CUBAN MEDICAL LITERATURE

Abel Santamaría Cuadrado General Teaching Hospital, Pinar del Río

The Skin-to-Skin Method (Kangaroo Care):
Age Adjusted Evaluation
of Neuro-behavior at One Year

Dr. Ramón Acosta Díaz (1);
Dr. Carlos Enrique Piña Borrego (2);
Dr. Luis Ramón González (3);
Dr. Lucía López Fernández (4)

ABSTRACT: In order to evaluate neuro-behavior in premature babies during their first year of life with the Bayley test using the skin-to-skin method, 120 live births at the Abel Santamaría General Teaching Hospital in Pinar del Río were studied between January 1 and June 30, 2000 (study group). The control group included live premature infants born between July 1 and December 31, 2000 using the traditional method. Throughout the evaluation, using the Bayley test, a formula was used that gathered their clinical history, primarily of morbidity and perinatal asphyxia, as well as their nutritional regimen and neurological observation from 6 to 12 months of adjusted fetal age. A datebase was created in Microsoft Excel-2000; the Chi-Square table test was used with a confidence factor of p<0.05. Significant differences were observed in neuro-behavior between those premature infants who had the skin-to-skin method and those using the traditional method.

Keywords: PREMATURE/growth and development; NEUROLOGIC EXAMINATION/statistics and numeric data; NUTRITION; BREAST FEEDING; NUTRITIONAL CONDITION

Neurological development consists of the dynamic changes to the nervous system during development and growth. Neurological growth experiences rapid development between 29 and 40 weeks of gestational age. Therefore all agents that affect the fetus or newborn are very important in this first phase.[1]

The Graham method, one of the instruments used during the 1950's, was the first behavioral examination for the newborn using methods of behavior as part of a precise neurological examination; Graham's techniques included qualitative evaluations of tension and methods of motor responses, tactile responses, indices of irritability, ease with which the infant became calm and visual and auditory responses. Others such as Rosenblith, Parmelé, Scalón and Brazelton cited by Als,[2] created scales with more comprehensive evaluation of behavior in the newborn at term. The Ameil-Tisón[2] evaluation is able to differentiate between neurological depression and perinatal asphyxia as well as anticipating later results. We used Bayley[3] in this study because its mental and motor scales provide an easy, reliable and understandable evaluation of neurological organization and behavior in preterm infants and in their later years.

Inspired by the "kangaroo mother" methodology, since 1994 this institution has promoted skin-to-skin contact between mother and the newborn - independent of the seriousness of its condition - as it promotes a greater participation by the mother in attention to the preemie. The basic element of this method is the active participation of the mother by giving love and stimulation, and allowing the baby to breast feed whenever it wants. All this motivated research in which the neuro-behavior of the children using this method was evaluated using the Bayley test and comparing them with a control group with similar characteristics.

METHODS

An investigative, analytical, longitudinal and case-control study survey was carried out among 348 newborn premature infants born at the Justo Legón Padilla Maternity Hospital during 2000; 120 infants were selected from a stratified randomized group. Of these, 60 selected between January 1 and June 20 followed the skin-to-skin method, while the remaining 60, with identical criteria, were treated by the conventional method from July 1, 2000 to December 31, 2000. This was designed to evaluate the influence of the skin-to-skin method on neuro-behavior through age one using the Bayley test method. The formula for the survey gathered their clinical history from birth, including weight, height, gestational age, degree of intrauterine development, as well as neurological follow-up through one year of age in an exam (at 6 and 12 months) created specifically for that purpose. All data was collected in a computerized table. The mothers involved in the study took classes and participated in group meetings on the importance of breast feeding and infant stimulation, ending with their arrival at the "skin-to-skin" room. The care and stimulation of the child by its mother began from when they were admitted to the Neonatology Department, continuing as they were transferred to the skin-to-skin area; this generally occurred when their weight exceeded 1,500g, though this depended on, among other conditions, their sucking reflexes. Here, the mothers kept their children on their breast day and night, dressing in clothing especially adapted for this up to their release. At home, this process continued until both felt the bonding was complete.

Criteria for inclusion: 1. Newborn (NB) of 2,000g and gestational age under 37 weeks. 2. The mother's psychic and mental conditions were satisfactory. 3. Willingness of the mother to follow the skin-to-skin method (for the controls).

