Full term (37 to 42 weeks gestation)
Post term (born after 42 weeks gestation)
A normal pregnancy
lasts for about 40 weeks; a baby born 3 or more weeks early is premature.
Babies who are born closer to their due dates tend to have fewer problems than
babies born earlier. But it is also proved that even those who are born late
preterm (closer to 37 weeks) are at risk for problems. It has been found that speech and
language development during early childhood in preterm infants is often delayed.
premature labor develops and cannot be stopped, the mother is moved to a center
that specifically cares for premature infants, that is, a neonatal intensive
care unit (NICU). Thus, infants are cared for in the NICU at a time when
they normally would be listening to and learning their mother's speech while in
sensory experiences and auditory environment of the infant born at less than 32
weeks of gestation in the NICU are very different from those of the fetus in
the uterus of the same gestational age. While the fetus is in the uterus, the
maternal voice is a prominent stimulus during the development of the auditory
or hearing system. Even at 23 to 25 weeks of gestation, the auditory system of
the fetus is sufficiently mature as they respond to external sound.
known that early language experience is necessary for the normal development of
speech and language. The rate of the
vocabulary growth and IQ score are more strongly related to the number of words
the parent says per hour to the child than to any other variable, including
parents' education level and the socioeconomic status of the family.
in children aged between 2 to 36 months have clearly shown that the more
parents talk to their children, more quickly their vocabularies grow and they
also end up with higher IQ test scores at age 3.
altered sensory experience for the preterm infants in the NICU may somewhere
contribute to their tendency for language delay.
to address this issue amongst preterm infants, a study was conducted to
describe the language environment to which a preterm infant is exposed in the
NICU. The study, which was published in the Pediatrics journal, hypothesized
(1) Preterm infants would produce vocalizations as early as 32 weeks' gestation,
(2) Preterm infants who were exposed to more adult language while in the NICU would
respond with more vocalizations.
study included 36 preterm infants who had a birth weight of less than or equal
to 1250 g.
recordings of the infant sound environment were made in the NICU at around 32
and 36 weeks. Adult word counts, infant vocalizations, and conversational turns
were analyzed. These were calculated using a language processor placed in the
infant's vest. A conversational turn was a sound from the infant such as a coo
or a squeal within 5 seconds of an adult word, or an adult word followed by a
sound from the infant within 5 seconds.
The results of the study put up important findings. It was
found that the
vocalizations are present as early as 32 weeks.
adult word counts per hour and infant vocalizations per hour increase
significantly between 32 and 36 weeks. In
the study it was found that when a parent was present, infants had more
conversational turns per hour than when a parent was not present at both 32 and
These findings highlight the powerful
impact that parent talk has on the appearance and increase of vocalizations
amongst the preterm infants in the NICU.
Thus the study very much makes evident
the facts that:
Very preterm infants are cared for in
an environment which has very little adult language.
Very preterm infants begin to make
vocalizations much before the expected due dates and the vocalizations increase
in number with time.
Also, infants vocalize significantly
more when a parent is visiting.
Hence, the study findings depict the
powerful impact that the parent visiting in the NICU has on early vocalizations
among preterm infants. Parents should be
encouraged to visit and communicate with their preterm infants in the NICU to
help in their language and IQ growth.
of Parent Talk on the Development of Preterm Infant Vocalizations; Melinda et
al; PEDIATRICS 2011.