Preterm Infants Learn to Speak Fast If Parents Converse With Them
• Premature (less than 37 weeks gestation)
• 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.
When 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 the uterus.
The 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.
It is 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.
Studies 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.
The altered sensory experience for the preterm infants in the NICU may somewhere contribute to their tendency for language delay.
Therefore, 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 that:
(1) Preterm infants would produce vocalizations as early as 32 weeks' gestation, and
(2) Preterm infants who were exposed to more adult language while in the NICU would respond with more vocalizations.
The study included 36 preterm infants who had a birth weight of less than or equal to 1250 g.
Sixteen-hour 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 infant vocalizations are present as early as 32 weeks.
Both 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 36 weeks
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.
Reference: Importance of Parent Talk on the Development of Preterm Infant Vocalizations; Melinda et al; PEDIATRICS 2011.