Background: The ideal pattern of postnatal growth for preterm infants is unknown. Existing preterm growth charts are based on cross-sectional birth size data, and fail to describe longitudinal growth adequately.
Objective and hypotheses: We collected longitudinal growth data of healthy preterm infants and constructed growth references from birth to term equivalent age (TEA). Our aim was to describe optimal growth under contemporary neonatal care, in comparison to babies born at same gestational age.
Method: Data of 3067 infants born at 2436 gestation weeks (GW) were evaluated. Infants with pre- or postnatal conditions possibly affecting growth were excluded. The final study population consisted of 1303 preterm infants in three GW groups (80, 169, and 1,054 infants born at 2427, 2831, and 3236 GW, respectively, 55.0% boys) with 3807/3284 weight/length measurements. Data were converted to SD using contemporary birth size references. Longitudinal growth was summarized as median curves for each postmenstrual (PM) week until TEA. Median curves were fitted by a cubic smoothing spline in R-program.
Results: Birth weight and length varied between −2.0 and 2.0SD. After birth, catch-down growth occurred in all GW groups apart from growth in length in infants born at 3236 GW. Catch-up growth started after 34 PM weeks. At TEA, the median weights were −2.0/−1.8, −0.60/−0.50, −0.60/−0.50 SD and the median lengths were −2.3/−1.8, −0.40/−0.30,−0.10/0.20SD in boys/girls born at 2427, 2831, and 3236 GW, respectively (Table 1).
|Percentage of infants with weight/length <−2SD at TEA|
|Gestation weeks||Weight (boys/girls)||Length (boys/girls)|
Conclusion: Despite modern neonatal care, still 3040% of the healthy extremely preterm infants have extrauterine growth failure at TEA when compared to growth in utero. However, the ideal growth pattern of extrauterine growth in preterm infants may not be the same as the growth in utero.
18 Sep 2014 - 20 Sep 2014