Aetiological findings and associated factors in children with severe mental retardation.

The purpose of this study, through a retrospective epidemiological survey carried out over three geographical areas in France, was to characterize the aetiological factors involved in severe mental retardation (SMR) within a geographically defined population of children with disabilities aged between 7 and 16 years. The inclusion criteria for SMR (IQ<50) were met by 1150 children born between 1976 and 1985. Of these children, aetiology was known in 25%, suspected (or unclear) in 26%, and unknown in 49%. These rates of known and suspected aetiology varied between the groups of children with CP and those without CP. An analysis of factors associated with SMR was undertaken among the 144 subjects with SMR, of suspected or unknown aetiology, who had been referred to a neonatal care unit with or without intensive care (NCU) during their neonatal period. These subjects with SMR were compared with 864 children without SMR (control children) who were also referred to an NCU during their neonatal period. The main specific associated factors were a prolonged intubation of more than 24 hours, a very low birthweight (<1500 g) for children with an associated clinical feature of CP, and the presence of isolated neonatal fits and a time of transfer to the NCU of more than 4 hours after birth for children without an associated clinical feature of CP. Although common associated factors were encountered in the children with SMR with CP and the children with SMR without CP, the results of this study suggest differences in the underlying pathogenic factors.

[Definition and prevalence of school-age multi-handicaps]. / Définition et prévalence des polyhandicaps à l'âge scolaire.

BACKGROUND: Regulations concerning services for handicapped children in France have defined the notion of multi-handicap. There are, however, divergences in the procedures for applying this definition, and differences in the prevalence in different areas. This study is aimed at clarifying these two points. POPULATION AND METHODS: A survey in three French departments provided data about disabled children born between 1975 and 1985 who received services from the departmental committee for special education or from day hospitals. The data was systematically collected by a physician using medical files. RESULTS: The results showed that the group of multi-handicapped children was heterogeneous. The most restrictive definition (motor disability with profound mental retardation, bed-ridden or restricted to a chair) resulted in a prevalence of 0.73%. A broader definition based on the concept of zero autonomy, but excluding mild or moderate mental retardation, resulted in a prevalence of 1.28%. CONCLUSION: The importance of specifying the objectives of a definition selected for operational reasons is stressed in order to improve the estimation of specific needs.

Visual impairment in children: prevalence, aetiology and care, 1976-85.

Visual impairment (corrected visual acuity in the best eye < 0.3) was evaluated in a retrospective study of 296 children born between 1976 and 1985 and recruited from three French departments. For children younger than 9 years, the overall prevalence was 0.80 per 1000 and that of blindness was 0.28 per 1000. No decrease in prevalence was noted over this decade. The most common aetiologies were antenatal factors (48%), which were observed mainly in the cases of poor vision, and perinatal factors (27%), which were more common in the cases of blindness. Fifty-six per cent of the children had an additional severe handicap. The most common association was with motor impairment and mental retardation. The mean age of first medical care (3.1 years) did not change over the decade: 2.0 years for children with an associated handicap, 2.9 years for cases of isolated blindness and 5.1 years for cases of isolated poor vision. Among children with isolated visual impairment, there was a significantly higher percentage of scholastic underachievers in those presenting after the age of 5 years (39.3% vs. 14.6%).

[Linking of individual data. Methods of linkage]. / Croisement des données individuelles. Méthodes de chaînage.

This paper gives an overview of linking methods of personal data computed in different files as registers and administrative or medical records. Epidemiological and demographic examples are studied, then the successive steps of record linkage are described:definition and choice of identifiants, searching and comparing pairs of records to determine whether they should be linked. A special mention is made to probability matching and methods optimizing the matching procedures. The discussion envisages the advantages of record linkage:better use of health statistics, new types of epidemiologic studies. The ethical problems and the need for evaluation are also discussed.

Prevalence and time trends of disabilities in school-age children.

