Neonatology Flashcards
What is considered a low birthweight in neonates?
<2500g
What is considered a extremely low birthweight in neonates?
<1000g
What is considered a very low birthweight in neonates?
<1500g
What maternal bloods are typically taken for screening?
Blood group and antibodies
HepB
Syphilis
HIV
Neural tube defects (raised alphafetoprotein)
T21, T18, T13
When should folic acid supplements be taken to reduce the risk of neural tube defects?
Pre-pregnancy and for first 12 weeks pergnancy
By how much does smoking typically affect birthweight of a newborn?
Reduced by 200g
when is gestational age typically calculated on AN USS?
11-13weeks
What measures should be taken by the pregnancy woman to avoid toxoplasmosis?
Avoid undercooked meat
Use gloves for cat litter and gardening
Which women carry an increased risk of neural tube defects in their babies?
Obese
Diabetic
On anticonvulsants
Personal or FHx of neural tube defects
What measures should be taken by the pregnancy woman to avoid listeria infection?
Avoid soft-ripened cheeses, pate and ready to eat poultry
What measures should be taken by the pregnancy woman to avoid high vitamin A concentrations?
Avoid liver
What does maternal obesity increase the risk of for the pregnant mother?
Miscarriage
GDM
Pre-eclampsia
Stillbirth
Congenital abnormalities
Macrosomia
Mortality
What measures should be taken by the pregnancy woman to avoid high mercury levels?
Avoid swordfish and limit tuna intake
What maternal factors increase the risk of fetal abnormality?
Older mother
Previous congenital abnormality
FHx inherited disorder
Parents carry AR disorder
Parents have a chromosomal rearrangement
Consanguinuity
How is fetal growth assessed on USS?
Abdominal circumference and femur length
What percentage of congenital abnormality is seen on AN USS?
Wide range 50-98% depending of abnormality
What are the potential causes of increased amniotic fluid volume?
Maternal DM
Structural GI abnormalities
What are the potential causes of reduced amniotic fluid volume?
Reduced fetal UOP
PPROM
IUGR
What can AN fetal blood sampling facilitate?
Hb for anaemia
Infection serology
Fetal blood Tx
What investigations can be done on amniocentesis?
Chromosome/microarray and DNA analysis
Fetal viral infection
What can AN CVS test for?
Chromosome/microarray and DNA analysis
Enzyme analysis of IEMs
What can fetoscopy facilitate?
Laser photo-coagulation in twin-twin transfusion syndrome
What is NIPT testing used for?
T21, T18, T13 and fetal Rh status
What is the role of tocolysis in preterm labour?
Supress uterine contractions and supress labour until AN steroids completed and transfer to a tertiary unit
What are the causes of preterm delivery?
Idiopathic
Intrauterine stretch
Endocrine maturation
Intrauterine bleeding
Intrauterine infection
Fetal IUGR or chromosomal abnormalities
Maternal medical conditions
Cervical weakness
What medications can be given to the mother to treat SVT in the fetus?
Digoxin
Flecainide
How does glucocorticoid therapy help in preterm delivery?
Accelerates lung maturity and surfactant production
Completed course given at least 24hours prior to delivery for optimal effect
What is the role of progesterone in preterm labour?
Used as a prophylactic agent in those at high risk for preterm labour
What are the epidemiological risk factors for preterm delivery?
Previous preterm infant
Short inter-pregnancy interval
Maternal age <20 or >35
Previous CS
Maternal undernutrition or obesity
Ethnicity (increased rates in black mothers)
Maternal infection
Smoking and substance misuse
Socioeconomic depravation
Maternal psychological or social stress
In the UK what percentage of deliveries are preterm (<37weeks)?
7.7%
What is the role of magnesium suplhate in preterm labour?
Reduced the risk of CP in infants
What happens to the “donor” twin in twin-to-twin transfusion syndrome?
Reduced perfusion pressures
Oliguria and oligohydramnios
Growth often restricted
What are the odds of having triplets in the UK?
1 in 8000
What are the odds of having quadruplets in the UK?
1 in 700000
What are the odds of having twins in the UK?
1 in 90
What is the risk of congenital abnormalities in a singleton pregnancy?
2%
What percentage of twins are delivered prematurely?
60%
What percentage of twins are delivered <32weeks?
