Food transition in premature newborn children: interfering factors

Purpose: to check the variables which interfere in the transition from the alternative way of feeding to the beginning of proper oral mode. Methods: 30 preterm newborns from a Neonatal Intensive Care Unit (NICU) partici-pated, with initial weight of 1,500 grams, interned between May and July 2018. The study of the medical records of babies was performed in relation to comorbidities such as length of stay, weight, gestational age, use of mechanical ventilation, as well as quantitative and correlational analysis of the data. Results: among the participants, 27 newborns began being fed in an orogastric man-ner and three, in a nasogastric way, and in some cases, artificial nipples were used. The average of gestational age coincided with the possibility of the proper via oral feeding. The longest time of transition was exactly with the newborns who had had clinical complications. Conclusion: the clinical complication interfered in the time and prevalence of the alternative way of feeding during the process of food transition which, associated with the use of artificial nipples, may have interfered in the early weaning and in the failure of exclusive breastfeeding.


INTRODUCTION
Feeding supplies all nutritional needs and promotes children's proper growth, as well as contributes to psychosocial development, state of alertness, cognition, motor development, neurological maturation, and mother-child interaction 1 . Some newborn children are considered at risk due to prematurity and low weight, and thus, they need an alternative way of feeding 2 .
Studies show that deglutition is mature around the eleventh week of pregnancy, suction around the thirty-second week, breathing and deglutition around the thirty-fourth week of pregnancy 3 . During suction the mandible movements, like opening, protrusion, closing, and retrusion are done. The coordination of these movements together with breathing and deglutition prevent children from choking, and thus avoids bronchoaspiration 4 . When there is not synchrony of these oral movements, other alterations associated to deglutition are identified, such as food refusal, fatigue, cough, oral escape, nasal regurgitation, cyanosis, and lung problems during breastfeeding 5 .
Many newborn children are born weeks before the expected development and therefore they need a long period until these functions are established and can be fed safely 6 . Prematurity can hamper newborn feeding because of the immaturity in deglutition's biomechanics. These functions facilitate the readiness for oral feeding when they are properly coordinated 7 .
The most used alternative methods of feeding premature newborn children in the service in study involve the nasogastric tube, orogastric tube, and the use of the cup. The cup technique allows an easy and safe feeding, being largely used in the practice until the infant has vigor and maturity necessary to breastfeeding. That technique is associated to a significant increase in the exclusive breastfeeding rates in the occasion of the rise, however, with a longer hospitalization period 8 .
The studies reveal that in clinical practice there is still difficulty in realizing the ideal moment for the beginning of transition from gastric feeding to oral way, being the height and gestational age some of the criteria of the transition. Most of the professionals do not evaluate specifically in a way that takes into account the aspects and conditions of the development with the oral motor skill 9 .
The speech therapist is the health professional who offers support to the mother-child dyad in the act of breastfeeding, especially in the Neonatal Intensive Care Unit (NICU). This professional contributes to the success of breastfeeding, helping with the correct position, handle, and milking. However, in order to do his job with quality, it is necessary to know the factors which interfere in the transition from the alternative way of feeding to breastfeeding.
Thus, the aim of this study was to analyze the variables which interfere in the transition from alternative way of feeding to the beginning of proper oral way in premature infants.