BACKGROUND: Although the evolution of the prevalence of cerebral palsy is now well documented, much less is known about the evolution of the prevalence of other disabilities such as mental retardation, sensorial defects, autism and psychosis. The aim of this paper is to determine those trends. METHODS: A population-based survey was carried out in 1992-1993 in three French 'départments'. All disabled children born between 1976 and 1985 and receiving a special education and/or financial assistance were systematically registered. RESULTS: The comparison of three cohorts of children born in 1976-1978, 1979-1981 and 1982-1984 using the test for trend in proportion showed a significant decrease (P = 0.03) in the prevalence of severe mental retardation, after exclusion of Down syndrome. This decrease was significant for severe mental retardation associated with psychosis. The time trend prevalence for cerebral palsy increased (P = 0.03) but was irregular. The time trend prevalence of other disabilities (other motor defects, severe sensorial disabilities, autism and psychosis) did not change significantly. A detailed analysis of severe mental retardation and cerebral palsy was performed by geographical area, age at first registration and type of disability. CONCLUSION: The increase in prevalence of cerebral palsy is possibly due to earlier registration of disabled children. The decrease in prevalence of severe mental retardation does not seem to be due to recruitment bias, but there is a possibility of classification bias.

Prevalence, aetiology, and care of severe and profound hearing loss.

Severe and profound hearing loss (> 70 dB) were analysed in a retrospective study of 226 children, born between 1976 and 1985, and recruited from three French administrative departments. The prevalence was 0.54 per 1000 children under 9 years old, with no decrease over the study period. A hereditary origin was identified in 20.8% of cases and an infectious origin in 11.5%. Perinatal risk factors were present in 11.5%, while the aetiology was undetermined in more than half the cases. In 85.8% of the children there was no other severe impairment. Marked learning difficulties were observed: 36% of the children were two years behind their age group and 28% were more than two years behind. The age of initial care decreased over the study period but is still too advanced. Systematic neonatal screening would enable earlier care, which should limit the social and educational impact of hearing loss.

[Cerebral palsy and perinatal asphyxia in full term newborn infants]. / Infirmité motrice cérébrale et asphyxie périnatale chez l'enfant né à terme.

Actual data on the frequency of cerebral palsy (CP) and "infirmité motrice cérébrale" (IMC), and their relationship with perinatal asphyxia and perinatal managements, are presented. In France, the frequency of IMC at 9 years of age, approximates 1 per thousand, for the 1972, 1976, 1981 generations. Three surveys, two English and one Australian, show an association between perinatal asphyxia and CP. However computation of percent attributable risk indicates that asphyxia can explain only one case of CP out of six among term neonates. These surveys show also that 10% of CP only could be prevented by improving perinatal managements. This, in addition to other factors such as the increase in survival of very preterm babies, explains the absence of a significant reduction of CP frequency despite improvements in the perinatal care.

[Motor deficiencies in children: for a nosologic clarification in epidemiological studies]. / Les déficiences motrices de l'enfant: pour une clarification nosologique dans les études épidémiologiques.

In order to clarify the epidemiological research on childhood motor deficiency in France there is a need to better differenciate the two terms used to define this pathology: the French term "infirmité motrice cérébrale" (IMC) and the English term "cerebral palsy" (CP). The distinction between IMC and CP is highlighted on the basis of clinical examples. IMC recovers motor deficiencies which are quite similar, however, it can be very difficult to control the variations in its use. CP has the advantage of a greater exhaustivity as well as a greater reproductibility for epidemiological records. Recently a study was conducted for measuring the prevalence of childhood deficiencies in France, and the results were expressed either as IMC or as CP. When using the CP definition the prevalence rate in France was found to be close to that of foreign studies (1.9 per thousand). In studies with etiological purposes involving several countries, a preliminary agreement on the definition of the clinical groups is absolutely necessary.

[Perinatal risk factors and motor deficiency due to cerebral palsy]. / Facteurs de risque périnatals et déficience motrice d'origine cérébrale.

Despite improvement in perinatal care, the prevalence of cerebral palsy has not decreased in France, Sweden, the United Kingdom or Australia. Based on a review of recent publications, the course of cerebral palsy can be partially explained by the increase in risk among very low birthweight and very pre-term infants whose survival is now better. Until recently, many publications have supported the hypothesis that asphyxia at birth was the major cause of cerebral palsy. However, these results have been widely questioned; the role of asphyxia remained unclear. In 1993 and 1994, several publications showed that there is a significant relationship between asphyxia and cerebral palsy, but that the role of asphyxia was overestimated in the past. The role of maternal and antenatal risk factors must also be taken into account. The prevention of cerebral palsy must be undertaken very early in pregnancy.

