NFBC1966 and NFBC1986
The Northern Finland Birth Cohort Studies is an epidemiological and longitudinal research program which aims to promote health and well-being of the population. The prospective data collected from the Northern Finland forms a unique resource, allowing to study the emergence of diseases which can be based on genetic, biological, social or behavioral risk factors.
The Northern Finland Birth Cohorts (NFBC) were initiated in the 1960s by Professor Paula Rantakallio to examine risk factors involved in pre-term birth and intrauterine growth retardation, and the consequences of these early adverse outcomes on subsequent morbidity. