Clinical Conditions Associated with Post Natal Growth Failure in Preterm Infants

Nestor A. Dinerstein, Claudio L. Solana, Ricardo M. Nieto, Gaston P. Perez, Mario Carrara, Diana Kelma nsky, Debora Chan. Neonatology, Maternidad Sarda, Buenos Aires, Argentina; Fresenius Kabi Argentina, Buenos Aires, Argentina; Departamento de Calculo, F acultad de Ciencias Exactas, Universidad de Buenos Aires, Buenos Aires, Argentina

BACKGROUND:

Among our preterm newborn infants, at 4 0 weeks post menstrual age (PMA) 52 % are below the 10 th percentile for body weight, 47% for body length an d 8% for head circumference (HC).

OBJECTIVE:

to evaluate the influence of each perinatal clinical condition on the frequency of post natal grow th retardation (PNGR), low head circumference (HC) and short body length at 40 PMA.

DESIGN/METHODS:

cohort study. Inclusion criteria: in- born infants, <32 weeks GA, birth weight <1500 g and s urviving up to 40 weeks of PMA. Exclusion criteria: ma jor congenital malformations, intrauterine infections and infants transferred before 40 weeks. Three explicative logistical regression models were constructed estimating in each case the 95% confidence intervals for the odds ratio of the significant factors.

RESULTS:

From 08/2001 to 11/2005, 339 infants were b orn, 238 met the inclusion criteria and were studied. Clinical characteristics and outcomes were: mean birth weight: 1144 g, SD 234; mean GA: 28.4 weeks, SD 1.66; frequen cy of small for dates: 9.2%; CRIB score >5:11.3%; PNGR: 52%; low HC at 40 PMA: 8%; short length at 40 PMA: 47%; BPD: 36.6%; late onset sepsis: 26.9%; NEC: 1.7%; PDA: 46.6% and combined morbidity (PDA, RDS,BPD and late onset Sepsis): 60.1%. Multivariate analysis showed that the following variables were predictive for PNG F: gestacional age (OR:2.01, 95%CI 1.52-2.66), combine d morbidity (OR:2.85, 95%CI 1.43-5.69), birth weigh t (OR:0.53, 95%CI 0.43-0.66) and caloric deficit (OR:1.13, 95%CI 1.04-1.23). Predictive variables for short length were : gestacional age (OR:1.58, 95%CI 1.22-2.03), combine d morbidity (OR:3.09, 95%CI 1.6-5.96), birth weight ( OR: 0.54 95%CI 0.44 0.66 ) and male gender (OR:2.39, 95%CI 1 .26-4.54). Predictive variables for low HC were: bir th weight (OR:0.62, 95%CI 0.54-0.83) and male gender (OR:6.39 , 95%CI 1.76-23.23). All of the above have good Hos mer-Lemeshow adjustment and show good capacity of classification (above 72%).

CONCLUSIONS:

We found that combined morbidities such us RDS, PDA, late onset sepsis and BPD, associated with lowe r birth weight, gestacional age, male gender and caloric deficit explain PNGR , shorter body length and lower head circumference at 40 PMA weeks in our populati on. Postnatal growth failure prevention will only be possible improving nutritional interventions and reducing neo natal co-morbidities.