Influence of modern principles of feeding on osteopenia in premature newborns in the neonatal period



Relevance: according to domestic and foreign studies, one of the leading places in prenatal morbidity and mortality is occupied by preterm delivery [1, 4]. The clinical prognosis improves both with an increase in gestational age and with an increase in body weight at birth. The birth of children before the 32nd week of pregnancy maintains a high level of morbidity and mortality [2, 7].

Premature babies are at a higher risk of impaired development of the nervous and respiratory systems, the gastrointestinal tract, and metabolic disorders. The overall incidence is observed in 60 % of children born at the 26th week of pregnancy, and in 30 % of children born at the 31st week [3, 5].

According to many authors, newborns born with extremely low and very low body weight have diseases that are not characteristic of full-term newborns with normal body weight. One of the representatives of these diseases is osteopenia in premature newborns. In the etiology and development of this disease, in addition to the pathophysiological mechanisms that are typical to extreme immaturity of the body, iatrogenic influences of the established practice of treatment and nutrition of premature babies in Russian neonatology are of great importance [6, 9].

Thus, in the context of an increase in the population of children born prematurely and the accumulation of experience in the survival of newborns in this category, it dictates the need for mandatory prevention of diseases typical of immaturity. Prevention and treatment of electrolyte disturbances in the form of osteopenia in extremely immature children requires optimization of feeding methods.

Objective: to study the clinical relationship between the occurrence of osteopenia in premature infants, depending on the principles of feeding.

Material and methods: the basis of this study is the results of a dynamic examination of 45 premature infants. The gestation period was 28–36 weeks. Birth weight ranged from 744 to 2230 grams (average weight 1469.3 ± 235.8 g.).

To achieve this goal, all premature infants were divided into 3 groups depending on the feeding:

Group 1 consisted of 14 premature infants who were breastfed with the inclusion of specialized mixtures;

Group 2 consisted of 16 premature infants who were only breastfed with milk fortifiers “PreNANFM 85”.

PreNAN® FM 85 is a hypoallergenic breast milk fortifier that promotes the growth of premature and small babies. («Nestle», Germany), representing dry powder in 1 g sachets, which is diluted in 20 ml of breast milk. The fortifier contains a deeply hydrolyzed 100 % whey protein with an amino acid profile that repeats the profile of breast milk, a 100 % glucose polymer that provides high energy density and low osmolarity, a vitamin-mineral complex to fill the needs of premature babies with low and extremely low body weight at birth. Through the use of OGM, 84.5 kcal, 10.6 g of carbohydrates, 99.9 mg of calcium, 59.5 mg of phosphorus, as well as a whole complex of vitamins and minerals are provided (in terms of 100 ml of breast milk). Maltodextrin was used as a source of carbohydrates in ORE “PRE NAN FM 85”, which reduces the lactase load and improves digestion. Also, when OGM is added, the energy value of breast milk increases significantly — up to 140–150 kcal / kg / day.

Group 3 consisted of 15 premature infants who are breastfed with artificial mixtures.

Among 10 children of the 1st clinical group there were 7 (50 %) girls and 7 (50 %) boys. The average gestational age of children in this group was 30.4 ± 2.6 weeks.

Of the 16 children of the 2nd clinical group, there were 10 (62.5 %) boys and 6 (37.5 %) girls. The average gestational age of children in this group was 28.6 ± 2.1 weeks.

Among 15 children of the 3rd clinical group there were 11 (73.3 %) girls and 4 (26.7 %) boys. The average gestational age was 31.8 ± 3.1 weeks.

The study was conducted while the premature babies were in the neonatal pathology unit at the Republican Perinatal Center.

Laboratory signs of osteopenia are low levels of serum phosphorus, high levels of alkaline phosphatase, as well as hypercalcemia and hypercalciuria, which accompany an insufficient intake of phosphorus. The lower limit of serum phosphorus in preterm infants is often taken to be 1.3 mmol / L.

All the newborns examined had a level of total calcium, phosphorus in the blood plasma by the biochemical method.

During the statistical processing of the results, parametric and nonparametric indicators were differentiated using the Student test and the Mann-Whitney test. With a difference between the results equal to p <0.05, a static result was valid.