Bayley test: Applied to 6- and 12-month olds by a trained and licensed psychologist. Composed of two scales: mental and motor. This test showed a mode of conduct including the child's attitude toward its environment.

Statistical method: A database in Microsoft Excel-97 was developed to log the results using the Chi-square table (all the results are shown in individual tables), for the control and the study. The results, culled from that database, appear in the following tables, with a p<0.05 rate of confidence.

RESULTS

Table 1 shows the behavior of some independent variables in both groups such as: gestational age, birth weight, gender, degree of intrauterine development (IUD), use of a respirator and low Apgar score, in which there was no significant difference between the two groups despite the fact that the preemies had lower gestational ages than the controls (under 31 weeks 14/7), and that within the control group the males rated higher than the females (38/22) for a value of p=0.0665.

Table 1: Gestational Age, Weight, Gender, Use of a Respisrator, Apgar Score and Intrauterine Development in Both Groups

Abel Santamaría General Teaching Hospital, Pinar del Río: January 2000 - March 2002

Table 2 illustrates behavior of the Bayley test results in the motor scale according to the adjusted age, in which we see that in the low-normal category at 6 months, 5 of 57 in the group studied were affected, while in the control group, 12 of 51 evaluated showed significant differences (p=0.0199); it was among the children treated by the traditional method that came out highest in this category.

In the high-normal group, significant differences (p=0.0195) were seen between the children treated by the skin-to-skin method: 24 of 57 rated higher than those who followed the conventional method, with only 10 out of 51. For the mentally retarded, average and superior goups, no significant difference was noted between the groups. Similar results were seen at 12 months adjusted age.

Table 2: Bayley Test Results According to Adjusted Age: Motor Scale

Abel Santamara General University Hospital , Pinar del Río: January 2000 - March 2002

Source: Data Collection form Applied proof: Chi-square table (X í )

Table 3 reflects results of the Bayley test mental scale which shows that in the low-normal category for 6-month olds, 5 of 57 children in the study were affected, while in the control group, 13 of 51 were affected; significant differences were seen (p=0.0199). In the normal-high study, 23 of 57 children were affected, while 10 of 51 in the control study were affected (p=0.0195). In the average and superior categories, no significant differences were found with (0.3587) and (0.1907) respectively. However, the control study results prevailed. The same thing was seen at 12 months for corrected age.

Table 3: Bayley Test Results by Adjusted Age: Mental Scale

Abel Santamaría General Teaching Hospital, Pinar del Río: January 2000 - March 2002

Source: Date Collection form. Applied proof: Chi table (X " )

Table 4 represents the Bayley test results at 12 months of adjusted age according to critical morbidity at birth. Here we see that the mental scale for the low, normal and average showed scarcely any differences between children from the study group (19/12) and those in the control group (20/15), for a value of p=0.9273. Similar results were seen in the high (high normal-superior) categories, for a value of p=0.6381. The motor scale behavior was similar, and there were no significant differences between those who were ill and those who were not: p=0.7972 for the lowest scales and p=0.8450 for the high scales.

Table 4: Relation between the Bayley test Results at 12 months of Corrected Age and Neonatal Morbidity

Abel Santamaría General Teaching Hospital, Pinar del Río: January 2000 - March 2002

Source: Date Collection form. Applied proof: Chi table (X " )

Table 5 shows the Bayley test results at 12 months of adjusted age according to nutritional state, in which we look at the mental scale. The results show that in children below the 10th percentile, the lower categories look similar in both groups, while the children in the control group (6/1) were highest, although the differences were not significant (p=0.0621). In the case of children above the 10th percentile, the lower categories were similar in both groups, while the children in the control group (24/10) rated higher, and there were significant differences (p=0.0272). In the motor scale test, the results of children evaluated at less than the 10 th percentile in the lower categories were similar in both groups, while those in the high categories outperformed the others in the control groups (7/2), although there were no significant differences (p=0.1007). Results for children placed above the 10th percentile were similar in both groups in the lower categories and the children in the control groups were above those in the high categories (24/11), and there were significant differences (p=0.0451).

