Hyperemesis gravidarum and cardiometabolic risk factors in adolescents: a follow-up of the Northern Finland Birth Cohort 1986.

OBJECTIVE: To investigate the long-term consequences of prenatal exposure to maternal hyperemesis gravidarum upon offspring cardiometabolic risk factors. DESIGN: This study is part of the prospective follow-up of the Northern Finland Birth Cohort 1986. SETTING: Between 1 July 1985 and 30 June 1986 all pregnant women in two provinces of Finland were recruited at first antenatal visit (99% of eligible participated). POPULATION: A total of 8953 women with liveborn singleton offspring who consented to having their children followed-up were included. METHODS: Hyperemesis gravidarum (HG) was defined as hospitalisation during pregnancy for HG based on the International Classification of Disease (ICD) code. Women who were not hospitalised for HG during pregnancy were used as a reference group. Data on pregnancy and birth outcomes were obtained via medical records and questionnaires; 6462 adolescents, aged 16 years, underwent anthropometric measurements (HG n = 42, reference n = 6420) and 5648 adolescents had a fasting blood sample taken (HG n = 36, reference n = 5612). MAIN OUTCOME MEASURES: Body mass index (BMI), blood pressure, fasting glucose, and lipid levels in offspring. RESULTS: Multivariate regression analyses showed no differences in offspring BMI (kg/m2 ; adjusted percentage difference HG versus reference, 2.2; 95% CI -0.1, 4.6), systolic blood pressure (adjusted difference 2.1 mmHg; 95% CI -1.5, 5.6), and fasting blood glucose (mmol/l; adjusted percentage difference, 2.3; 95% CI -0.6, 5.4), between adolescents born to mothers with and without HG. CONCLUSIONS: We found no evidence that prenatal exposure to HG has negative consequences for cardiometabolic health of offspring at the age of 16 years. TWEETABLE ABSTRACT: Hyperemesis gravidarum does not affect cardiometabolic health in adolescent offspring.

Is geographical distance a barrier in the use of public primary health services among rural and urban young adults? Experience from Northern Finland.

OBJECTIVES: To study the role of distance in public primary health service use in rural and urban local residential areas (1 km² grids) among the young adults of the Northern Finland Birth Cohort 1966 (N = 4503). STUDY DESIGN: Cross-sectional study of a cohort born in Northern Finland in 1966. METHODS: Use of local health centres was surveyed by postal questionnaire in 1997, and distance from study subjects' home to health centre was calculated along road network. The crude and adjusted incidence rate ratios (IRR) and their 95% confidence intervals were calculated for distance, predisposing and illness-level variables. Distance-related health inequity indices were calculated. RESULTS: The IRRs indicated 1.5-fold higher rate of health centre visits among subjects living farther than 10 km compared to subjects living within 2 km from health centre in urban areas. In rural areas, IRRs indicated no significant association with distance and health centre use. No distance-related inequity in the use of health centre services was found. CONCLUSIONS: Distance does not seem to be major barrier in health service use among these 31-year old adults. However, closer study of some groups, such as the rural unemployed, might be valuable.

Body size from birth to adulthood and bone mineral content and density at 31 years of age: results from the northern Finland 1966 birth cohort study.

The purpose of this study was to evaluate the association between body size from birth to adulthood and bone mineral content (BMC) and bone mineral density (BMD) at the age of 31 years in a longitudinal study of the Northern Finland birth cohort for 1966. Data were collected at birth, 1, 14, and 31 years. This analysis was restricted to a subsample of individuals (n =1,099) for whom the BMC (g) and BMD measurements (g/cm(2)) were performed on the distal and ultradistal radius by dual-energy X-ray absorptiometry (DXA) at the age of 31 years. Determinants of low BMC and BMD were analyzed using multivariate logistic regression. Growth retardation at birth, being underweight (BMI < or =20.0 kg/m(2)) at 31 years, and having a low calcium intake at 31 years were associated independently with low BMD at 31 years. Additionally, the proportion of subjects with low BMD was higher among those who had low standardized body weight (< or =1 SD) both at birth and at 14 years, and both at 14 and 31 years. Body weight at 31 years was the strongest associating factor of BCM at 31 years. Growth retardation at birth has long-lasting effects on adult bone mineral content and density of the distal and ultradistal radius independently of later body size, although adult body weight seems to be a most important determinant of BMC at the age of 31 years. Thinness and a low calcium intake are associated with low bone mineral content and density at 31 years of age. Further studies are needed to evaluate if these groups are at increased risk of osteoporosis in old age.

How do persons with intellectual disability manage in the open labour markets? A follow-up of the Northern Finland 1966 Birth Cohort.