11%
What is the risk of congenital abnormalities in dichorionic twins?
4%
What is the risk of congenital abnormalities in monochorionic twins?
8%
What is the risk of twin-to-twin transfusion syndrome occurring in monochorionic twins?
10-15%
What is the survival rate of twin-to-twin transfusion syndrome?
60-90%
What happens to the recipient twin in twin-to-twin transfusion syndrome?
Hypervolaemia
Polyuria
Polyhydramnios
High-output cardiac failure
What associations are there with poorly controlled DM during pregnancy and delivery?
Polyhydramnios
Pre-eclampsia
Increased rates of fetal loss, both early and late
Congenital abnormalities risk increased
What is the increased risk of IUGR of mothers with DM with microvascular disease?
3-fold increase
What is the rate of congenital abnormalities in DM and what abnormalities are more prevalent?
6%
Cardiac malformations
Sacral agenesis
Hypoplastic left colon
What causes macrosomia in children of diabetic mothers?
Maternal hyperglycaemia affects fetus as glucose crosses placenta but insulin does not
Fetus increases rate of insulin secretion which promotes increased cell number and size
What percentage of infants born to diabetic mothers are macrosomnic?
25%
What are macrosomnic babies more prone to at birth?
Birth asphyxia
Shoulder dystocia
Brachial plexus injury
What neonatal issues are associated with diabetic mothers?
Transient hypoglycaemia
RDS
Hypertrophic cardiomyopathy
Polycythaemia
Which groups of mothers are more predisposed to GDM?
Obese
Black
Asian
FHx of GDM
What is the risk of newborns of hyperthyroid mothers being hyperthyroid?
1-2%
What causes hyperthyroidism in infants of hyperthyroid mothers?
Circulation TRab which crosses placenta and binds to TSH receptors, stimulating fetal thyroid hormone production
What are the symptoms of fetal hyperthyroidism?
Fetal tachycardia on CTG
Goitre on USS
How is neonatal hyperthyroidism treated?
Anti-thyroid drugs until maternal abs clear and symptoms subside
What are the signs of hyperthyroidism in the newborn?
Tachycardia
Heart failure
Vomiting
Diarrhoea
Poor weight gain
Jitteriness
Goitre
Exophthalmos
What issues does hypothyroidism typically cause in the neonate?
If mother on therapy then nil
How does maternal ITP affect the fetus?
Maternal IgG abs cross the placeta and damages fetal platelets causing thrombocytopenia
If an infant is severely thrombocytopenic at birth, what can be given to them?
IVIG
Platelet Tx if bleeding
What is the global commonest cause of hypothyroidism?
Iodine deficiency
What can sometimes occur to infants born to mothers with anti-Ro or anti-La antibodies
Neonatal lupus syndrome
What is SLE with antiphospholipid syndrome associated with in pregnancy?
Recurrent miscarriage
IUGR
Pre-eclampsia
Placental abruption
Preterm delivery
Which antiepileptic rugs are commonly known to affect the fetus?
Sodium valproate
Carbamazepine
Hydantoins
What are the defining features of neonatal lupus syndrome?
Rash (self limiting)
Heart block (rarely)
How can Tetracycline affect the unborn fetus?
Enamel hypoplasia and yellow/brown teeth staining
How does fetal valproate/carbamazepine syndrome present?
Midfacial hypoplasia
CNS, limb and cardiac malformations
DD
How can cytotoxic agents affect the unborn fetus?
Congenital malformations
How can radioactive iodine affect the unborn fetus?
Hypothyroidism
How can lithium affect the unborn fetus?
Congenital heart defects
How does fetal alcohol syndrome present?
Decreased HC
Smooth philtrum
Thin upper lip
Small palpebral fissures
IUGR
How can SSRIs affect the unborn fetus?
Persistent pulmonary hypertension of the newborn
What does maternal smoking increase the risk of in pregnancy?
Miscarriage
Stillbirth
Abruption
Low birthweight and IUGR
How does NAS present neurologically?
Neurological excitability
- tremors
- irritability
- high pitched cry
- disturbed sleep-wake cycle
- seizures
What non-pharmacological treatments can improve the symptoms of NAS?
Skin to skin care
Gentle swaddling
Soft music
Low lighting
Massage
Breastfeeding
Keeping mum and baby together where possible
What are the GI symptoms of NAS?
