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- How to define an infant with small for gestational age?
A neonate with birth length and/or birth weight at least 2SD below the mean for
gestational age is defined as small for gestational age (SGA). A birth weight of
<2.5 Kg in a full-term newborn is considered as small for gestational age. In
clinical practice, the term SGA is interchangeably used with intrauterine growth
retardation (IUGR).- What is symmetric SGA?
The maximum increase in fetal length occurs during early intrauterine period
(10–24 weeks), whereas maximum increase in weight occurs during
32–40 weeks. Any insult to the fetus during early pregnancy, either due to chro-
mosomal/syndromic disorders or congenital infections, affects both length and
weight, thereby leading to a neonate with symmetric SGA. These neonates do
not have catch-up growth because of early insult during gestation and eventu-
ally end up with short adult height.- What is asymmetric SGA?
Any insult to the fetus during late gestation leads to the birth of an infant with
compromised birth weight but with normal birth length, i.e., asymmetric
SGA. This usually occurs due to fetoplacental insufficiency. Infants with asym-
metric SGA usually experience catch-up growth during infancy and finally
achieve a normal adult height.- What is intrinsic short stature?
Intrinsic short stature is associated with disorders which are characterized by
inherent limitation of bone growth. The important causes of intrinsic short stat-
ure include Turner syndrome, Russell–Silver syndrome, Prader–Willi syn-
drome, and achondroplasia (Fig. 1.13).1 Disorders of Growth and Development: Clinical Perspectives