Respiratory support and feeding-milestones in small-for-gestational-age, 34-36 weeks preterm infants.

BACKGROUND

Representing a distinct group among Late-Preterm-Infants (LPIs), small-for-gestational-age (SGA; birthweight <10th centile) infants remain vastly understudied.

METHODS

We investigated maternal and infant characteristics, respiratory and feeding outcomes, and length of hospital stay (LOS) at 34-36 weeks gestational age (GA), with subgroup analyses at 34-35 and 36 weeks, comparing appropriate-for-gestational-age (AGA, n = 662) and SGA (n = 116) infants (total n = 778).

RESULTS

Both pre-existing and gestational hypertension, multiple births, mode of delivery, incidence of respiratory insufficiency, and type of respiratory support varied significantly between the three stratified GA. After adjusting for covariates, there was no significant difference in respiratory morbidities between SGA and AGA. However, SGA infants were less likely to: 1) achieve full oral-feeds (O-F) within 7-days with adjusted Odds Ratio (aOR) of 0.50; 95% Confidence Interval (CI) 0.31-0.80; 2) be discharged home within 3-days of achieving full O-F (aOR of 0.62; 95% CI 0.40-0.95), and 3) discharged home in <14-days (aOR 0.41; 95% CI 0.25-0.64).

CONCLUSIONS

In this retrospective analysis, SGA and AGA LPIs demonstrated similar respiratory morbidities. However, achievement of full O-F and LOS were longer in SGA LPIs and may in part, reflect appropriate physiological maturation and individualized care rather than a delay necessitating intervention.

IMPACT: Small-for-gestational-age (SGA) infants represent a distinct and vulnerable subgroup among late-preterm infants (LPIs). However, their specific morbidities remain understudied. Respiratory outcomes were similar between SGA and appropriate-for-gestational-age (AGA) LPIs. Gestational-age stratification (34-36, 34-35 and 36-weeks) identified outcome differences such as the interval between achieving full oral-feeds (O-F) and discharge at 36 vs. 34-35-weeks gestation. Although SGA LPIs took longer to achieve full O-F, they still experienced longer length-of-stay even after reaching full O-F suggesting additional underlying physiological adaptations may be contributing to this delay. Other than birth weight, short-term morbidities were similar between SGA LPIs with and without fetal-growth-restriction.