BACKGROUND: The aim was to study how many of the individuals with intellectual disability (ID; IQ < or = 70) in an age cohort were not receiving a disability pension by the age of 34 years and what their life situation was like in terms of employment, education and morbidity. In 2000, the Northern Finland 1966 Birth Cohort (n=12,058 live-born) included 129 individuals with ID. METHOD: The outcome data on employment, education, pensions and morbidity were obtained from national registers. RESULTS: A total of 85.3% (n=110) of all the individuals with ID were on pension, and 66 of them had severe ID (IQ <50) and 44 had mild ID (IQ 50-70). Altogether 99 were drawing a pension because of ID, and 11 had a main diagnosis other than ID in the register of Social Insurance Institution. Nineteen individuals with mild ID were not on disability pension. The educational level of those without pension was low, and all whose occupation was known worked in low-level manual trades in the open labour market. During the past 8 years (1993-2000), their employment rate had been lower and unemployment rate correspondingly higher and unemployment periods longer than those of the reference group (IQ >85 or not measured). As to the morbidity, they had been hospitalized twice more often than those in the reference group and the mean of their hospitalization days was over fourfold. CONCLUSION: More attention should be paid to the vocational education and supported employment services of individuals with ID to help them to manage as independently as possible.

Mortality after first hospitalization for chronic obstructive pulmonary disease: changes in 1980-1998.

The prognosis of a hospitalized patient for chronic obstructive pulmonary disease (COPD) is poor. The aim of this study was to determine changes in the prognosis for patients entering hospital for the first time on account of COPD in ten years. Data were gathered from the hospital treatment records maintained by the National Research and Development Centre for Welfare and Health in Finland on periods spent in hospital by persons over 44 years of age with a principal diagnosis of COPD over the interval 1972-1994. Two groups of patients were then distinguished separately those first treated in 1980-1984 and those first treated in 1990-1994, and mortality data sought for these persons in the records of Statistics Finland up to the end of 1998. A total of 11,739 men and 3,048 women were found to have been admitted to hospital with a diagnosis of COPD for the first time in the period 1980-1984. The corresponding figures for the interval 1990-1994 were 8,941 men and 3,628 women. The Cox regression model standardized for age showed mortality to have increased in ten years among both the men [Hazard Ratio 1.093 (95% CI 1.055 - 1.133)] and the women [HR 1.138 (95% CI 1.061 - 1.221)]. This worsening of the prognosis was most pronounced in the age group 45-64 years, where the men had an HR of 1.145 (95% CI 1.060 - 1.236) and the women of 1.412 (95% CI 1.208 - 1.650). The prognosis for men and younger women in particular entering hospital for the first time for COPD deteriorated significantly over a period of ten years. This may partly be attributed to the increased frequency of diagnosis and treatment of COPD in outpatient departments and to the reduction in rehabilitation. The apparent more rapid worsening of the prognosis for women relative to men can largely be attributed to their increased smoking.

Early developmental milestones in adult schizophrenia and other psychoses. A 31-year follow-up of the Northern Finland 1966 Birth Cohort.

Delayed childhood development may precede adult psychoses. We tested this hypothesis in a large, general population birth cohort (n=12058) followed to age 31 years. The ages at which individuals learned to stand, walk, speak, and became potty-trained (bowel control) and dry (bladder control), were recorded at a 1-year examination. Psychiatric outcome was ascertained through linkage to a national hospital discharge register. Cumulative incidence of DSM-III-R schizophrenia, other psychoses and non-psychotic disorders were stratified according to the timing of milestones and compared within the cohort using internal standardization. 100 cases of DSM-III-R schizophrenia, 55 other psychoses, and 315 non-psychotic disorders were identified. The ages at learning to stand, walk and become potty-trained were each related to subsequent incidence of schizophrenia and other psychoses. Compared with the whole cohort, earlier milestones reduced, and later milestones increased, the risk in a linear manner. These developmental effects were not seen for non-psychotic outcomes. The findings support hypotheses regarding psychosis as having a developmental dimension with precursors apparent in early life.

Linguistic and motor abilities of low-birthweight children as assessed by parents and teachers at 8 years of age.

