When reviewing the leading causes of mortality and morbidity in neonates, which ONE of the following is INCORRECT?
Answer: D: When reviewing neonatal morbidity and mortality registries, most infant deaths were due to four causes (classified according to the International Classification of Diseases):
Birth weight is classified as small for gestational age (SGA), intra-uterine growth restriction (IUGR), low birth weight (<2500 g) and very low birth weight (<1500 g). SGA infants have a birth weight <10th percentile for gestational age, whereas IUGR is defined as a fetus whose estimated weight is below the 10th percentile for its gestational age and whose abdominal circumference is below the 2.5th percentile. At term, the cutoff birth weight for IUGR is 2500 g.
Approximately 70% of fetuses with a birthweight below the 10th percentile for gestational age are constitutionally small; in the remaining 30%, the cause of IUGR is pathologic.
GBS infection occurs in neonates born to women colonized with Streptococcus agalactiae. There are two main types of GBS disease; early-onset disease (occurs during the first week of life) and late-onset disease (occurs from the first week through three months of life). For early-onset disease, GBS most commonly causes sepsis, pneumonia and sometimes meningitis. A strong index of suspicion coupled with a rigorous guideline approach is required to decrease the incidence of early onset GBS disease. Most birth suites have protocols designed to identify GBSpositive women who are eligible for parenteral antibiotics if they have prolonged rupture of membranes beyond 12 hours. Neonates born to these mothers are observed carefully. Typically, if a mother who tested positive for GBS received antibiotics during labour, the baby will be observed to assess their need for septic screening because of concerns about early-onset disease. Similar illnesses are associated with late-onset GBS disease but meningitis is more common with late-onset GBS disease than with early-onset GBS disease. Late onset disease is more difficult to screen for, although most sepsis/fever algorithms have a low threshold for screening for bacterial illness in a <3-month-old child. Treatment is with parenteral antibiotics, usually ampicillin and gentamicin.
TTN is a benign condition usually occurring in term neonates born after a caesarean section who develop an oxygen requirement with moderate respiratory distress. It usually has its onset at 6–24 hours after birth and may last for up to 72–96 hours. Its aetiology is uncertain, but it is postulated that the usual forces at play during a vertex vaginal delivery are absent from a caesarean birth, with residual fluid retention in the interstitium of the neonatal lung with resultant respiratory distress. It usually resolves after a few days.
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A 10-day-old breastfed boy has been jaundiced for 2 days. No associated symptoms of vomiting or lethargy are present, and the stool pattern is unchanged. Examination reveals a well-looking baby with a weight of 2650 g. The baby was born at 35 weeks’ gestational age by spontaneous vertex delivery with a birth weight of 2700 g.
Which ONE of the following is INCORRECT?
Answer: B: Jaundice occurs in most newborn infants and is usually benign, but because of the potential toxicity of bilirubin, newborn infants must be risk stratified to identify those who might develop severe hyperbilirubinemia and, in rare cases, acute bilirubin encephalopathy or kernicterus. The following are risk factors for development of severe hyperbilirubinaemia and acute bilirubin encephalopathy:
1- Major risk factors include:
2- Minor risk factors include:
Indications for formal testing of serum bilirubin levels includes those babies with risk factors for progression to severe hyperbilirubinaemia, progressive jaundice, and babies who appear unwell, that is lethargy, poor feeding, dehydration, failure to thrive or evidence of sepsis. The total serum bilirubin should be plotted on the treatment nomogram for jaundiced babies to assess their need for admission for phototherapy. Refer to answer 4 for a further discussion on the causes of jaundice.