5th Congress Autism-Europe
Articulos / Proceeding
Autism-Spain

PRE-, PERI- AND POSTNATAL RISK FACTORS IN AUTISTIC CHILDREN

INTRODUCTION

Autism is a disorder of early childhood of unknown etiology described symptomatically, and numerous authors agree that it is a multicausal disorder. Clinical picture according to DSM-III-R (1987) includes three groups of symptoms: impairment in social interaction, impairment in verbal and nonverbal communication and restricted repertoire of activities and interests. Autistic examinees have been compared to healthy children, mentally retarded, psychotic and their non-autistic siblings to investigate risk factors. Various studies point to possible different risk factors. From prenatal factors there have been singled out bleeding during pregnancy and taking of medicines in pregnancy. Peripartal complications as for example breech presentation and meconial amniotic fluid, have been mentioned as low birth weight, low APGAR score, haemolytic diseases, respiratory distress and high fever. Gillberg and Gillberg (1983) were first to apply the concept of optimality, and they mention statistically significantly decreased optimal pre-, peri-, and neonatal conditions and total scores in autistic as respect to controls. Harper and Williams (1975) have studied the time of beginning and type of autistic behavior, and have found that prenatal and perinatal risk variables in greater part are connected with an early start and worse prognosis. Mason-Brothers et al. (1990) have not found differences between pre-, peri and postnatal factors among autistic examinees and their healthy siblings, and consider genetic influence essential. In Croatia up to date have been published two studies about risk factors in autistic children (Kocijan et al., 1991. and Bujas-Petkovic 1993) in which bleeding during the pregnancy was pointed out.

SUBJECTS AND METHODS

The examined sample is 100 autistic examinees (75 male and 25 female) in the age from 3 to 20 years of different intellectual functioning and control groups 100 mentally retarded examinees according to sex, age and mental functioning, and a group of 100 healthy children of preschool age (75 boys and 25 girls) by random choice in several kindergartens. The diagnosis of autism has been established at the Department for Autism of Psychiatric Hospital Jankomir in Zagreb, according to criteria DSM-III-R (1987). From the control group of mentally retarded group the children with known etiology have been excluded (e.g. genetic abnormalities, as for example Down sy., phenilketonuria, etc.). The data for research were obtained from specially composed questionnaire filled out by parents, which included -apart from the general information (age and sex of the child, intellectual functioning, parental age at the time of birth, parents degree of education) -, the information about A) diseases of mother, father, brothers and sisters and closer family (psychosis, neurosis and alcoholism, epilepsy, mental retardation), B) information about pregnancy (spontaneous abortion, maternal age, chronic disease of the mother, bacterial and viral infectious, medicine taking during gestation, bleeding, anaemia, vomiting, smoking, multiple pregnancy, births weigh), C) information about delivery (termination, duration, presentation, umbilical cord around neck, cry) and D) information about postnatal development. Results were obtained by hisquare test and risk factors from previous groups were tested by Kruskal-Wallis test as new variables: disorders in the family, risk factors before the childbirth, risk factors during the birth, and risk factors after the delivery.

RESULTS

Disorders in the family (genetic factors)

Legend for tables 1,2,3. Numbers in columns are observed frequency, percentage for rows, percentage for columns and total percentage.

Table 1. Disorders of the mother

Hi-square 0,03922; d.f. 1; p 0,8430.

Table 2. Disorders of the father

Hi-square 10,01021; d.f 2; p 0,0067

Table 3. Disorders of the siblings

Hi-square 0,93050; d.f 1; p 0,3347

Prenatal risk factors

Legend for tables 4 and 5. Numbers in columns are observed frequency, percentage for rows, percentage for columns, total percentage, frequencies difference, and contribution of the category.

Table 4. Spontaneous abortions of the mother

Hi-square 1,38527; d.f 4; p 0,8468

Table 5. Bacterial and viral infections of the mother

Hi-square 5,04202; d.f 2; p 0,0804

Table 6. Taking of medicine during the pregnancy

Legend. Numbers in columns are observed frequencies, percentage for rows, percentage for columns and total percentage.

Hi-square 6,35817; d.f 2; p 0,0416

Legend for tables 7 and 8. Numbers in columns are observed frequency, percentage for rows, percentage for columns, total percentage, frequencies difference, and contribution of the category.

Table 7. Bleeding during the pregnancy

Hi-square 10,54447; d.f 2; p 0,0051

Table 8. Psychic disorders of mother during pregnancy

Hi-square 22,09302; d.f 2; p 0,0000

Perinatal risk factors

Legend for tables 9, 10, 11. Numbers in columns are observed frequency, percentage for rows, percentage for columns, total percentage, frequencies difference, and contribution of the category.

Table 9. Manner of the lead of delivery

Hi-square 3,03333; d.f 4; p 0,5523

Table 10. Presentation of the child

Hi-square 0,11238; d.f 2; p 0,9454

Table 11. Births injuries of the child

Hi-square 0,87300; d.f 2; p 0,6463

Legend for tables 12, 13, 14. Numbers in columns are observed frequency, percentage for rows, percentage for columns, total percentage, frequencies difference, and contribution of the category.

Table 12. Jaundice

Hi-square -1,04895; d.f 2; p 0,5919

Table 13. Hospitalization of the child in the first three years of life

Hi-square 7,12060; d.f 2; p 0,0284

Table 14. Separating mother and child in the first three years of life

Hi-square 11,71403; d.f 2; p 0,0029

DISCUSSION

From the results obtained from our questionnaire, we have found that neuropsychiatric disorders are least found in the group of healthy children, and handicapped groups differ by the type of the disease: members of the family of the autistic children more often have psychoses and neuroses, members of the family of mentally retarded children most often have mental retardation, neuroses and alcoholism. These facts point to possible genetic influence. Among prenatal variables three are singled out: medicine taking during pregnancy (p<0.05), bleeding during the pregnancy (p<0.001) and psychic disturbances of mother during the pregnancy (p<0.001), which are statistically more often in the mothers of autistic children. For the variable of psychic disturbances of the mother during the pregnancy, which is significantly more often in the mothers of autistic children (p<0.001), we have not found the reports in the literature which was at our disposal. The mothers of autistic children in this study were older than the mothers of mentally retarded children (p<0.001). Among risk factors in delivery, three can be singled out: cry at birth, appearance and resuscitation, for which statistical difference could be found among groups (p<0.0l) which were most frequent in mentally retarded children and for the variable abnormal reaction to vaccination which was significant lower (p<0.01) in healthy ones compared to the other two groups. Hospitalization, separation from the mother and the birth of the other child are variables in which risk factor is perhaps psychogenic. Autistic and mentally retarded children were significantly more often hospitalized than the healthy children (p<0.01). In the variable separation from the mother, autistic and mentally retarded children are equal, with slightly greater impact of separation for the autistic children. Both groups differ from the healthy group (p<0.01). Resemblance of autistic and mentally retarded examinees in pre, peri, and postnatal risk factors points to the conclusion that they are important for the handicap, but are not specific for autism. Namely, they are in great number common to autistic and mentally retarded children and both groups significantly more present than in healthy children. Influence of heredity to both groups is great, and the differences between them has already been discussed before.

Risk factors are most prominent in autistic children and has been demonstrated only after summing up all unfavourable conditions in four new variables (heredity, pre-, peri-, and postnatal risk factors).

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