Fecal calprotectin concentrations in premature infants have a lower limit and show postnatal and gestational age dependence.

BACKGROUND: There is a need for reliable diagnostic biomarkers in necrotizing enterocolitis (NEC). Whereas fecal calprotectin (fCP) has been reported to have insufficient sensitivity and specificity, no previous study has stratified for gestational and postnatal age. OBJECTIVE: We aimed to provide developmental specific fCP data in premature infants and to analyze its value in detecting intestinal distress and episodes of NEC. METHODS: Between April 2008 and December 2009, 1,899 fecal samples were obtained from 206 very low birth weight infants. RESULTS: Mean gestational age (GA) was 28.5 weeks and birth weight 1,057 g. 19 (9.2%) patients developed NEC stage II+, of whom 5 had fulminant NEC with unusually low fCP concentrations in meconium and afterwards. fCP levels showed significant gestational and postnatal age dependent dynamics with particularly low levels in extremely premature infants. In infants with a GA <26 + 1 weeks using GA-adapted reference values, the sensitivity for discriminating moderate NEC from healthy infants and infants with intestinal distress was 0.89 for a cut-off of 180 and 210 µg/g, respectively, at onset of symptoms. Specificity was 0.96 and 0.84. Fulminant NEC was characterized by unusually low fCP concentrations with a cut-off of <24 µg/g having a sensitivity of 0.84 and a specificity of 0.72 for identifying those cases. CONCLUSIONS: fCP levels depend on gestational and postnatal age and in contrast to adults, there is a lower limit in premature infants. Taking these observations into account when defining reference values and interpreting fCP data in the clinical context, fCP can be a useful marker in identifying premature infants with gastrointestinal distress and NEC in particular.

Mortality and major morbidity in premature infants less than 31 weeks gestational age in the decade after introduction of surfactant.

OBJECTIVE: Population- but also center-based mortality and major morbidity rates of premature infants are essential for prenatal counseling and quality control. METHODS: Records of all infants <30 + 6 weeks (n=674) admitted (1991-2000) to a single neonatal intensive care unit were reviewed and compared to the state-wide mortality. RESULTS: Six hundred and ninety-one infants were born in or transferred to the hospital and 600 infants (89%) survived. The mean (SD) birth weight was 1018 g (+/-314) and the mean gestational age 27+5 weeks (+/-2.0). Mortalityand morbidity did not change significantly over the 10-year period but correlated inversely with gestational age from 45% at 23(0/7) weeks to 5% at 30(6/7) weeks. Study center mortality rate for extremely low birth weight infants with birth weight <750 g was significantly lower than reported for the entire state (local 25%; Bavaria 36% p = 0.0003). Thirty-four per cent (251/600) of the survivors had one or more major complications: intracranial hemorrhage III-IV 8% (88/600), periventricular leucomalacia 6% (41/600), bronchopulmonary dysplasia with oxygen requirement at 36 weeks 20% (128/600), necrotizing enterocolitis 6% (43/600), and retinopathy of prematurity grade III-IV 9% (55/600). Survival without major morbidity increased from 32% at 23 weeks to 92% at 30 weeks. CONCLUSIONS: Despite changes in obstetric and neonatal care during the 1990s, mortality and major morbidity rates did not change significantly after the introduction of surfactant in 1991. Comparison of local, regional, national, and international mortality and morbidity rates are becoming more important in allocating resources and in decision-making at the limits of viability.

Postnatal growth curves for extremely low birth weight infants with early enteral nutrition.

UNLABELLED: Early enteral nutrition improves growth of extremely low birth weight infants, but growth curves beyond 30 days of life are lacking for such infants receiving early enteral nutrition. Based on the data of all infants born in a 4-year interval with a birth weight <1000 g and surviving for >56 days, we calculated growth rates and weight gain over 120 postnatal days. Infants with major congenital anomalies or necrotising enterocolitis were excluded. Daily weight, weekly length, head circumference and nutritional data were collected until discharge or for maximal 120 days. Curves were calculated in 100 g birth weight intervals, and separately for appropriate for gestational age (AGA) and small for gestational age (SGA) infants. Data were available from 163 infants (birth weight 768 g +/- 153 g; gestational age 26.8+/-1.8 weeks; mean +/- SD) including 55 SGA infants (33.7%). Full enteral feeding was achieved at day 21.7 (+/-10.4). After 12.8% (+/-6.6%) maximal postnatal weight loss at day 7.5 (+/-3.0), birth weight was regained at 14.6 (+/-6.0) days. Mean overall weight gain was 15 g/kg per day with a significantly higher weight gain for SGA than for AGA infants (P <0.05). CONCLUSION: Our early fed infants achieved better weight gain than those recently published receiving late enteral nutrition, but nevertheless fell below the 10th percentile of intrauterine curves. Which postnatal growth is ideal for extremely low birth weight infants infants is unclear. Our growth curves should not be taken as reference curves of a "normal population" but may help to identify infants with growth failure.