Prematurity and Small for Date Flashcards
What classes a baby as being premature?
gestational age from last menstrual period is <37 weeks
What would class any baby (regardless of gestational age at birth) as being of low birth weight?
<2.5kg
What would class any baby (regardless of gestational age at birth) as being of very low birth weight?
<1.5kg
What would class any baby (regardless of gestational age at birth) as being of extremely low birth weight?
<1kg
What does small for gestational age refer to?
a birth weight below the 10th percentile for their gestational age
What is intrauterine growth restriction?
failure of growth in utero
Symmetric SGA.
- all growth parameters are symmetrically small suggesting that the foetus was affected from early pregnancy
- in babies with chromosomal abnormalities and the constitutionally small
Asymmetric SGA.
- the weight centile is less than length and head circumference
- usually due to IUGR and an insult later in pregnancy e.g. pre-eclampsia
- these babies have a high risk of complications
What are some causes of being small for dates?
- poverty/poor social support
- constitutional factors
- twins
- chromosomes e.g. Edward’s syndrome
- foetal infection e.g. CMV
- placental insufficiency e.g.due to maternal smoking, diabetes, pre-eclampsia, partial abruption
What are complications of being a SGA or premature baby?
- increased risk of death
- hypoglycaemia
- hypothermia
- polycythaemia (secondary to chronic intrauterine hypoxia)
- necrotising entero-colitis secondary to ischaemia
- meconium aspiration
What are possible long term effects of being SGA or premature?
- hypertension
- reduced growth
- obesity
- ischaemic heart disease
What makes a baby extremely preterm?
born less than 28 weeks gestation
What is the rough incidence of prematurity?
about 10%
What respiratory problems can a preterm baby have?
- respiratory distress syndrome (RDS)
- bronchopulmonary dysplasia (BPD)
- apnoea
What is respiratory distress syndrome?
deficiency of alveolar surfactant means it is more difficult for the baby to inflate its lungs and there is more effort involved with breathing
What pathophysiology occurs if respiratory distress syndrome is not addressed?
respiratory failure—hypoxia leads to decreased cardiac output—hypotension, acidosis and renal failure
What would be included in a differential diagnosis of RDS?
- transient tachypnoea of the newborn (due to fluid on lungs-usually resolves after 24hrs)
- meconium aspiration
- congenital pneumonia (due to group B strep)
What are signs of RDS?
- increased work of breathing shortly after birth (first 4 hours)
- tachypnoea
- grunting
- nasal faring
- intercostal recession
- cyanosis
What can we do to prevent RDS?
administer steroids to mothers at risk of preterm delivery e.g. dexamethasone
How would you treat RDS when the baby was born?
- oxygen input and measure sats
- intubate and give surfactant an extubatne as soon as possible to use N-CPAP
What is broncho-pulmonary dysplasia?
- when treatments for maintaining premature lungs result in damage to the baby’s lungs e.g. get O2 toxicity, pressure from ventilation causes issues
- get inflammatory changes with tissue repair leading to scarring
What might you see on chest x ray that would be suggestive of BPD?
hyperinflation (horizontal ribs)
How would BPD be treated?
- steroids
- nutrition!!! e.g. high calorie feeding
What is a minor respiratory problem that can occur if you are born premature and how is it treated?
- apnoea/ irregular breathing/ desaturations
- treated with caffeine and possibly N-CPAP
What brain problems can a premature baby have?
- intraventricular haemorrhage (IVH)
- periventricular leucomalacia (PVL)
- post haemorrhagic hydrocephalus (PHH)
How is intraventricular haemorrhage graded?
1-4 (1 best, 4 worst)
What causes intraventricular haemorrhage in preterm babies?
blood vessels in the brains of babies (especially preterm babies) are immature and fragile and can bleed into the ventricles
How can IVH be prevented?
antenatal steroids in women at risk of premature birth
How would IVH be treated?
- symptomatic
- drainage?
What is periventricular leucomalacia (PVL)?
The white matter (leuko) surrounding the ventricles of the brain (periventricular) is deprived of blood and oxygen leading to softening (malacia).
What causes PVL?
If the blood supply to an area of the brain is stopped or reduces, this causes tissue damage e.g. due to IVH
What is post-haemorrhagic hydrocephalus (PHH)?
defined as progressive ventriculomegaly caused by disturbances in cerebrospinal fluid flow or absorption following intraventricular haemorrhage. e.g. due to blood coagulation blocking ventricle outflows
What circulatory problems can a preterm baby have?
patent ductus arteriosus
What gastrointestinal problems can a preterm baby have?
- necrotising enterocolitis (NEC)
- huge nutritional requirements
What is NEC?
- ischaemic and inflammatory changes in the bowel
- necrosis of the bowel
- may be due to ischaemia related to PDA
What may be signs of NEC?
huge, swollen and shiny abdomen in preterm baby
How would NEC be managed?
- surgery
- sometimes conservative management possible with antibiotics and parenteral nutrition
What is the prognosis of a premature child?
- unpredictable even when the baby is discharged
- 1/3 die
- 1/3 have normal life or mild disability
- 1/3 have moderate or severe disability for lifetime