[Prevalence of severe mental retardation and trisomy 21 in 3 generations: 1972, 1976, and 1981]. / Prévalence des retards intellectuels sévères et des trisomies 21 dans 3 générations: 1972, 1976 et 1981.

With the aim of studying whether improved prenatal and perinatal care would lead to a decrease in the prevalence of severe mental retardation and/or in Down syndrome, handicapped children born in 1972, 1976 and 1981 and residing in 14 French "departements" were systematically registered in 1985-86 and 1989 in collaboration with the "Commissions Départementales de l'Education Spéciale" (CDES), which centralizes requests for specialty services. The findings showed a stable rates of Down's Syndrome (0.7 p. 1000 in 1972, 0.8 p. 1000 in 1976 and 0.9 p. 1000 in 1981) and of severe mental retardation (1.6 p. 1000 in 1972, 1.5 p. 1000 in 1976 and 1.6 p. 1000 in 1981) in the three generations among children below the age of 9 years. The survey shows that implementation of perinatal health care programs starting in the 1970s, had not been followed by a decrease of severe mental retardation prevalence or Down syndrome prevalence across the three generations 1972, 1976 and 1981.

Motor disability in children in three birth cohorts.

A systematic registration was carried out in 1985-1986 and 1989 in 14 French 'departments' in order to assess whether the prevalence rates of different components of motor disability (MD) in three different birth cohorts (1972, 1976 and 1981) had changed at a time when the preterm birth rate and neonatal mortality were decreasing and there was evidence of changing perinatal practice. A total of 1355 MD were registered amongst resident children born in 1972, 1976 and 1981 with a prevalence of 3.34 per 1000. The prevalence of the MD types due to different causes did not differ significantly amongst the three birth cohorts with the exception of an excess of hereditary and degenerative disease of the central nervous system (CNS) among children born in 1981. The prevalence of cerebral palsy (CP) remained stable in the three birth cohorts: it was 1.30, 1.06 and 1.08 per 1000 respectively, for children born in 1972, 1976 and 1981. The prevalence of pre- or perinatal-origin of other motor disabilities (OMD) and of CNS malformations did not differ amongst the three birth cohorts. The method of registration is discussed and the results are related to those of the French perinatal surveys performed in 1972, 1976 and 1981, which showed a decrease in preterm birthrate, an increase in perinatal care and a decrease in the mortality rate of high-risk infants.

Oral contraceptives and breast cancer: a French case-control study.

The relationship between the risk of breast cancer and oral contraceptive use was investigated in a case-control study conducted in France between 1983 and 1987 in five public hospitals. Some 464 cases aged 25 to 56 years and 542 matched controls were interviewed about their history of the use of oral contraceptives (OC). Results are given for the entire population and for the subgroup of 358 and 379 premenopausal cases and controls. The multivariate relative risk estimate, for ever user, was 1.5 (p less than 0.01) in the whole group as well as in the premenopausal subgroup (p less than 0.02). However, there was no evidence that the effect varied appreciably according to duration of use, age at first use, use before first full-term pregnancy (FFTP) and time since first or last use. The risk was not altered for any particular brand of OC. We conclude that, because of the widespread attention given to the relationship between OC use and breast cancer, information bias might be responsible for part of the excess in risk observed among OC ever users.

PIP: The relationship between the risk of breast cancer and oral contraceptive (OC) use was investigated in a case-control study conducted in France between 1983-87 in 5 public hospitals. Some 464 cases ages 25-56 years and 542 matched controls were interviewed about their history of OC use. Results are provided for the entire population and for the subgroups of 358 and 379 premenopausal cases and controls. The multivariate relative risk estimate, for ever-use, was 1.5 (p0.01) in the entire group as well as in the premenopausal subgroup (p0.02). However, there was no evidence that the effect varied appreciably according to the duration of use, age at 1st use, use prior to 1st fullterm pregnancy, and time since 1st or last use. The risk was not altered for any particular OC brand. The authors conclude that because of the widespread attention given to the relationship between OC use and breast cancer, information bias might be responsible for a part of the excess of risk observed among OC ever-users.

Distribution of ultrasound examination during pregnancy in France between 1976 and 1981.