UNLABELLED: Linguistic and motor abilities among low-birthweight 8-y-old children in the northern Finland Birth Cohort for 1985-1986 (n = 9322) were studied using parental and teacher evaluations. The parents of 8370 (90%) and teachers of 8525 (92%) children returned a mailed questionnaire concerning the children's speech, language, learning and motor abilities. Low-birthweight (LBW, < 2500 g) children (n = 279) appeared to have experienced more difficulties than normal-birthweight (NBW, > or = 2500 g) children (n = 8091). The parents evaluated the LBW boys to be the poorest in linguistic and motor skills compared with the other boys or any of the groups of girls. They are therefore presumably at risk of having problems at school, which was confirmed by the teachers' reports. There was also a clear relationship between speech/linguistic and motor disabilities. CONCLUSION: Multivariate logistic regression analyses showed that the lower birthweight and some sociodemographic factors, for example the mother's age being between 20 and 24 y, having more than four children in the family, a reconstructed family, as well as hearing impairment and male gender were the most important determinants of poor speech and language abilities at 8 y of age, with and without adjustment for neonatal risk factors (asphyxia, convulsions, respiratory distress syndrome, bronchopulmonary dysplasia, patent ductus arteriosus). Smallness for gestational age was also a risk factor for poor speech and language skills. Preterm birth was associated with poor skills only after adjustment for the neonatal risk factor. The parental and teacher evaluations were concordant concerning the LBW children's outcome.

Juvenile mortality, mental disturbances and criminality: a prospective study of the Northern Finland 1966 birth cohort.

Mortality, criminality and mental illness among young adults were studied in an unselected birth cohort of 12 058 children born live in Northern Finland during 1966. The cohort members were followed up to the age of 27 years. The total number of all deaths was 117, and 79.5% of these deaths were from unnatural causes. The mortality of males was more than threefold higher than that of females. There was a significantly higher mortality risk in men with schizophrenia (OR, 9.31; 95% CI, 3.14-25.53), other psychoses (OR, 10.28; 95% CI, 2.40-37.02), personality disorders (OR, 4.28; 95% CI, 1.04-14.67) and combined personality disorders and criminality (OR, 3.27, 95% CI, 0.99-9.59). In the group of major mental disorders, 75% of deaths were suicides.

A comparison of clinical and research DSM-III-R diagnoses of schizophrenia in a Finnish national birth cohort. Clinical and research diagnoses of schizophrenia.

As a prerequisite to the use of the Finnish National Hospital Discharge Register in psychiatric epidemiological research, we studied the diagnostic reliability of the register in terms of the psychiatric morbidity experienced by a national birth cohort. We investigated all entries to the register for a sample based upon the Northern Finland 1966 birth cohort at the age of 16 years (n = 11017). Until the end of 1993 (age 27 years), a total of 563 subjects had a register diagnosis indicating a psychiatric illness, 37 of them being schizophrenia. When operational criteria (DSM-III-R) were applied to clinical information in the available original hospital records for cases of psychosis, personality disorder and substance abuse (n = 249), 71 fulfilled criteria for schizophrenia, including all of the 37 cases in the register and an additional 34 (48% false-negatives), most frequently diagnosed in the register as schizophreniform or other psychosis. Despite the official use of DSM-III-R nomenclature, it appears that the clinical concept of schizophrenia in Finland, manifest within the register, remains very restrictive. The application of operational criteria is a necessary prerequisite for scientific research on schizophrenia.

Specific major mental disorders and criminality: a 26-year prospective study of the 1966 northern Finland birth cohort.

OBJECTIVE: The purpose of the study was to examine the quantitative risk of criminal behavior associated with specific mental disorders. METHOD: An unselected 1966 birth cohort (N = 12,058) in Northern Finland was prospectively studied until the end of 1992. The investigation started during the mothers' pregnancy, and the data on the subjects' family characteristics, mental and physical development, living habits, psychiatric morbidity, and criminal records were gathered at various times. RESULTS: The prevalence of offenses was the highest among males with alcohol-induced psychoses and male schizophrenic subjects with coexisting alcohol abuse, and more than half of the schizophrenic offenders also had problems with alcohol. Eleven (7%) of the 165 subjects who committed violent crimes were diagnosed as psychotic. Male schizophrenic subjects had a moderately high risk for violent offenses, but the risk for other types of crimes was not elevated significantly. Odds ratios for criminal behavior were adjusted according to the socioeconomic status of the childhood family and were the same as or slightly lower than the crude odds ratios for all disorders except schizophrenia and mood disorders with psychotic features. CONCLUSIONS: The results indicate that the risk of criminal behavior was significantly higher among subjects with psychotic disorders, even though the socioeconomic status of the childhood family was controlled. The higher risk for violent behavior was associated especially with alcohol-induced psychoses and with schizophrenia with coexisting substances abuse. The results suggest that schizophrenia without substance abuse may also be associated with a higher risk of offenses, but this finding is tentative and requires further investigation.

A 28 year follow up of mortality among women who smoked during pregnancy.

