Bone status in preterm infant: influences of different nutritional regimens and possible markers of bone disease

Bone Status and Early Nutrition in Preterm Newborns with and without Intrauterine Growth Restriction

Intrauterine growth restriction (IUGR) together with preterm birth could be harmful to bone health. The aim of the study was to examine bone status in IUGR versus non-IUGR preterms and to analyze the nutritional management best correlated with its improvement. Newborns < 34 weeks of gestational age (wGA), 75 IUGR and 75 non-IUGR, admitted to the Neonatal Intensive Care Unit of the University Hospital of Padova were enrolled and monitored from birth until 36 wGA through anthropometry (weight, length, head circumference, lower limb length (LLL)), biochemistry, bone quantitative ultrasound assessment of bone status (metacarpus bone transmission time, mc-BTT, us) and nutritional intakes monitoring during parenteral nutrition. IUGR compared to non-IUGR showed lower mean mc-BTT (0.45 vs. 0.51, p = 0.0005) and plasmatic phosphate (1.45 vs. 1.79, p < 0.001) at birth. Mc-BTT at 36 wGA, though equal between groups, correlated in IUGR newborns with basal phosphate, mean total energy of the first week and month (positively) and days to reach full enteral feeding (negatively). Lower i.v. vitamin D intake, LLL and prolonged total parenteral nutrition predicted worse mc-BTT at 36 wGA in the enrolled infants. These results suggest that preterms and in particular IUGR newborns need special nutritional care to promote bone development.

Providing the Best Parenteral Nutrition before and after Surgery for NEC: Macro and Micronutrients Intakes

Necrotizing enterocolitis (NEC) is the main gastrointestinal emergency of preterm infants for whom bowel rest and parenteral nutrition (PN) is essential. Despite the improvements in neonatal care, the incidence of NEC remains high (11% in preterm newborns with a birth weight <1500 g) and up to 20−50% of cases still require surgery. In this narrative review, we report how to optimize PN in severe NEC requiring surgery. PN should begin as soon as possible in the acute phase: close fluid monitoring is advocated to maintain volemia, however fluid overload and electrolytes abnormalities should be prevented. Macronutrients intake (protein, glucose, and lipids) should be adequately guaranteed and is essential in each phase of the disease. Composite lipid emulsion should be the first choice to reduce the risk of parenteral nutrition associated liver disease (PNALD). Vitamin and trace elements deficiency or overload are frequent in long-term PN, therefore careful monitoring should be planned starting from the recovery phase to adjust their parenteral intake. Neonatologists must be aware of the role of nutrition especially in patients requiring long-term PN to sustain growth, limiting possible adverse effects and long-term deficiencies.

Diet in pregnant women that delivered prematurely and preterm newborn's bone status

OBJECTIVES

Inadequate maternal dietary pattern has been associated to negative pregnancy and fetal outcomes. With this study, we aimed to evaluate the adequacy of diet in pregnant women that delivered prematurely and its possible correlations with bone status of preterm newborns.

STUDY DESIGN

We prospectively enrolled women who delivered prematurely (≤than 34 gestational weeks) and their newborns (Neonatal Intensive Care, University Hospital of Padova) from January 2017 to May 2018. Maternal nutritional status and diet supplementations were assessed using a validated questionnaire. The preterm newborns were evaluated with anthropometric measurements and bone status by Quantitative Ultrasound of the second metacarpal bone within 72 h from birth.

RESULTS

One hundred and eighty mothers and 202 preterm newborns were evaluated. The mothers assumed more calories, proteins, total lipids and simple sugars compared to the revised National Guidelines. The intake of calcium, phosphorus and Vitamin D was inadequate despite the use of multivitamin supplements. The mothers assumption of vitamin D and zinc positively correlated with bone status and mothers with very low intake of vitamin D during gestation (<7 µg/die) had preterm newborns with a worst bone status at birth compared to those with a better intake (>7 µg/die).

CONCLUSIONS

Nutrition of pregnant women could be improved and maternal intakes of Vitamin D and zinc positively correlated with preterm newborn's bone status.

Risk factors of bone mineral metabolic disorders

Bone remodeling is a complex process which integrates different stimuli factors such as mechanical, nutritional and hormonal factors as well as cytokines and growth factors. Bone health depends on an adequate balance between all these factors. The typical bone pathology of the newborn is the metabolic bone disease of prematurity, favored by a lack of mineral accretion in the third trimester of gestation. The intrinsic defects of the bone tissue (primary osteoporosis) are usually of genetic or idiopathic origin and can affect both the term and the preterm newborn. Other risk factors for osteopenia (secondary osteoporosis) include maternal or gestational factors, nutritional deficits (calcium, phosphorus, vitamin D), endocrinological alterations, use of certain medications antagonistic to bone metabolism, mechanical factors and chronic diseases (renal or hepatic insufficiency, intestinal malabsorption, collagen or metabolic diseases). This review examines the risk factors of developing bone metabolic disorders in neonates.

Incidence of metabolic bone disease in preterm infants of birth weight <1250 g and in those suffering from bronchopulmonary dysplasia

BACKGROUND & AIMS

Preterm infants are exposed to a higher risk of developing Metabolic Bone Disease (MBD) with an increased bone fragility, a higher fracture risk and a long-term reduced linear growth and childhood height. Monitoring bone growth has become mandatory in neonatology. Several risk factors have been identified among the population of extremely low birth weight infants, but we still do not know which is the real incidence of MBD since its evaluation is not routinely performed worldwide. The aim of this study was to evaluate the incidence of MBD in preterm infants and in those suffering from bronchopulmonary dysplasia (BPD).

METHODS

Prospective evaluation of patients who developed BPD (BPD group) versus infants who did not develop it (no-BPD group). We examined, in preterms <1.250 g, the metacarpus bone transmission time (mc-BTT) at birth, 21 days and 36 weeks of gestational age (GA) together with biochemical markers of bone status.

RESULTS

We included 135 patients, 55 with BPD. BPD patients received less total proteins in the first two weeks and less energy in the first month of life (p = 0.007 and p < 0.001 respectively). BPD patients had a worse growth velocity at two weeks of age (12.36 ± 7.86 vs 16.59 ± 7.05 g/kg/day, p = 0.001). At 21 days, BPD patients had lower phosphatemia (1.65 ± 0.031 mmol/L vs 1.85 ± 0.034 mmol/L, p = 0.007) and higher alkaline phosphatase levels (411.62 ± 135.31 IU/l vs 338.98 ± 102.20 IU/l, p = 0.005). BPD patients had significantly worse mc-BTT at 36 weeks GA (0.45 ± 0.06 vs 0.50 ± 0.08 μsec, p < 0.001) and a higher incidence of MBD (60% vs 34%; p = 0.012).

CONCLUSIONS

BPD infants are a special subset of patients among preterms who receive, in the first month of life, a lower energy intake than patients without BPD. BPD patients have a suboptimal bone growth and a higher incidence of MBD. Monitoring growth, bone status and optimizing nutritional intakes need to be further improved in preterm infants with BPD.