In France, between 1976 and 1981, the use of ultrasound examination during pregnancy increased from 11.3 to 81.8%. In spite of this dramatic increase, many inequalities observed in 1976 still exist in 1981. Despite a decrease in 1981 of the differences in practice in public maternity units and private care units, large differences remained between general practitioners and specialists. In a logistic regression, the type of practitioner responsible for care appeared to be the most important factor determining access to ultrasound examination. Independent of other inequalities in the type of antenatal care, three groups of women remained disadvantaged in 1981: women under 20 years old, grand multiparas and women of low educational level. The latter group was particularly disadvantaged. Obstetric pathology has little influence on the overall distribution of ultrasound examinations.

Can the number of cesarean sections be reduced without risk? An analysis of rates and indications in a university clinic.

This study concerns women followed from the first trimester of pregnancy, in a university clinic in Paris in 1977, 1979 and 1981. The cesarean section rate was separately analysed for primiparas, and multiparas with and without previous cesarean section. The overall rate of cesarean section was 11.4% in 1977, 17.2% in 1979 and 21.1% in 1981. The 9.6% increase observed between 1977 and 1981 is mainly attributable to an increase in primary cesarean section, particularly among primiparas, between 1977 and 1979. This does not seem to have arisen from sample variations. There is a change in obstetrical attitude and more cesarean sections are performed in cases of hypertension, breech presentation or intrauterine growth retardation. The greater number of previously sectioned women explains the increase in the rate between 1979 and 1981. The main fact among primiparas is the 18.8% increase in diagnosis of dynamic dystocia between 1979 and 1981. Three key areas allow us to envisage a reduction in cesarean section rate: obstetrical attitude towards previous cesarean section, breech presentation, and management of labor, whose perturbations lead to diagnosis of dynamic dystocia.

[Mortality of children aged 1 to 4 years in the countries of the European Community]. / Mortalité des enfants de 1 à 4 ans dans les pays de la Communauté Européenne.

Mortality rates of children aged 1 to 4 years in each country of the European Community were reviewed. Data was drawn from statistics published by the individual countries. Overall, mortality rates were 61 per 100,000 in boys and 51 per 100,000 in girls and are highest in the Republic of Ireland, the FRG and Belgium. Between 1960 and 1980, mortality decreased in all countries and for both sexes; improvement was greatest in the countries where mortality rates were the highest in 1960. Accidents of different types were the main causes of death in each country. Some were related to age group specific behaviour, such as drownings and falls in young children and suffocations in infants. However, most deaths were due to traffic accidents.

[Evolution of the mortality rate of newborn infants transferred to a Parisian intensive care service from 1969 to 1978]. / Evolution du taux de mortalité chez les nouveau-nés transférés dans un service parisien de soins intensifs de 1969 à 1978.

This study reports on the trend in neonatal death rates in a Paris intensive care unit between 1969 and 1978. Three time-periods were compared: 1969-1971, 1972-1974, and 1975-1978. These limits were chosen to take into account the introduction of continuous airway positive pressure in the unit in 1972, and the gradual implementation, from 1972 onwards, of a new perinatal care policy in France. The mortality rate was significantly lower in the second period than in the first, after adjustment on birthweight and type of disease. This trend varied according to type of disease: the death decreased significantly in case of membrane disease or foetal distress, but not in case of admission for amniotic inhalation or congenital anomalies. The gradual improvement in newborn's condition on arrival in the unit played a part in the improvement in survival, as well as the use of the continuous airway positive pressure.

[Fetal hypotrophy. Statistical analysis of placental changes]. / L'hypotrophie foetale. Analyse statistique des modifications placentaires.

The purpose of this research was to study the relationship between placental characteristics and the degree of failure of growth between 37 and 41 weeks of pregnancy. The cases of severe small-for-dates (percentiles of 1 to 5) and moderate small-for-dates (percentiles of 6 to 10) were compared with a control series (percentiles of 11 to 90) with an equivalent gestational age. In both groups of small-for-dates babies one could find that the chorionic arteries and their trunks were of a lower diameter than those of the villi that were small and that there were sub- chorial deposits of fibrin in both groups. The greater number of placental abnormalities were found in those babies who were severely small-for-dates at a gestational age of between 37 and 39 weeks. The relationship between acute fetal distress and small for dates was analysed. There was little difference in the likelihood of fetal distress between the two groups of small-for-dates babies, but there were differences between both groups and the control group.