Table 5: Bayley Test Results According to Nutritional State at 12 Months Adjusted Age

Abel Santamaría General Teaching Hospital, Pinar del Río: January 2000 - March 2002

Source: Date Collection form. Applied proof: Chi table (X " )

DISCUSSION

In their series on premature children from 0 to 12 months who took the Brazy neurobiological test, Nunes and others[5] received samplings with similar characteristics for gestational age and birth weight. Other authors, such as Barrera and others[6], found similar results with application of the Denver test on underweight newborns up to 2 years of adjusted age. Use of a respirator at birth, the Apgar score under 5 min and the degree of intrauterine development, are important elements that should be considered in any research on neuro-behavior in premature children because of implications to the short- and long-term development of the central nervous system. Therefore we feel fairly certain that these characteristics showed similar results in both surveys.

The motor test evaluates elements such as muscular tone and its reflection in the structure of the body, mobility and muscular strength, deep tendon reflexes and responses by the soles of the feet, an indication of neurological soundness. Tests conducted during lactation tend to underscore that motor activities are fundamentally different at other ages where other indicators prevail. These results show the benefits of the skin-to-skin method. O'Hara and others[7] used the Denver Developmental Screening Test-II (DDST-II), and found better results for the motor scale in the group with early stimulation and multidisciplinary support at home. Sajaniemi and others[8] also reported similar results using the Infant Behavior Record, part of the Bayley scales.

Samsom[9] found better muscular response in the motor evaluation of high-risk premature infants during early lactation in children who were enrolled in programs of developmental support.

Feldman and others[10] found that children enrolled in premature intervention programs had better cognitive development than other groups. Gomes[11] also observed that mental development in premature babies that received auto-motor sensory stimulation was quicker and necessitated shorter hospital stays when compared to children treated by traditional methods. Francois[12] also observed that even premature babies with multiple risk factors (antenatal, perinatal and socio-economic), had improved mental scores when they received appropriate and early stimulation. In his series, the children were studied through 42 months of age. The results of this work wholly concur with the medical literature consulted.

Critical morbidity at birth acts in synergy with the appearance of developmental results (serious handicaps, sensory changes and minimum cerebral dysfunction). Liley and Stark[13], for example, stated that 10% to 15% of premature babies who survived serious respiratory distress syndrome had long-term neurological deterioration. Using the Bayley scales for infant development, Perad and Berger[14] linked chronic lung disease in premature babies to retarded development of motor coordination and deteriorated visual perception. Fischer and others[15] found that there is better cardio-respiratory stability for children using the kangaroo care method as it reduced the damaging effects of critical morbidity to the central nervous system. In his work, Brietbach[16] found that one advantage of this method is reduced respiratory distress and apnea, increased concentration of arterial oxygen, lower bradycardia episodes and shortened hospital stays. All of this contributes to minimizing the long-term negative neurological effects. The results of this study do not coincide with the referenced medical literature since we did not observe that the skin-to-skin method influenced neuro-behavior in children with critical morbidity at birth. This could well be related to the size of the study, the brief period during which the study was conducted and the fact that the Cuban health system has prioritized primary care for premature infants.

There is no doubt that nutritional state proportionally impacts neuro-development. Proper nutrition allows the body to assimilate the essential nutrients needed for good cellular functions. All premature newborns are at nutritional risk because of: 1. Scarce nutritional deposits; 2. Better growth indices by utilizing nutrients faster; 3. Immature physiological systems; and 4. Incomplete knowledge of required nutrients. The Central Nervous System cannot avoid this. In this study, one may observe the positive influence the skin-to-skin method had on neuro-behavior and nutritional state. A study by Van Staveran and Dagnelie[17] found that well-nourished children given the early stimulation method had higher intelligence coefficients; however, this method produced no results in poorly nourished children. Pinelli and others[18] stated that adequate nutritional support in premature babies with low birth weights helps the development of higher intelligence levels, especially among children enrolled in development support programs. Larquiar and others[19] also found better neuro-behavior in very low birth weight newborns given adequate nutrition and early development support.