OBJECTIVE: To investigate long term mortality among women who smoked during pregnancy and those who stopped smoking. DESIGN: A follow up of a geographically defined cohort from 1966 through to 1993. SUBJECTS: 11,994 women in northern Finland expected to deliver in 1966, comprising 96% of all women giving birth in the area during that year. Smoking habits were recorded during pregnancy but not later. MAIN OUTCOME MEASURE: Mortality by cause (571 deaths). RESULTS: The mortality ratio adjusted for age, place of residence, years of education and marital status was 2.3 (95% confidence interval 1.8 to 2.8) for the women who smoked during pregnancy and 1.6 (1.1 to 2.2) for those who stopped smoking before the second month of pregnancy, both compared with non-smokers. Among the smokers the relative mortality was higher for typical diseases related to tobacco intake, such as respiratory and oesophageal cancer and diseases of the cardiovascular and digestive organs and also for accidents and suicides. CONCLUSION: The risk of premature death seems to be higher in women who smoke during pregnancy than in other women who smoke. This may be explained either by the low proportion of those who stop later and the high proportion of heavy smokers or by other characteristics of these subjects that increase the risk.

Juvenile offenders, with special reference to sex differences.

Social and demographic background variables relevant to male and female juvenile offenders were studied prospectively in a geographically defined population of 6,007 males and 5,757 females in Northern Finland, together with the distribution of offences by type and number between the sexes. Up to the age of 25 years, 532 males (8.9%) and 60 females (1.0%) had committed at least one crime leading to a criminal record. An intelligence quotient (IQ) of 50-84, but not below 50, was most closely associated with delinquency, as was school performance, in that not only was poor attainment associated with an increased incidence of delinquency, but above-average attainment was also predictive of a lower incidence. This is not interpreted as a causal association but rather an indication of similarity between the demands of the educational system and demands regarding socially desirable behaviour. The demographic, social, educational and health factors predictive of delinquency were very similar for males and females, and the reasons for the difference in the incidence of delinquency between the sexes must be looked for among the general differences in cultural demands and biological factors.

Smoking or quitting during pregnancy: associations with background and future social factors.

Current and future social factors associated with smoking habits during pregnancy were assessed. Data on maternal smoking, social background and the family's development during the 21 years after delivery were gathered for a prospective longitudinal cohort study of 12,068 pregnant women and their children in Northern Finland in 1966 and for a second birth cohort of 9,362 mothers in 1985-86. The prevalence of smoking before pregnancy was 22% in the 1966 cohort (29% in 1985-86). 12% (18%) of the women continued smoking throughout their pregnancy. The following background factors were mainly associated with the mother's smoking and/or continuing during pregnancy in both cohorts when mother's age, parity, place of residence and social class were standardized: mother's age under 23, parity two or more, low social class, urban dwelling, unmarried, gainful employment and heavy smoking. The follow-up responses after 14 and 21 years, respectively, were mostly more favourable among the non-smoking mothers and those who quit smoking during pregnancy-e.g. stable family structure, child's smoking and drinking habits and application for intermediate education. Smoking throughout pregnancy or quitting of smoking late in pregnancy were associated with undesirable future development of the child and family in most of these aspects.

Maternal build and pregnancy outcome.

The effect of maternal build on the outcome of pregnancy was studied in two birth cohorts in Northern Finland, for 1966 and 1985-86. Prospectively collected data were available for 10,969 women in the earlier cohort and 9128 in the later one. The women in the earlier cohort were on average 2.9 cm shorter but 0.2 kg thinner and had 0.7 kg/m2 greater BMI. 13% of the women in the earlier cohort had a BMI below 20, but 24% in the later one, while 96% in both cohorts had BMI below 30. The women with low BMI were on average taller than the others, and at all BMI levels the women of the earlier cohort were shorter and lighter than those of the later one. The outcome of pregnancy was measured by the incidence of pre-term births and perinatal plus childhood deaths up to the age of 4 years, and the association of maternal body measurements with low birth weight (< 2500 g) and small for gestational age (SGA) infants was also studied. An additive logistic regression model was fitted in each analysis, to determine the probability of the outcome separately in terms of BMI, weight and height, adjusting for maternal age, parity, smoking, marital status, father's social class and place of residence. No evidence was found that BMI values 20-25, commonly judged as optimum for the mother's own longevity, predicted a better prognosis for the child than values below 20.(ABSTRACT TRUNCATED AT 250 WORDS)

Teenage alcohol drinking and non-standard family background.

