Observations of postnatal developmental activity in infants with fetal malnutrition

Vocal Characteristics of Infants at Risk for Speech Motor Involvement: A Scoping Review

PURPOSE

The purpose of this scoping review was to (a) summarize methodological characteristics of studies examining vocal characteristics of infants at high risk for neurological speech motor involvement and (b) report the state of the high-quality evidence on vocal characteristic trends of infants diagnosed or at high risk for cerebral palsy (CP).

METHOD

The PRISMA (Preferred Reporting Items of Systematic Reviews and Meta-Analyses) extension for scoping reviews was followed for reporting our review. Studies measured prelinguistic vocal characteristics of infants under 24 months with birth risk or genetic conditions known to commonly present with speech motor involvement. Fifty-five studies met criteria for Part 1. Eleven studies met criteria for synthesis in Part 2.

RESULTS

A smaller percentage of studies examined infants with or at risk for CP compared to studies examining genetic conditions such as Down syndrome. The median year of publication was 1999, with a median sample size of nine participants. Most studies were conducted in laboratory settings and used human coding of vocalizations produced during caregiver-child interactions. Substantial methodological differences were noted across all studies. A small number of high-quality studies of infants with or at risk for CP revealed high rates of marginal babbling, low rates of canonical babbling, and limited consonant diversity under 24 months. Mixed findings were noted across studies of general birth risk factors.

CONCLUSIONS

There is limited evidence available to support the early detection of speech motor involvement. Large methodological differences currently impact the ability to synthesize findings across studies. There is a critical need to conduct longitudinal research with larger sample sizes and advanced, modern technologies to detect vocal precursors of speech impairment to support the accurate diagnosis and prognosis of speech development in infants with CP and other clinical populations.

The consequences of intrauterine growth retardation: what do we know?

This paper restricts itself to a discussion of the development of term infants born small, and presumed to have suffered fetal malnutrition. They form a subgroup of low birth weight infants, and have been sparsely studied to date. Investigations have usually failed to differentiate between the kinds of fetal undergrowth exhibited at birth, and it is clear that further understanding of the processes and consequences of early behaviour based on clear categorization of the growth retardation is needed. This together with more systematic investigation of the characteristics of the families of these infants is required before effective efforts can be made to ameliorate the potential effects of fetal malnutrition. The evidence so far suggests that the development of small for gestational age infants is susceptible to environmental intervention despite its physical origins; however we are far from understanding the aetiology and the precise consequences of this complex phenomenon.

Mother-infant feeding interaction in full-term small-for-gestational-age infants

Maternal and infant behavior during feeding was assessed in 30 mother-infant dyads: 15 small-for-gestational-age (SGA) infants (birth weights below the 10th percentile) and 15 appropriate-for-gestational-age (AGA) infants (birth weights between the 25th and 90th percentiles). The groups were balanced for gestational age, sex, neonatal risk factors, and maternal age, parity, socioeconomic status, and race. Behaviors indicative of infant feeding difficulties were coded for mother and infant. The SGA mothers had higher frequencies of these behaviors than did their AGA counterparts. Qualitative ratings of interactive behavior were recorded for mother and infant: SGA infants had ratings indicative of less optimal interactions than those of the AGA group. Infant caloric intake (calories per kilogram per feeding) was calculated by first dividing the change in infant weight in grams before feeding and immediately after feeding by the infant's weight before feeding and then converting it to calories. Although no difference in caloric intake was observed between the two groups, infant behaviors and ratings were associated with caloric intake. These data suggest the importance of including neonatal behavior during feeding in the risk assessment of potential growth failure in SGA infants.