Feeding difficulties
D&V
Poor weight gain
Weight loss
How can vitamin A and retinoids affect the unborn fetus?
Increased rate of spontaneous abortions
Abnormal facies
How can Warfarin affect the unborn fetus?
Interferes with cartilage formation - ocular and skeletal malformations
How can Thalidomide affect the unborn fetus?
Limb shortening
What pharmacological treatment may be required in NAS?
Morphine
Buprenorphine
Methodone
In what ways can congenital infection be confirmed in neonates?
Serology from baby or mother
Amniocentesis or CVS
Placenta PCR
Urine from infant
Blood/CSF from infant
Which immunoglobulin is raised to indicate an infection of rubella, CMV or toxoplasma in an infant or mother?
IgM
What are the autonomic signs seen in NAS?
Fever
Temperature instability
Sweating
Nasal stuffiness
Yawning
Sneezing
At what gestation is rubella infection within a mother most harmful to her unborn child?
<8weeks gestation
What does rubella infection cause to infants if the infection was present at <8weeks gestation?
Deafness
Congenital heart defects
Cataracts
What does rubella infection cause to infants if the infection was present at 13-16weeks gestation?
Hearing impairment in 30%
What does rubella infection cause to infants if the infection was present at >18weeks gestation?
Risks minimal
What are the clinical symptoms in congenital rubella infection?
Growth restriction
Eye defects
Pneumonitis
Hepatomegaly and jaundice
Virus in urine
Bone abnormalities
Intracerebral calcifications
Microcephaly
Deafness
Heart defects
Splenomegaly
Rash
Anaemia
Thrombocytopenia
Neutropenia
How does congenital CMV present at birth?
Most are asymptomatic
Hepatosplenomegaly
Petechiae
SNHL
CP
Epilepsy
Cognitive impairment
What is the treatment for neonatal syphilis?
Penicillin
What eye defects are associated with congenital rubella infection?
Retinitis
Cataracts
Microphthalmia
What percentage of children who develop congenital VZV syndrome develop a vesicular rash?
25%
What heart defects are associated with congenital rubella infection?
Cardiomegaly
PDA
How is toxoplasmosis infection acquired?
Raw or undercooked meat
Faeces of infected cats
Congenital parvovirus B19 infection is rare, but how does it present?
Usually asymptomatic
Rarely anaemia, fetal hydrops and IUD
How does fetal varicella syndrome present?
Severe scarring of skin
Ocular and neurological damage
Digital dysplasia
If infants are born in the high risk period for VZV what treatment should they be given?
VZVIG
How does congenital toxoplasmosis infection affect the newborn infant?
90% asymptomatic
Retinopathy
Acute fundal chorioretinitis
Cerebral calcifications
Hydrocephalus
How is congenital toxoplasmosis infection treated?
Pyrimethamine and sulfadiazine for 1 year
At what 2 satges of development is the fetus particularly susceptable if the mother catches chickenpox?
<20weeks gestation
In the last 4 weeks of pregnancy
7 days before or after delivery if viral load is high
What is the route of blood flow from the placenta to the heart and brain in fetal life?
Umbilical vein, into ductus venosus, into IVC, into RA, through foramen ovale, into LA
What medications should be given to mothers exposed to VZV infection?
VZVIG
Aciclovir
What percentage of children who develop congenital VZV syndrome die from infection?
30%
Congenital syphilis presents with very similar symptoms to rubella infection, but what other symptoms may also occur?
Rash on palms and soles
Bone lesions
What is the route of deoxygenated blood from the fetus back to the placenta?
SVC, into RV, into pulmonary artery, into ductus arteriosus, into lower aorta and into placenta via umbilical arteries
What should the delivery room temperature be for delivery of preterm infants?
26dgerees
Which enzyme contributes to physiological jaundice?
Uridine diphosphoglucuronyl transferase (UDPT)
What is the O2 sats of the upper body in the fetus?
65%
What stimulates reabsorption of alveolar fluid within the lungs?
Increased catecholamine levels at birth
At what gestational age should preterm infants be placed directly into a plastic wrap after birth?
<32weeks gestation
The abnormal presence of what structure leads to Meckels diverticulum?
