Neonatal care not associated with early developmental delays in children born late preterm

Image: PD

Key study points:

1. Late preterm infants (LPIs, born between 34 weeks and 36 weeks and 6 days) who received intensive care were more likely born less mature, with lower Apgar scores and birth weights.

2. Neonatal high-dependency or intensive care in LPIs is not associated with delays in growth or cognitive, motor, and language development at three years of age.

Primer: Newborn infants are defined as being premature if they are born before 37 weeks’ gestation. Short-term complications of prematurity include temperature instability, respiratory abnormalities, glucose dysregulation and circulatory complications that may require interventional support at birth. Among preterm survivors, there is an increased risk of recurrent hospitalizations, as well as an increased risk of poor neurodevelopmental outcomes. There is great heterogeneity, however, in the clinical challenges faced by very preterm (<32 weeks) and late preterm (34-37 weeks) infants. Although previously considered to be at lower risk for these complications, emerging evidence suggests that late preterm infants (LPIs) may have persistent developmental delays when compared with infants born at term. This research does not distinguish, however, between LPIs requiring intensive care or high dependency care at birth and those not requiring such care. Little is known about the developmental outcomes of these infants as compared to other LPIs. This study hoped to address the developmental differences between these groups.

Background reading:

  1.  McGowan JE, Alderdice FA, Holmes VA, Johnston L. Early childhood development of late-preterm infants: a systematic review. Pediatrics. 2011;127(6):1111–1124
  2. 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(5):450–456, 456.e1

This [prospective cohort] study included 225 LPIs born in Northern Ireland in 2006. The study group was comprised of 103 LPIs who received any duration of intensive care or ≥3 days of high-dependency care. The control group was age-matched and composed of 122 LPIs who received no intensive care. The primary outcomes of cognition, language, and motor development were assessed quantitatively at three years of age using the Bayley Scales of Infant and Toddler Development. Secondary outcomes were height and weight at this time.

Evaluation of the primary outcome of cognitive, language, and motor development showed no significant differences between the study and control group at three years.  Similarly, in evaluation of the secondary outcome of growth, there was no significant difference in the study and control groups’ heights or weights. Infants requiring intensive care were, however, more likely to be born younger than those in the control group, with 41% of study children born at 34 weeks’ gestation, compared to 15% of control children (p = 0.001). Those requiring intensive care also had significantly lower birth weights (≤ 2500g), lower Apgar scores (≤7), and were more like to have been born by Cesarean section than the control group.

In sum:  LPIs who required intensive care or high-dependency care at birth had similar cognitive, motor, language, and growth outcomes at three years of age to age-matched controls not receiving such care. It should be noted that detecting subtle developmental delays among children without major disability is extremely complex. Children may not present with developmental concerns until after three years of age, when accumulating factors may result in delay of detectable significance, and further studies should therefore be directed at longer-term developmental outcomes in this population. Nevertheless, this study provides reassuring data on the longer outcomes of the higher-risk subset of LPIs for both parents and clinicians. A comparison of both groups to children born at term would have provided for an even more definitive assessment of developmental outcomes.

Click to read the study in [Pediatrics]

By [EH] and [DB]

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