The teenage alcohol drinking in 1980 is described in a cohort of 12,058 subjects born in Northern Finland in 1966, with special reference to non-standard families (with one or both parents absent). The percentage of boys (girls) who had been drinking alcohol at the age of 14 years, was 59.1 (58.3)%, being 57.5 (55.6%) in standard, full families and 66.0 (69.0)% in non-standard families. The percentage of having been drunk was 25.2 (25.1)%, or 22.8 (22.1)% in full families and 36.1 (37.1)% in the non-standard families. When adjusted for the maternal age at birth, place of residence, social class and child's status in the family (firstborn or not, only child or not) by means of regression modelling, the risk of alcohol drinking/having been drunk was still increased in non-standard families, especially in cases of divorce or same-sex parental death, the risk differences as compared to the standard family usually being between 10-20%. The results suggest that a non-standard family structure is associated with early juvenile alcohol drinking. Parental loss or absence may constitute one important factor leading to excessive haste in adopting the adolescent culture, including its potentially destructive habits.

The development of myopia up to the age of twenty and a comparison of refraction in parents and children.

As a part of a longitudinal birth cohort study, refraction was measured at the age of 20 years in 236 persons known to have had myopia at the age of 14 years and 266 controls (2982 refractions). The earlier the myopia had started, the more myopic the eyes were at the age of 20 years. The greatest mean refraction values, -4.94 D for males and -6.62 D for females were found when the change to myopia had started before the age of 10. The mean progression of myopia (the mean progression curves were achieved by calculating the mean refraction values at different ages) seems to continue at least to the age of 20. A female child with a myopic mother is more likely to develop myopia than a female child with a non-myopic mother and the same relation holds good between a male child and his father. The myopic refractive error seems to be greater in the children than in their parents.

The relation between teenage smoking and drinking, with special reference to non-standard family background.

Associations between simultaneous teenage drinking and smoking are considered in a birth cohort born in Northern Finland in 1966 (n = 12,058), especially in non-standard, mainly single parent families. Data were collected from pregnancy until the age of 14. ROC (receiver operating characteristic curve) analysis was used to assess how well smoking predicts use of alcohol. Smoking and drinking were more interconnected in the non-standard families among both boys (p = 0.007) and girls (p = 0.018), but only among boys (p = 0.064) when the data were standardized for social class and place of residence and not among girls (p = 0.191). A similar relation between smoking and having been drunk was found among boys in non-standard families (p = 0.016), even when adjusted as above (p = 0.029), but not among girls (unadjusted p = 0.235, adjusted p = 0.469). The findings suggest that the adolescent boy's self-protective behaviour with respect to the commencement of combined experimentation with smoking and drinking is more restricted in non-standard families than in standard families.

Association of perinatal events, epilepsy, and central nervous system trauma with juvenile delinquency.

The association of perinatal events, childhood epilepsy, and central nervous system trauma with juvenile delinquency was studied prospectively in a geographically defined population of 5966 males in northern Finland. Those who had obtained a criminal record up to the age of 22 years, totalling 355, or 6.0%, were defined as delinquents. The incidence of delinquency was not increased in males with a birth weight less than 2500 g or greater than 4000 g, preterm births < 37 weeks' gestation, or those with perinatal brain damage or having epileptic seizures before 14 years of age. The incidence was increased by 6.8% in the group of males with birth weights less than 3500 g, but not significantly increased after standardisation for a number of social and demographic background variables. The incidence was increased by 10.3% among the males who had had a central nervous system trauma by the age of 14 years, however, and this factor remained significant when social and demographic factors were standardised by regression analysis, with an odds ratio of 1.9 for all males with a criminal record and an odds ratio of 3.15 for those who had committed a violent crime. Previous central nervous system trauma may be a cause of delinquency, or another possibility is that the type of behaviour pursued by males who are likely to commit a violent crime will expose them more often to accidents which can result in central nervous system trauma.

Fitting mixture models to birth weight data: a case study.

Birth weights by gestational age are compared in two birth cohorts from Northern Finland, the first from 1966 and the second from 1985-1986. A curious fact in the data is that mean birth weight before the 39th week was lower in the latter series although the mean birth weight for the total series was higher. Similar findings have been reported in other series. A mixture model with the nonparametric regression function is proposed for studying the hypothesis that the difference was caused by more frequent gross errors in gestational assessment in the earlier cohort. The probability of an error in gestational assessment then greatly depends on the observed gestational age, which makes the mixture model nonstandard. Maximum likelihood solutions to the parameters in the proposed model were computed employing the general expectation-maximization (EM) algorithm. A technique for studying the effect of errors on the intrauterine weight gain curve is proposed and applied to our two birth cohorts. The risk of underestimation of gestational age seems to be larger in the previous series and the differences between the growth curves almost totally vanish when "corrected" by means of the mixture model.