Neonatal period Flashcards
Essential transitions a child makes when born
- Removal of placenta
- Respiratory: clearing fluids and opening alveoli
- Cardiovascular: reducing pulmonary vascular pressure and closure of ductus arteriosus
Major causes of morbidity and mortality in neonates
Necrotising neterocolitis
Infection
Brain injury
Definition of macrosomia
>4kg at birth (8.8lbs)
What is meant by neonatal mortality?
Deaths occurring in first 28 days following birth
UK rate = ~3 per 1000 live births
What is perinatal mortality?
Deaths up to 7 days from bith AND stillbirths
UK rate ~7-8 per thousand total births
What is infant mortality?
Deaths up to 1 year
Ways to help reduce PTB
· Continuity midwife led care
· Foetal and umbilical doppler for high risk pregnant women
· Screening for lower genital tract infections
Vitamin D supplements
What 4 areas does the newborn physical examination look at?
- Heart
- Eyes
- Hips
- Testes
When is the newborn blood-spot test done?
When baby is 5 days old
What does the newborn bloodspot test screen for?
Sickle cell disease
Cystic fibrosis
Congenital hypothyroidism
6 metabolic diseases
Epidemiology of sickle cell disease
1/2000 in the UK born with sickle cell
Screened for in newborn blood spot test to allow for early treatment
Epidemiology of cystic fibrosis
1/2500 in the UK
Epidemiology of congenital hypothyroidism
1 in 3000
How is gestational age calculated?
Age measured from the first day of the LMP before conception, expressed in complete weeks or days
How is corrected age calculated?
Chronological age minus the number of weeks born before 40weeks
What is spontaneous abortion/ miscarriage?
Conceptus born after spontaneous labour without any signs of life before 24 weeks gestation
Define the neonatal period
Birth to 28 days after birth or if baby preterm, 44 weeks post-menstrual age
Define preterm birth
Born before 37 completed weeks (8% births)
When is a baby considered as being born at term?
Between 37-42 completed weeks
What weight is considered low birth weight?
<2500g
7% births UK
What is very low birth weight?
<1500g
1.2% births
What is extremely low birth weight?
<1000g
When is a child said to be small for gestational age?
<10th centile for gestational age
When is a child said to be large for gestational age?
>90th centile for gestational age
How is small for gestational age classified?
Symmetrical or asymmetrical?
Symmetrical: all growth parameters are small, suggests foetus affected from early pregnancy
Asymmetrical: weight centile < head circumference and length, usually due to a cause late in pregnancy e.g. pre-eclampsia. Asymmetrical SGA babies are at higher risk of complications
Causes of small for gestational age?
· Small parents - most common
· Restricted foetal nutrients e.g. oxygen or glucose
· Foetal abnormality e.g. chromosomal disorders/ infection
· Maternal substance use
Complications of being small for gestational age
· Increased risk of foetal death
· May have infection
· Hypoglycaemia due to reduced glycogen stores
· Hypothermia
· Polycythaemia if chronic intrauterine hypoxia
· Necrotising enterocolitis due to bowel hypoxia
· Thrombocytopenia/ neutropenia/ coagulopathy
· Meconium aspiration - foetal hypoxia = loss of anal tone
Management of baby small for gestational age
· Manage on ward with increased midwife ratio
· Evaluate for cause
· Maintain body temp and check glucose
· Admit to neonatal unit if BW <1800g
· Discharge when baby is feeding 3-4hrly, gaining 20-30g/day and body temp is maintained, providing mum is able to care for baby
Prognosis of small babies
- Neurodev problems more likely if SGA
- Symmetric SGA infants often stay small
- Barker hypothesis: suggests infants with small placenta are at risk of coronary disease, stroke, obesity and HTN later in life
Causes of baby being large for gestational age
· Most frequent cause is large parents
· Infant of mother with DM
· Hydrops fetalis
· Beckwith-Weidemann syndrome
Complications and management of large babies
Complications
- Perinatal asphyxia, nerve palsies, shoulder dystocia, fractures
- Hypoglycaemia
Management
- Careful obstetric management to avoid complications
- Examine for any signs of injury
- Prevent hypoglycaemia
What are the consequences for an infant with a mother with diabetes?
Maternal hyperglycaemia leads to increased glucose in the foetus leads to increased insulin secretion by the foetus which leads to macrosomia, organomegaly and polycythaemia.
· This is because insulin secretion antenatally functions as growth hormone
- Hypoglycaemia may develop due to high insulin levels leading to a lack of glucose in the blood, respiratory disease and obstetric complications are also more likely
- Normoglycaemia occurs within 48 hours in most, however the child has a 7x increase risk of diabetes in later life and an increased risk of obesity
What is an APGAR score?
