropathic bladder
How do androgens affect sex characteristics?
Excessive androgens in females –> virilisation i.e. congenital adrenal hyperplasia
Inadequate androgens - undervirilisation in males
Can be due to decreased response or inability to convert testosterone to DHT
How does gonadotrophin affect sex characteristics?
Insufficienct (Prader-Willi, congenital hypopituitarism) - small penis and cryptorchidism
What causes CAH?
Autosomal recessive disorders of adrenal steroid biosynthesis
Deficiency of enzyme 21-hydroxylase needed for cortisol biosynthesis
80% unable to produce aldosterone –> salt loss
Stimulates pituitary to produce ACTH which drives overproduction of adrenal androgens1
How does CAH present?
Virilisation of external genitalia of female infants - clitoral hypertropy and fusion of labia
Large penis and pigmented scrotum in infant male
Salt-losing adrenal crisis at 1-3 weeks - vomiting, weight loss, floppiness and circulatory collapse
Tall stature in non-salt losers
How is CAH managed?
Salt losing crisis - IV saline, dextrose and hydrocortisone
Lifelong glucocorticoids to suppress ACTH
Mineralocorticoids
How does Potters syndrome occur and present?
Bilateral renal agenesis, PKD –> decreased urine and amniotic fluid production
Oligohydramnios –> pressure in utero and decreased pulmonary development
What screening tests are done on a Guthrie test?
Congential hypothyroidism Sickle cell disease Phenylketonuria (PKU) Cystic fibrosis Medium-chain acyl CoA dehydrogenase (MCAD) deficiency Homocystinuria Maple syryp urine disease (MSUD) Glutaric aciduria type 1 Isovaleric acidaemia
