Growth of low birth weight preterm infants after discharge

Although infants with very low birth weight (VLBW) grow and develop, the growth of a significant proportion of them at age-2 evaluation falls behind compared to their term peers. In order to prevent morbidity and mortality in these infants, it is very important to perform prenatal consultation in time, early postnatal nutrition, later nutrition and to follow carefully their growth and development. This study focuses on preterm infants with very low birth weight and aims to investigate their growth properties up to their corrected age of 2, the time to capture the growth and evaluate the factors that affect the growth. This study involved 77 preterm infants with birth weight of 1500 gram or less. These infants had been discharged from the Neonatal Intensive Care Unit of Adnan Menderes University Medical School Pediatry Department; post-discharge follow-ups were carried out by Neonatal Polyclinic of the same department. The following retrospective screening data of the cases were first obtained from their records and then were evaluated: demographic information, obstetric history, prenatal, natal and postnatal clinical findings, the follow-up duration at the hospital and the morbidities experienced during this time, duration of mechanic ventilation (MV), growth data up to their corrected age of 2 that consist of weight, height and head circumference. The growth data at birth and at discharge were evaluated with respect to the growth curves for premature infants by Fenton. The growth data were evaluated accordance with corrected age of the patients. The growth data for 40th gestation week-6th month, -12th month, -18th month and -24th month were evaluated with respect to the corrected growth percentile curves for Turkish children and Z-scoring system. The growth capturing month is said to have occurred when weight, height and head circumference with respect to the age is steadily -2 SDS and above. Statistical evaluations were performed by the following statistical tests: Shapiro-Wilk test and Mardia; (Dornik and Hansen Omnibus) test, Leneve test, Paired-Samples T test, General Linear Model-Repeated Anova (Bonferroni for Post Hoc analysis), Pearson Correlation and Spearsman's Rho test. Out of 77 cases with VLBW found in this study, 51% were male; 83% were AGA infant, 12% were SGA infant, and 5%were LGA infant. 79,2% of the cases that spent average 41,5±19,94 days as length of stay in neonatal intensive care unit were diagnosed with RDS; 7,8% with BPD; 26% with PDA; 44,2% with sepsis; 22% with NEK. 9% of the cases received steroid treatment for more than three days. Percentile averages of weight, height and head circumference of the cases at birth were significantly higher than those of measured at discharge (P<0,001). A significant positive relation was observed between weight, height and head circumference SDS values measured at 40th gestation week, 6th month, 12th month, 18th month, 24th month and weight and head circumference percentile values measured at discharge (P<0.005). A statistically negative relation was observed for the growth data between follow-up duration and discharge gestation week (P<0,05). A significant difference was not observed when the distribution of monthly SDS values of weight, height and head circumference were inspected with respect to the gender of cases (p=0.117). When SDS values of weight, height and head circumference were evaluated on a monthly basis, it was observed that SDS loss increased between 40th gestation week and 6th month, it reached to its lowest value at 6th month; SDS values increased afterwards. Even though 98,7% of VLBW infants achieved the growth in terms of weight, height and head circumference at the corrected age of 2, SD values were low for all three growth parameters. The proportion of achieving growth for head circumference was low when compared to those of weight and height measured at 40th gestation week, 6th month, 12th month, 18th month. It was found out that BPD, proven sepsis, RDS, steroid treatment for more than three days affect somatic growth. The effect of PDA and ibuprofen treatment on the head circumference was limited. There were no differences in data in terms of achieving the growth at the corrected age of 2 for AGA and SGA infants. However, the follow-ups of cases with SGA showed that the percentage of growth achievement of SGA infants were lower with statistical significance than that of AGA infants. In conclusion of this study, it was found appropriate that infants with VLBW and their growth parameters need to be monitored more carefully and frequently in the first six months; it is also necessary not to be late for appropriate nutrition and treatment support. Monitoring the head circumference proves to be an important parameter to follow both neuromotor development and somatic growth. The growth data, especially the head circumference parameter, need to be carefully monitored and the necessary supportive treatment need to be provided for the preterm infants when they are in neonatal intensive care unit since this treatment is effective on their growth at later ages. It is seen that BPD, proven sepsis, RDS, steroid treatment for more than three days, PDA and ibuprofen treatment affect somatic growth. The data reveals no difference in terms of achieving the growth at the corrected age of 2 for AGA and SGA infants; on the other hand, the percentage of growth achievement of SGA infants were lower than that of AGA infants. In order to have clearer inferences and to be able to make suggestions on this subject, there is a need to carry out research with a large population and aim to include long term results.