· Appearance, Pulse, Grimace, Activity, Respiration
· Score =<6 at 1 min indicates baby needs to be resuscitated
• APGAR score noted at 1, 5 and 10 mins
How is the temperature of preterm babies managed?
PTB babies are likelt to become cold
>28 weeks: dried, warm towel and placed under heater
<28 weeks: sandwich bag without being dried and placed under heater
Baby has been towel dried but isn’t breathing - management?
Give 5 breaths via bag mask
Ratio of chest compressions to breaths in newborn
3:1 - started after 5 rescue breaths
Which factors predispose to prematurity?
· 40% of cases are idiopathic, previous preterm birth, multiple pregnancy, maternal illness such as pre-eclampsia, chorioamnionitis and diabetes, PROM, you try malformations or cervical incompetence, dysfunctional sunder and poor maternal health
What problems are associated with prematurity?
Respiratory distress syndrome
Intraventricular haemorrhage
Retinopathy of prematurity
Necrotising enterocolitis
Impaired immune system
PDA
Jaundice: immature liver enzymes
Birth trauma
SIDS
Behavioural problems
NAI: also assoiated with higher risk of marriage breakup due to stress
Hypothermia in a baby
<36 degrees
Occurs because babies have thin skin, little fat and a large body surface area
Baby will be nursed in heated, humidified incubators with a hat to reduce heat loss
Hypothermia is associated with increased mortality
When do immunoglobulins cross the placenta to baby?
30 weeks - babies born before this are at increased risk of infection
Why are pre-term babies at increased risk of infection
- Before 30 weeks they won’t have any immunoglobulins from mum
- Thin skin
- Invasive device - route for infection e.g. ET tubes, central lines
- Antibiotics make babies more susceptible to fungal infection so some units give prophylactic anti-fingls to babies born <28 weeks
Why is feeding a preterm baby difficult?
- Fragile guts: vulnerable to necrotising enterocolitis
- Deficient suck and swallow reflex until 34 weeks
- When baby is able to feed, they tire quickly because they are so small
Up to 34 weeks babies receive TPN, milk is gradually introduced during this time via NG tube
Breast milk preferred as contains immunoglobulins and less risk of nectrotising enterocolitis
Which resp. conditions are associated with prematurity?
- Respiratory distress syndrome
- Transient tachypnoea of the newborn
- Congenital pneumonia
- Bronchopulmonary dysplasia
What is respiratory distress syndrome?
o Caused by lack of surfactant in the lungs causing widespread alveolar collapse
o Common in babies born before 28 weeks can also occur in term infants, especially if mother has diabetes
o Impaired surfactant synthesis and secretion leads to stiff lungs therefore increased effort to breathe
Clinical features of respiratory distress syndrome
o Signs of respiratory distress at delivery or within four hours of birth
• Tachypnoea, grunting, intercostal recession, cyanosis
What will a CXR show in resp. distress syndrome?
Ground glass apperance
How is respiratory distress syndrome managed?
o Giving steroids to the mother during the antenatal period if there is a threat of preterm delivery
o If baby has signs of respiratory distress after birth that are severe enough to require mechanical ventilation they are given exogenous surfactant via an ET tube as soon as possible and oxygen is given to maintain saturations (usually only done in babeis born <27 weeks)
o If severe baby, will need oxygenating via mechanical ventilation, if babies saturations are more than 91% mechanical ventilation is unnecessary and oxygen is given via nasal cannula or CPAP
• Complications of mechanical ventilation: pneumothorax, pulmonary haemorrhage and chronic lung disease
After which week is respiratory distress syndrome rare?
32 weeks
Investigation for respiratroy distress syndrome?
Largely clinical
CXR: ground glass
ABG: hypoxia
Prognosis following respiratory distress syndrome
• Prognosis: the majority of babies have a good recovery, mortality is 5–10% and depends on severity and gestational age.
Bronchopulmonary dysplasia may develop
How can respiratory distress syndrome be prevented?
Corticosteroids given in 2 doses 1–7 days before birth decreases the incidence and mortality by 40%, treat coexisting morbidities that can inhibit surfactant production such as hypothermia, acidosis and infection
What is transient tachypnoea of the newborn?
· Caused by a delay in clearance or absorption of lung fluid after birth, present within four hours after birth and is more common after elective caesarean section
· Chest x-ray shows streaky perihilar changes and fluid in the long horizontal fissures
· Treatment is supplemental oxygen, consider nasal CPAP and antibiotics, spontaneously resolved within 24 hours
Symptoms:
- very fast, labored breathing of more than 60 breaths a minute.