METHODS
The project was forwarded to the committee of Ethics This study was quantitative and correlational, whose population was constituted of pre-term newborn children, of both sexes, who were hospitalized in the Neonatal Intensive Care Unit (NICU) between May and July 2018.
This research was conducted in a Child Friendly Hospital which integrates the Health Care Network (HCN) of the area of coverage of the Regional Health Department DRS IX, being a reference to the attendance of 62 municipalities of the state of São Paulo, Brazil. The institution has service of medium and high complexity in the assistance to pregnant women and high-risk and vulnerable newborn children of the region, through the spontaneous demand or referrals of other institutions.
The Hospital offers multiprofessional attendance, composed of a Neonatologist, a Pediatrist, a Gynecologist, an Obstetrician, a Clinical Surgeon, a Nursing Team, a Physiotherapist, a Psychologist, a Social Worker, a Nutritionist, a Pharmacist, a Speech Therapist, besides students of Multiprofessional Residency.
As it is considered a Hospital which is part of Child-Friendly Hospital Iniciative (CFHI) of the Ministry of Health, in partnership with the United Nations International Children's Emergency Fund (UNICEF), the attendance is geared to breastfeeding and mothers pay visits in all schedules of feeding according to the medical prescription.
This research did not pose any risk to the participants' health, because its main aim was to identify in the medical records and daily notes during the period of hospitalization which could interfere in the transition from the alternative way of feeding to the beginning of the oral way, in a way that it could influence in the success of breastfeeding.
The criteria of inclusion established consisted of pre-term newborn children at gestational ages of 32 nd to 36 th weeks and six days; weight superior to 1,500 grams; good pattern of suction; good clinical stability; use of alternative way of feeding (orogastric or nasogastric tube) and hospitalized in NICU.
Newborn children who remained in NICU in serious conditions, at gestational ages higher than 37 weeks, weight inferior to 1,500 grams; neurological alterations, genetic syndromes/malformations, and infectious diseases which could make breastfeeding impossible were excluded of the research.
Based on the criteria listed above, 33 records were excluded, whereas two newborn children passed away, seven had weight inferior to 1,500 grams; 19 were born at fixed term, in other words, higher than 37 weeks of gestational age. Two of these were born with the Human Immunodeficiency Virus, one of them with Down Syndrome, and two of them with other Syndromes under investigation.
Initially, some newborn children were submitted to non-nutritious and nutritious speech therapy evaluation, while others did not go through this step, considering that the beginning of oral way was introduced by medical conduct or at days when there was no speech therapist, as, for instance, on weekends. In the evaluation, the following suction criteria were considered: state of consciousness of the newborn (alert, sleepy, excited); the oral reflexes (rooting, suck, bite, and gag reflexes); intraoral pressure, suctions per pauses, tongue cupping, cyanosis, and stress signs (cry, respiratory change).
During this period of hospitalization, the ingestion of exclusive and mixed (use of lactic formulas) breastfeeding by the use of cup or small sucking bottle was registered.
The documental analysis of the control sheet of the diets attached to each record was done, whose data were collected between May and July 2018, through the Appendix 1.
For the analysis of the data, the records were typed and stored in Microsoft Office Excel spreadsheet. For a better analysis of the variables, Table 1 was elaborated, in which the results about the duration/time (in number of days) of the transition from the diet by orogastric tube to the beginning of exclusive oral way were presented.

RESULTS
In the first stage, the records of 63 newborn children were analyzed. According to the criteria established, it was possible to analyze 30 records of pre-term newborn children, being 16 females and 14 males. The number of days of hospitalization of each child is shown in Figure 1.

Figure 1. Number of days of children's hospitalization
In newborn children with gestational age of 33 weeks, we observed more comorbidities, like, for instance, orotracheal intubation, use of non-invasive mechanic ventilation (CPAP) and longer stay in hospitalization, in other words, these factors interfered directly in the transition to the beginning of the oral way. The newborn children ate the ages of 35 and 36 weeks made use of only one day with the alternative way, which indicates that at this age there is actually maturation of the stomatognathic system and it fosters the beginning of the oral way.
The data collection was done every day during the hospitalization period. Of the correlated factors, we found gestational age, weight, orotracheal intubation, use of CPAP, orogastric and nasogastric tube, and time of hospitalization, that could interfere in feeding transition.
The shortest gestational age during this period was 32 weeks, the longest was 36 weeks and six days, the average being 35.972, approximately 36 weeks and two days.
Abbreviations NB= newborn GA= gestational age OTI= orotracheal intubation OGT= orogastric tube NGT= nasogastric tube that the beginning of the oral way in premature occurs around the 34 th week with maturation of deglutition. According to the pre-term newborn infants' weight, the lowest was 1,604g and the highest was 3,765g, with the average of 2,232g. Among them, 83% had weight loss before the beginning of the oral way, totaling 25 newborn children.
In premature infants with corrected chronologic age, it was possible to conclude that the beginning of oral way happened in around 6  Concerning clinical complications, there were newborn children who used non-invasive mechanical ventilation (CPAP) for a minimum of one day and maximum of five days. Those who needed orotracheal intubation stayed for at least one day and at most 15 days until the beginning of the oral way.
Of this group, 23 newborn children were submitted to the evaluation of non-nutritious suction (stimulus done with gloved finger in the oral cavity) before they began the feeding by oral way. One newborn infant was evaluated both in non-nutritious suction and in nutritious. One newborn infant was evaluated in nutritious and mother's breast. Two of them were evaluated directly in mother's breast. Of the total of 30 newborn children analyzed, only three initiated the diet directly by nasogastric way, going directly to the oral way, in other words, they did not go through any of the previous evaluations. It happened due to the fact that the newborn children may have initiated the oral way on weekends without the speech therapy evaluation or directly by medical conduct.
According to the results of this research, not all the newborn children went through all the stages of transition. Regarding breastfeeding, 19 newborn children received hospital discharge in free demand breastfeeding and 11 newborn children in mixed feeding with the use of small sucking bottle. Disregarding the first-time mothers and the ones who had a previous experience of breastfeeding, the use of nipple was kept because of the small volume of mother's milk production and also the neglect of the infant.

