GESTATIONAL AGE AND SIZE (NEONATOLOGY)

INFANT MORTALITY 9-10/1,000 births causes • congenital • prematurity (RDS, intracranial hemorrhage) • asphyxia •...

INFANT MORTALITY

1. 9-10/1,000 births
2. causes

• congenital
• prematurity (RDS, intracranial hemorrhage)
• asphyxia
• infections
• sudden infant death syndrome

NORMAL BABY AT TERM

1. HR 120-160/per min
2. RR 40-60/per min
3. weight 2500-4500 g
4. glucose > 2.2
5. BP systolic 50-80, diastolic 30-40 (dependent on GA)
   

GESTATIONAL AGE AND SIZE

Definitions

1. gestational age
   • pre-term: <37 weeks
   • term:  37-42 weeks
   • post-term: > 42 weeks
2. SGA: measurements < 2 SD below mean for gestational age (GA)
3. AGA: within 2 SD of mean for GA
4. LGA: > 2 SD above the mean for GA
5. GA can be estimated using the Ballard Score

 

Infant Maturity

 

Sites	< = 36 Weeks	37-38 Weeks	> = 39 Weeks
skin	pale, translucent	pinker, smoother	pink, thick
sole creases	smooth progresses to anterior creases	anterior progresses to heal creases	increasing depth of sole creases
breast nodule diameter	<2 mm	4 mm	5-10 mm
scalp hair	fine and fuzzy	fine and fuzzy	thick and silky
ear lobe	flat, pliable, no cartilage	some cartilage	stiffened by thick cartilage
testes and scrotum	testes in lower canal, small scrotum, few rugae	intermediate scrotum full	pendulous, covered with rugae
labia and clitoris	prominent clitoris, small labia	clitoris nearly covered by prepuce	clitoris covered by prepuce large labia

 

Abnormalities of Gestational Size and Maturity Features

 

 

Features	Causes	Problems
pre-term infants < 37 weeks	infection (TORCH) maternal pathology drugs/EtOH chromosomal smoking multiple pregnancy infections placental causes	RDS, respirator}' diseases recurrent apnea feeding difficulties hypocalcemia, hypoglycemia anemia jaundice intracranial hemorrhage, cerebral anoxia hypothermia edema retinopathy of prematurity
SGA infants • asymmetric undergrowth: late onset, growth arrest	extrinsic causes: diabetes, nutrition, hypertension, multiple pregnancies, drugs. EtOH, smoking	asphyxia hypoglycemia hypocalcemia
• symmetric undergrowth: early onset, lower growth potential	intrinsic causes: infections (TORCH) meconium aspiration, chromosomal, genetic, congenital abnormalities, synaromal. idiopathic	hypothermia hyperviscosity (polycythemia) NEC PDA
LGA infants - large features	maternal DM. racial or familial factors	asphyxia, meconium aspiration, respiratory distress, TTN, PPH jaundice, hypoglycemia, hypocalcemia polycythemia, congenital abnormalities
post-term infants • wisened looking, leathery skin • meconium staining		severe asphyxia, meconium aspiration hypoglycemia birth trauma if large infant