Weight Profile of Preterm Infants: A Longitudinal Study Sujoy Banerjee Hesham Naseef Anitha James Mallinath Chakraborty

Overview Background Growth Charts in the UK Unsuitability Aims of Study Methods of Study Results Conclusions and Future Directions

Background

Growth Charts in the UK

Tanner 1966 (Tanner, Whitehouse et al. 1966)

UK 1990 (Freeman, Cole et al. 1995)

New Growth Charts (Cole, Wright et al. 2012)

NICM

Unsuitability Cross-sectional data from the population. Preterm infants are smaller than foetuses of the same (corrected) gestation who remain in utero (Secher et al. 1987). These charts show “birth size for gestation”, and do not contain post-natal data. None of the original studies, who contributed data for the UK 1990 charts, included Welsh infants.

Aims Collect gestation-specific longitudinal growth data of Welsh infants Compare data with UK-WHO preterm data (on which NICM charts are based)

Methods

Data Source Badgernet (CleverMed Systems) January 2011 – December 2014 (4 years) < 32 weeks gestational age at birth All longitudinal weight data, and demographics All admission episodes combined Data cleaned manually Also data on clinical variable collected Ventilation days TPN days Postnatal steroids Morbidity outcomes

Analysis Data sorted in stages by gender, gestation Analysed as gestation groups 23 – 25 weeks 26 – 28 weeks 29 – 31 weeks Z-score tested by single-sample two-tailed Student’s t test Expressed as means and 95% confidence intervals Multivariate analysis for clinical variables p < 0.05

Results

Demographics 23 – 25 weeks26 – 28 weeks29 – 31 weeks Total number Male:Female89:82225:200483:408 Birthweight (grams)722 (702 – 742)1019 (998 – 1040)1467 (1446 – 1487) Stay duration (days)72 (63 – 80)71 (68 – 75)42 (41 – 44) Discharge weight (grams)2129 (1931 – 2327)2506 (2420 – 2593)2303 (2263 – 2343) Discharge z-score-1.0 (-1.2 to -0.8)-1.0 (-1.1 to -0.9)-0.9 (-1.0 to -0.8) Ventilation days29 (19 – 40)10 (9 – 11)2 (1 – 3) Respiratory support days57 (45 – 68)41 (38 – 44)12 (11 – 13) TPN days24 (13 – 35)17 (15 – 19)9 (8 – 10) Dexamethasone days9 (0 – 20)4 (0 – 10)-

Gestation

Weight Gain: 23 – 25 Weeks

Weight Gain: 26 – 28 Weeks

Weight Gain: 29 – 31 Weeks

Z-Score: Weeks

Z-Score: 26 – 28 Weeks

Z-Score: 29 – 31 Weeks

Male: weeks

Male: 26 – 28 Weeks

Male: 29 – 31 Weeks

Female: 23 – 25 Weeks

Female: 26 – 28 Weeks

Female: 29 – 31 Weeks

Multivariate Analysis Variablep-value Birth gestation (weeks)< Stay days0.172 Ventilation days0.046 Respiratory support days< TPN days0.868 Dexamethasone days0.023

Conclusions

Summary Conclusions Significantly lower weight gain profile Male infants do worse than female infants in all gestation groups Effect possibly unrelated to TPN Cross-sectional standards (UK 1990) unsuitable to monitor weight gain in preterm infants < 32 weeks Limitation Role of nutrition, if any, cannot be confirmed from our dataset Future direction Prospective longitudinal data collection for reference standards

References Tanner, J. M., R. H. Whitehouse and M. Takaishi (1966). "Standards from birth to maturity for height, weight, height velocity, and weight velocity: British children, I." Arch Dis Child 41(219): Tanner, J. M., R. H. Whitehouse and M. Takaishi (1966). "Standards from birth to maturity for height, weight, height velocity, and weight velocity: British children, II." Arch Dis Child 41(220): Freeman, J. V., T. J. Cole, S. Chinn, P. R. Jones, E. M. White and M. A. Preece (1995). "Cross sectional stature and weight reference curves for the UK, 1990." Arch Dis Child 73(1): Cole, T. J., C. M. Wright, A. F. Williams and R. G. C. E. Group (2012). "Designing the new UK-WHO growth charts to enhance assessment of growth around birth." Arch Dis Child Fetal Neonatal Ed 97(3): F Secher, N. J., P. Kern Hansen, B. L. Thomsen and N. Keiding (1987). "Growth retardation in preterm infants." Br J Obstet Gynaecol 94(2):