Growth trajectory of preterm small-for-gestational-age neonates

Abstract

Aim

To assess the growth trajectory of preterm small-for-gestational-age (SGA) neonates compared to preterm non-small-for-gestational age neonates in the neonatal intensive care unit and special care nursery.

Methods

We conducted a retrospective cohort study at a large tertiary hospital in Victoria, Australia, examining neonates ≤34 weeks’ gestation admitted to the neonatal intensive care unit or special care nursery between 2013 and 2017. We categorized neonates according to their birth weight centile: <10th centile (small-for-gestational age) and ≥10th centile (non-small-for-gestational age). Growth trajectory was tracked based on serial weights obtained in the neonatal intensive care unit and special care nursery, using z-scores derived from Fenton preterm growth charts. Our primary outcome was the change in weight z-score from birth to discharge from neonatal intensive care unit or special care nursery.

Results

Of the 910 babies included, 88 were small-for-gestational age and 822 were appropriate-for gestational age. Both groups had a reduction in their weight z-score; however, SGA babies had a significantly smaller reduction (–0.62 SD compared to −0.85 SD, p < .0001). Small-for-gestational-age neonates were four times more likely to experience an increase in their weight z-score across their admission compared to neonates who were not small-for-gestational age (OR 4.04, 95% CI 2.23–7.48, p < .0001). Small-for-gestational-age neonates had an increased median length of stay, increased incidence of necrotizing enterocolitis but a reduced incidence of intraventricular hemorrhage.

Conclusions

Preterm SGA babies experience a smaller reduction in their weight trajectory compared to their appropriately grown counterparts in the neonatal intensive care unit or special care nursery.

Keywords:

• Growth trajectory
• fetal growth restriction
• intra-uterine growth restriction
• weight
• neonatal

Acknowledgements

We would like to thank the patients at Mercy Hospital for Women for participating in this research. We would also like to thank Ms Tanya Fletcher from Mercy Health for assisting with the patient databases.

Authors contributions

CM was involved in designing the study, collected the data, analyzed and interpreted the data and wrote the manuscript. FCB designed the study, analyzed and interpreted the data and edited the manuscript. RH assisted with the data analysis and editing the manuscript. JK, EK, and RH were involved in designing the study, interpreting the data, and editing the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

FB was supported by a NHMRC Early Career Fellowship (NHMRC #1142636) and a Norman Beischer Medical Research Foundation Fellowship.