Vitelline duct
What is the O2 sats of the lower body in the fetus?
35%
When should pCO2 parameters be changed in a premature neonate on invasive ventillation?
Day 4 (from 4.5-8.5 - 4.5-10kPa)
How does congenital rubella infection present?
IUGR
Bilateral cataracts
Cardiac anomalies
What is the embryological origin of intestinal plexi?
Ectoderm
How does congenital hypopituitarism present?
Microgenitalia
Jaundice
Hypoglycaemia
What process leads to duodenal atresia?
Failure of full recanalisation of the intestines
At what week of development does the embryo develop a gut tube?
Week 4
Which embryological layer gives rise to the gut tube?
Endoderm
When does the retinal blood vessel growth typically stop?
2-4weeks after birth regardless of gestation
What is the embryological mechanism behind congenital diaphragmatic hernia?
Failure of the pleuroperitoneal canals to close
Which of the embryological cell lines is implicated in the development of DiGeorge syndrome?
Neural crest cells
Why is haemolytic disease of the newborn usually restricted to rhesus antigen rather than ABO?
Antibodies against rhesus antigen are IgG which are the only antibody able to cross the placenta. ABO abs are IgM
In a newborn with hypotonia presenting with tongue fasciculations, what is the most likely diagnosis?
SMA
How is polycythaemia diagnosed from an FBC?
Venous Hct >65%
What stimulates fetal lung fluid reabsorption?
Glucocorticoids
What dose of adrenaline should be given to a neonate in cardiac arrest?
0.2ml/kg of 1:10000
What conditions can cause neonatal hepatitis?
Congenital infection
Biliary atresia
Galactosaemia
Tyrosinaemia
A1-antitrypsin deficiency
CF
TPN cholestasis
By what gestational age does the skin mature?
34 weeks
Which ventricle would a ventricular tap typically go into?
One of the lateral ventricles - accessed via the anterior fontanelle
Which cell membrane channel is responsible for lung fluid reabsorption?
Sodium channels
What happens to IgG levels in a premature infant?
Levels fall to trough level at around 3-4weeks of age - baby is then immunosuppressed until they are able to make their own
What type of bacteria is GBS?
Anaerobic gram +ve cocci
What test is done to confirm a diagnosis of meconium ileus?
Contrast enema
What would a contrast enema show in meconium ileus?
Small-calibre colon
Dilated proximal bowel loops
Pellets of meconium in ileum
In what structures of the lung is surfactant synthesised?
Type 2 pneumocytes
How does congenital toxoplasmosis typically present?
Cerebral calcification
Hydrocephalus
Chorioretinitis
What is the largest component of surfactant?
Phosphatidylcholine (phospholipid)
90% of surfactant is phospholipids and the above makes up 80% of these
What physiological process leads to the closure of the foramen ovale following birth?
Dilation of the pulmonary vascular bed - increases blood flow to lungs and reduced blood flow to RA.
What is microvillous inclusion disease?
Rare disorder causing secretory diarrhoea of the intestinal brush border in neonates
How is microvillous inclusion disease inherited?
AR
What infection does meconium staining in a preterm infant suggest?
Listeria
What is the classical triad of congenital toxoplasmosis?
Chorioretinitis
Hydrocephalus
Intracranial calcifications
What is the treatment for congenital toxoplasmosis?
Pyrimethamine
Sulfadiazine
Folinic acid
What is the subunit structure of HbF?
2-alpha and 2-gamma chains
What vessel follows on from the umbilical vein in neonates when an UVC is inserted?
Ductus venosus
What is the role of uridine-diphosphoglucuronic gluocuronosyltransferase (UDPGT)?
Conjugates bilirubin for excretion by the kidneys
What are the risks of exchange transfusion?
Hyperkalaemia
Hypo- or hyper- glycaemia
Air emboli
Hypocalcaemia
Acidosis
From what gestation is surfactant produced?
24 weeks
What complications can occur following removal of the ileocaecal valve in NEC?
Overgrowth of colonic bacteria in the small intestine
What is the main regulatory hormone for terminal maturation of the fetus and neonatal adaptation at birth?
Cortisol
What are the functions of cortisol in the neonate?
Lung maturation
Clearance of lung fluids
Increase of beta-receptor density
Catecholamine release
Maturation of thyroid axis