DISCUSSION
During this process of transition to oral way, some factors can interfere due to global immaturity 10 . Even if the criterion of gestational age is preconized in the liberation to the beginning of the oral way, this factor alone cannot be decisive 11 .
The population studied was of low-weight newborn children (average = 2,232 grams) with average of gestational age of 36 weeks and two days, coinciding with the possibility of adequate oral way. This could explain the high number of newborn children who had hospital discharge in breastfeeding. In the results we observed that the gestational age and the corrected age enabled the lesser time of stay with alternative way, reinforcing that at this age there really is the maturation of the stomatognathic system and fostering of the beginning of oral way.
Regarding the total time (in days) the results showed that the worst performance was exactly with the newborn children at gestational age of 33 weeks who had orotracheal intubation and needed to use the CPAP. Those ones had the need of using orogastric tube and prolonged nasogastric tube, and correspond to the longest period of stay of them. Besides, during the evaluation, these newborn children were in state of sleep, with partial response in rooting reflex, presence of bite reflex, weak intraoral pressure, absence of tongue cupping, pausable suctions, and respiratory alterations, in other words, they were inapt to the beginning of the oral way, which shows that the use of mechanical ventilation interferes in this transition.
Among the newborn children without complications, the average was of three and four days using the alternative way of feeding. Of this population, 90% began the feeding by orogastric tube, totaling 27 newborn children, whereas 14 of these successively began by exclusive oral way.
The adequate exclusive oral way corresponds to when the newborn infant is gaining weight, oral pattern with coordination of suction, deglutition, and respiration, although this maturation results in the infant gaining weight 12 , as well as the offer of breast in free demand, which may occur without complementation by cup/sucking bottle.
In the first days of life, the newborn children show a ponderal loss of weight, known as a physiologic factor. This evolution is considered as an indicator of adaptation of breastfeeding, the loss of weight being normal until 10% of the weight 13 . This piece of information justifies the high percentage (83%) which corresponds to 25 newborn children who had weight loss, with values that are expected and did not interfere in the transition to the oral way.
Many hospitals used the cup in their clinical practice, which is also considered an alternative way of feeding in the transition to the breast in order to avoid the use of bottles, due to the phenomenon of "confusion of nipples" 14 . The use of cups is recommended by the World Health Organization (WHO) for newborn children who are being breastfed. Being a safe method, it is used also with low-weight premature infants at birth, until they are mature enough to be exclusively breastfed 14 . When compared to the other ways of feeding, they were used to complement the newborn children who were already being breastfed due to hospital demand, however, its adherence is low, due to mothers' feeling of insecurity in keeping its use at home after discharge.
Regarding exclusive breastfeeding, the study showed that 19 newborn children had hospital discharge being breastfed in free demand, 11 children with mixed feeding and use of small sucking bottle, contributing to the precocious weaning. The Brazilian Regulation for Commercialization of Food for Infants and Young Children (NBCAL) corresponds to a set of laws that standardize the selling of food and products of childcare, and aims at guaranteeing for infants and children the right to breastfeeding. And by means of the law no. 11265/2006, selling nipples is prohibited, as well as their use, which causes precocious weaning 15 .
Breastfeeding brings several benefits which contribute to the whole growth and orofacial development, favoring the stomatognathic structures and functions of newborn children. However, the presence of the artificial nipple and certain medical behaviors contribute to the precocious weaning and the failure of exclusive breastfeeding.
Some factors are considered as decisive for newborn children to begin oral way feeding, being the maturation of suction primordial to the beginning of oral way. Thus, certain behaviors vary according to the medical team established in each institution. In general, and according to the literature, the corrected gestational age, weight, and clinical stability are the mostly used parameters by medical teams. Thus, the gain of weight is also relevant during the process of feeding transition, being considered one of the criteria adopted by medical doctors to the discharge of newborn children.

CONCLUSION
The results obtained through this study show that the clinical complications like orotracheal intubation and the use of CPAP interfered in the time of feeding transition from the alternative way to the oral one. Among the factors, the loss of weight did not directly show a significant relation to affect the transition to the oral way.