Results of the study: in the process of monitoring children of all groups, good tolerance of the prescribed nutrition was noted. However, moderate bloating in 50 % of children who received breast milk with OGM, which did not affect the well-being of children, was not accompanied by a noticeable decrease in stool frequency or constipation. A tendency to constipation and a decrease in stool frequency was observed in 50 % of children who were fed breast milk in combination with a mixture for premature babies (Table 1)

Table 1

Clinical evaluation of the effectiveness of various types of feeding

Index	1st group(n=14)	2nd group (n=16)	3rd group (n=15)
Birth weight, g	1502±314,4	1480±263,6	1426±324,5
Daily weight gain, g	25,6±3,7	35,3±6,6	20,9±2,6^
The number of regurgitation per day	3,7±0,6	2,8±0,4	2,5±0,5*
Presence of intestinal colic, %	11 (78,6 %)	10 (62,5 %)	11 (73,3 %)
Stool frequency	2,3±0,2	3,2±0,3	3,5±0,3*
Constipation	6 (42,9 %)	5 (31,3 %)	3 (18,8 %)*
Duration of hospitalization, bed days	30,9±10,1	27,4±7,0	29,8±9,2

Note: * — the reliability of the data for the 1^st group (Р≤,05); ^ — the reliability of the data for the 2^nd group (Р≤,05)

Daily weight gain in children of the 2nd group was higher than in the 3rd group of children, and significantly higher compared to the 1st group of children. The worst tolerance of enteral nutrition was observed in children of the 1st group, which was estimated by the number of regurgitation and intestinal colic per day, and this allows us to give preference to breastfeeding with the addition of OHM. The length of hospital stay in children of the studied groups differed in favor of children of the 2nd group, which was expressed in a shorter stay in the hospital, ceteris paribus.

Premature babies need to be provided with adequate intake of minerals and vitamins, in particular calcium, phosphorus and vitamin D. Given that 90–150 mg / kg / day of calcium is delivered to the fetus, and calcium absorption in the intestines of newborns occurs by 50–80 % (on average 60–65 %), the need for calcium during enteral nutrition in premature infants is 120–200 mg / kg / day [4, 6]. The best ratio of calcium to phosphorus by mass is considered to be 1.7–2: 1. In accordance with this, and taking into account the absorption of phosphorus in the intestine by 80–90 %, a premature baby needs an enteral intake of about 90 mg / kg / day of phosphorus [1, 6].

As a result of the studies, it was found that in premature infants, the total level of calcium tended to decrease in relation to the reference values ​​(2.21 ± 0.56 mmol / l). The lowest level of calcium (1.5 ± 0.05 mmol / l) in the neonatal period was observed in morphofunctionally immature children of the 3rd group (Table 2).

Table 2

Laboratory evaluation of the effectiveness of various types of feeding, (M±m)

Index	1st group	2nd group	3rd group
Ca, mmol/L	1,76±0,01	2,11±0,02*	1,56±0,05^
P, mmol/L	0,89±0,05	0,96±0,05*	0,77±04^

Note: * — the reliability of the data for the 1^st group (Р≤,05); ^ — the reliability of the data for the 2^nd group (Р≤,05)

Despite the therapeutic measures taken, in premature infants of both groups, the total calcium level remained low in children of groups 1 and 3. However, in children of group 2, the Ca2+ indicator reached reference values.

Phosphorus, which is the main material in the formation of bone tissue, is subject to various changes (table. 2). The level of phosphorus in the blood serum of children in all groups was low compared to the reference values (0.89 ± 0.05, 0.96 ± 0.12, and 0.77 ± 0.4 mmol / L, respectively).

Thus, plasma hypocalcemia is accompanied by hypophosphatemia. Impaired metabolism of calcium and phosphorus, which play a major role in the formation of bone tissue — osteogenesis, has led to serious changes in the hormones that regulate this metabolism.

Conclusion: in the process of monitoring children of all groups, good tolerance of the prescribed nutrition was noted. However, moderate bloating in 50 % of children who received breast milk with OGM, which did not affect the well-being of children, was not accompanied by a noticeable decrease in stool frequency or constipation. A tendency to constipation and a decrease in stool frequency was observed in 50 % of children who were fed breast milk in combination with a mixture for premature babies. Daily weight gain in children of the 2nd group was higher than in the 3rd group of children, and significantly higher compared to the 1st group of children. The worst tolerance of enteral nutrition was observed in children of the 1st group, which was estimated by the number of regurgitation and intestinal colic per day, and this allows us to give preference to breastfeeding with the addition of OHM. The length of hospital stay in children of the studied groups differed in favor of children of the 2nd group, which was expressed in a shorter stay in the hospital, ceteris paribus. When using OGM for feeding premature babies, the following advantages were revealed over feeding only breast milk or breast milk in combination with a mixture for premature infants:

– The benefits of breastfeeding remain;

– higher intensity of weight gain;

– reduction in the length of hospital stay;

– good tolerance;

– elimination of the imbalance of Ca and P in premature infants

– prevention of osteopenia.

– high levels of Ca and P in serum in preterm infants receiving breast milk fortifiers.

All of the listed advantages of feeding premature babies with breast milk (if there is enough) with the addition of OHM allow us to recommend enrichment for widespread use.

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