- grunting sounds when the baby breathes out (exhales)
- flaring nostrils or head bobbing.
- skin pulling in between the ribs or under the ribcage with each breath (known as retractions)
Congenital pneumonia
· Caused by aspiration of infected amniotic fluid, associated with prolonged rupture of membranes, chorioamnionitis and fetal hyperoxia
· Common positive bacteria include group B strep, E. coli and other gram-negative bacteria such as listeria and chlamydia
· Present in the first 24 hours and chest x-ray will show patchy shadowing and consolidation, give antibiotics and chest physiotherapy where appropriate, prognosis depends on severity and whether there is any associated sepsis or pulmonary hypertension of the neuron
What is bronchopulmonary dysplasia?
• Respiratory complication, occurs in babies with VLBW, diagnosed when the neonate still requires oxygen to maintain 95% saturation at a gestation age of more than 36 weeks
25% of VLBW infants (1.5kg) are diagnosed with bronchopulmonary dysplasia
• Caused by tissue inflammation
Clinical features: need for supplemental oxygen to maintain saturations of 95%, subcostal recession, fine crackles on inspiration
Diagnosis: diagnosed when the neonate requires oxygen after 36 weeks, chest x-ray not routinely carried out but may show areas of hyperinflation and areas of hypoinflation
Management: initial aim is to prevent bronchopulmonary dysplasia from occurring through considerate treatment of RDS and any ventilation should be given gently using lowest volumes and lowest oxygen concentrations, good nutrition to optimise lung growth and repair – neonates with chronic lung disease need extra calories because they use a lot of energy breathing. Babies can be discharged with equipment for home oxygen therapy if they are otherwise well
Most babies do well but are more prone to chest infections
What is given to babies on home oxygen due to bronchopulmonary dysplasia?
Palivizumab to prevent respiratory syncytial virus infection
2 main neurological problems associated with prematurity
- Apnoea of prematurity
- Intraventricular haemorrhage
What is apnoea of prematurity?
All babies born before 28 weeks will have apnoea which is defined as a pause of breathing for more than 20 seconds, apnoea in the premature baby is caused by immature respiratory drive, gastro-oesophageal reflex, infections, seizures, hypoxia
May need mechanical ventilation until mature enough to breathe for themselves
Caffeine is given to stimulate resp. centre to drive ventilation
Good prognosis: most apnoeas resolve by 34 weeks
What is given to stimulate resp. centre to drive ventilation in apnoea of prematurity?
Caffeine
Intraventricular haemorrhage and periventricular leukomalacia
· Acquired lesions of the CNS but effective preterm infants and cause long-term disability
IV haemorrhage: small vessels rupture in germinal matrix (vascular structure, lines ventricles) - germinal matrix regresses at 34 weeks so this bleeding doesn’t occur in babies 34 weeks+
Periventricular leukomalacia: results from ischaemic injury to oligodendrocytes in the developing brain, cytokines induced damage from a maternal or neonatal infection.
• Both of the above are usually asymptomatic and detected on cranial ultrasound, sudden deterioration in babies clinical state may indicate intraventricular haemorrhage
Diagnosis of periventricular haemorrhage and periventricular leukomalacia
• Intraventricular haemorrhage: cranial ultrasound, baby is born before 32 weeks will have at least three scans in the first weeks of life when the germinal matrix is most likely to bleed. Haemorrhages are graded according to severity from least to most or grade 1 – grade 4
• Periventricular leukomalacia: noticed at birth and all preterm babies will have a routine ultrasound scan of the head at 28 weeks and 36 weeks, if periventricular leukomalacia is present the ultrasound will show cysts in the brain (cysts occur because the white-matter surrounding the ventricles softens and dies which leaves fluid filled cyst), – if the ultrasound suggests leukomalacia is present and MRI is done to assess the extent
Management of periventricular leukomalacia and intraventricular haemorrhage
There is no treatment for intraventricular haemorrhage or periventricular leukomalacia therefore the aim is to prevent it occurring in the first place
If haemorrhage occurs: monitored via weekly USS, larger haemorrhages are associated with hydrocephalus because blood prevents drainage of CSF in the ventricles
Retinopathy of prematurity
- Abnormal proliferation of blood vessels in the retina is of premature babies – begins at 34 weeks in advance is until 45 weeks
- Incidence and severity increase with decreasing gestational age birth, risk factors are prematurity high blood oxygen saturation and prolonged oxygen therapy
- Main concern is that it can lead to visual problems including blindness
- Seen in 35% of VLBW infants