REFERENCES

1. Domínguez F. Neurodesarrollo y estimulacíon temprana. En: Sola A. Rogido M, Cuidados especiales del feto y del recién nacido . 2a ed, vol 1. Buenos Aires: Marcelo T. De Alvear Interamericana; 2001:1705-19.
2. Fanaroff AA, Poland RL, Baver CB, Tyson JE."At Risk For Infection: The VLBW Infant." J Perinat Neonatal News 1998; 7(4):52-64.
3. Bayley N. Bayley Scales of Infant Development . New York : The Psychological Corp; 1969.
4. Acosta C, Picon C. Asistencia maternal permanente en "Contacto piel a piel" Programa "ANAF". En: Sola A, Rogido M. Cuidados especiales del feto y el recién nacido . 2a ed., vol 1. Buenos Aires: Marcelo T. De Alvear Interamericana; 2001: 281-5.
5. Nunes A, Mello F, Sina JE, Costa A, Bispo MA, Palmila JM. "Importancia do índice neurológico de J. Brazy. Prediccao do numero e gravidade de secuelas dos recem nascido do muito baivo peso". Acta Med Port 1998; 11(7):615-21
6. Barreras J, Hernández F, Guerra A. "Alteraciones del neurodesarrollo en recién nacidos de muy bajo peso al nacer hasta el Segundo ano de edad corregida." En: Pediatría 2001, Programas y Resúmenes. La Habana: Palacio de las Convenciones; 2001:309.
7. O'Hara MT, Church CC, Blatt SD. "Home-based developmental screening of children in foster care". Pediatr Nurs 1998; 24(2):113-7.
8. Sajaniemi N, Solokorpi T, Von Wendt L. "Temperament Profiles and Their Role in Neurodevelopmental Preterm Children at Two Years of Age." Eur Child Adolesc Psychiatry 1998; 7(3):145-52.
9. Samsom JF, de Groot L, Hopkins B. "Muscle Power and Medical History in High Risk Preterm Infants at 3 Months at Corrected Age." Neuropediatrics 1998;29(3):127-32.
10. Feldman R, Eidelman AI. "Intervention Programs for Premature Infants. How and Do They Affect Development?" Clin Perinatol 1998; 25(3):613-26.
11. Gómes CF. "Estudo comparativo da relacao entre stimulacao oromotossensória e alta hospitalar precoce em recém nacidos de risco.' Temas Desenvolv 1999; 8(46):15-9.
12. Francois A, Battisti O, Bertrand JM, Lalenga P, Langhendries JP. "Bebe premature, bebe particulier? Quel suivi developmental?" Arch Pediatr 1998; 5(5):568-72.
13. Liley HG, Stark AR. "Respiratory Distress Syndrome. Hyaline Membrane Disease." In: Cloherty JP, Stark AR. Manual of Neonatal Care . 4 th ed. New York : Lippincott Williams and Wilkins; 1998:329-36.
14. Parad RB, Berger RM. "Chronic Lung Disease." In: Cloherty JP, Stark AR. Manual of Neonatal Care . 4 th ed. New York : Lippincott Williams and Wilkins; 1998:378-87.
15. Fisher CB, Sontheimer D, Scheffer F, Baver J, Linderkamp O. "Cardiorespiratory Stability of Premature Boys and Girls during Kangaroo Care." Early Hom Dev 1998: 52(2):145-53.
16. Brietbach K. "What is Kangaroo Care?" Arch Pediatr Adolesc Med 2001; 155(5):543-4.
17. Van Staveran WA, Dagnelie PC. "Food consumption, growth and development of Dutch children fed on alternative diets." Am J Clin Nutr 1988;48:819.
18. Pinelli J, Atkinson SA, Saigal S. "Randomized trial of breast feeding support in very low-birth-weight infants." Arch Pediatr Adolesc Med 2001;155(5):543-4.
19. Larquia A, Miguel P. "Evaluación ponderal en recién nacidos de muy bajo peso al nacer con alimentación enteral precoz y progresiva." Pediatr 1997;95(4):234-41.

THE AUTHORS

1. Dr. Ramón Acosta Díaz is a Second Degree Specialist in Pediatrics, on the faculty of Medical Sciences in Pinar del Río and head of the Neonatal Department at the Abel Santamaría Cuadrado General Teaching Hospital in Pinar del Río.
2. Contact: Edificio Gran Panel No. 102, Apto. D-3, Carretera de Borrego, Reparto Hermanos Cruz, Pinar del Río, Cuba;
   E-mail racosta@princesa.pri.sld.cu.
3. Dr. Carlos Enrique Piña Borrego is a third year neonatal resident at the Abel Santamaría Cuadrado General University Hospital, in Pinar del Río.
4. Dr. Luis Ramón González is a resident at the Abel Santamaría Cuadrado General Teaching Hospital in Pinar del Río.
5. Dr. Lucía López Fernández is a First Degree Specialist in Neonatology at the Abel Santamaría Cuadrado General Teaching Hospital in Pinar del Río.