Reduced postnatal growth in very low birth weight newborns with GE ≤ 32 weeks in Spain

Aim: To analyze postnatal growth restriction in a cohort of very low birth weight (VLBW) infants with gestational age ≤ 32 weeks in 55 Spanish neonatal units (SEN 1500 Network) during 2002 and 2003. Methods: Weight, length and head circumference were recorded at birth, and at discharge. Weight was also recorded at 28 days postnatal, and 36 weeks of postmenstrual age. Growth restriction was measured as the shift in weight z score from birth to 28th day. Results: The study included 2317 VLBW infants. Weight z score at birth, 28 days, 36 weeks of postmenstrual age and discharge were: -0.66 ± 1.3, -2.54 ± 1.35, -3.12 ± 1.7, -1.56 ± 1.1, respectively. Length z score at birth and at discharge were: -0.88 ± 1.8, and -1.97 ± 1.56. Head circumference z score at birth and at discharge: -0.83 ± 1.87, and -0.60 ± 1.96. Prenatal steroids, gestational age, place of birth, type of hospital, CRIB score, symptomatic patent ductus arteriosus and late-onset bacterial sepsis were related with the shift in weight z score at 28 days (multiple linear regression), but explained very little (14%) of his change. Weight and length at discharge were under the 10th percentile in 77% and 80% of the infants, respectively. Conclusions: VLBW infants ≤ 32 GA suffer postnatal growth restriction with respect to intrauterine growth pattern, which is more relevant in the first 28 days of life, in patients with more severe illnesses, and differs among neonatal units. Perinatal and neonatal items evaluated are poorly related with restriction.