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Indian Pediatr 2017;54: 627-628 |
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Late Preterm Birth and Growth Failure in
Childhood: What do we do now?
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Girija Natarajan
Professor of Pediatrics and Co-Chief, Division of
Neonatology, Wayne State University School of Medicine, Detroit, MI,
USA.
Email: [email protected]
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I n the past decade, there has been an increasing
recognition that late-preterm (340/7 to 366/7 weeks)
infants are not merely "near-term" infants [1]. A range of neonatal
problems, mainly due to immaturity and difficulties in respiratory
transition, has been identified in this population. Increased
health-care utilization, short-term morbidities and adverse
neurodevelopmental outcomes in childhood in late-preterm infants, in
comparison to infants born at term, have also been described in a rich
body of literature [1,2]. What remains unclear is the long-term medical
impact of late preterm birth. This knowledge gap is particularly stark
for late preterm infants who were relatively well in the neonatal period
and discharged home within 48 hours of age.
In this issue of Indian Pediatrics, Gupta and
colleagues [3] report the results of a prospective longitudinal cohort
follow-up study of 200 late preterm infants and 199 term controls. The
participating infants were enrolled from a single center in Northern
India, predominantly from the lower socioeconomic class, and details of
medical morbidities, mortality and growth measures were collected at 12
months chronological age. The follow-up rate was fair at about 80%.
Consistent with previous reports, the late preterm cohort experienced a
greater incidence of feeding difficulties, jaundice, fever and diarrheal
episodes, and re-hospitalization through a year of age. Exclusive
breastfeeding was lower and difficulties in latching were reported by
care-givers, which could have been the antecedent to the infectious
complications during infancy. The striking finding of the study was the
4.1-fold risk of being underweight at 12 months among healthy late
preterm infants, after adjustment for maternal weight, gender,
socioeconomic status and exclusive breastfeeding. One previous
population-based study from Brazil showed an increased risk of being
underweight at both 12 and 24 months of age among late preterm infants
[4]. The current study [3] confirms growth failure during infancy, but
shows a lower rate of weight gain during infancy in late preterm
infants. The rate of increase of head circumference was higher than
among term controls and length gain was comparable in the two groups;
these results may suggest the beginning of catch-up growth. In a recent
study [5] in 108 late-preterm individuals, for every standard deviation
faster weight and head growth from birth to 5 months and head growth
from 5-20 months corrected age, there was a 0.19-0.41 standard deviation
increase in IQ at 24-26 years of age. In contrast, rapid catch-up growth
is thought to be associated with obesity, adverse lipid profile and
chronic diseases in adulthood. In any case, whether the growth failure
at 12 months is transient or persists into adulthood, the implications
are serious. In a systematic review of studies from low- and
middle-income countries [6], undernutrition in childhood was associated
with high glucose concentrations and elevated blood pressure in
adulthood, after adjustment for adult body mass index and height. The
finding of growth failure until 12 months of age in a cohort of well
appropriate-for-gestational age late preterm neonates, who did not
manifest any neonatal signs of immaturity, is sobering.
Another finding of the study by Gupta, et al.
[3] was that mortality until 12 months of age was statistically
comparable between late preterm infants and their term-born
counterparts, although the raw number of late preterm infants who died
was more than double the term infants. In a previous study [7] using
linked birth and death data in the United States over several years,
infant mortality rates in the year 2002 were 3 times higher in
late-preterm infants than term infants (7.9 versus 2.4 deaths per
1000 live births); early, late, and post-neonatal rates were 6-, 3-, and
2- times higher, respectively. During infancy, the leading causes of
death in late preterm infants were congenital malformations (leading
cause), newborn bacterial sepsis, and complications of placenta, cord,
and membranes. The current study failed to show a difference in
mortality probably due to the limited sample size and exclusion of
infants with congenital anomalies.
So, what do we do with this new information? First,
as the authors point out, these data should raise awareness of the
unique vulnerability of late preterm infants. They should be treated as
high-risk and monitored closely for breastfeeding success, jaundice,
nutritional intake and growth, with prompt nutritional intervention,
when necessary. The impact of nutritional surveillance and intervention
on further outcomes needs to be investigated. Second, pediatricians need
to highlight to the public and to our obstetric colleagues that delivery
earlier than 39 weeks of gestation carries medical and
neurodevelopmental risks that extend into childhood, and possibly,
through adulthood. Finally, multiple randomized controlled trials,
including 3200 women at 34-36 6/7
weeks’ gestation and at risk of imminent premature delivery, have shown
that infants exposed to antenatal betamethasone had a significantly
lower incidence of transient tachypnea of the newborn (RR 0.72, 95% CI
0.56 to 0.92), severe respiratory distress syndrome (RR 0.60, 95% CI
0.33 to 0.94), and use of surfactant (RR 0.61, 95% CI 0.38 to 0.99) [8].
The impact of antenatal betamethasone on growth outcomes, especially in
low- and middle-income late preterm populations, needs to be studied.
Funding: None; Competing interests: None
stated.
References
1. Raju TN, Higgins RD, Stark AR, Leveno KJ.
Optimizing care and outcome for late-preterm (near-term) infants: A
summary of the workshop sponsored by the National Institute of Child
Health and Human Development. Pediatrics. 2006;118:1207-14.
2. Cheong JL, Doyle LW, Burnett AC, Lee KJ, Walsh JM,
Potter CR, et al. Association between moderate and late preterm
birth and neurodevelopment and social-emotional development at age 2
Years. JAMA Pediatr. 2017;171:e164805
3. Gupta P, Mital R, Kumar B, Yadav A, Jain M,
Upadhyay A. Physical growth, morbidity profile and mortality among
healthy late preterm neonates. Indian Pediatr. 2017;54: 629-34.
4. Santos IS, Matijasevich A, Domingues MR, Barros
AJ, Victora CG, Barros FC. Late preterm birth is a risk factor for
growth faltering in early childhood: A cohort study. BMC Pediatr.
2009;9:71.
5. Sammallahti S, Heinonen K, Andersson S, Lahti M,
Pirkola S, Lahti J, et al. Growth after late-preterm birth and
adult cognitive, academic, and mental health outcomes. Pediatr Res.
2017;81:767-74.
6. Victora CG, Adair L, Fall C, Hallal PC, Martorell
R, Richter L, et al.; Maternal and Child Undernutrition Study
Group. Maternal and child undernutrition: consequences for adult health
and human capital. Lancet. 2008;371: 340-57.
7. Tomashek KM, Shapiro-Mendoza CK, Davidoff MJ,
Petrini JR. Differences in mortality between late-preterm and term
singleton infants in the United States, 1995-2002. J Pediatr.
2007;151:450-6.
8. Saccone G, Berghella V. Antenatal corticosteroids
for maturity of term or near term fetuses: systematic review and
meta-analysis of randomized controlled trials. BMJ. 2016;355:i5044.
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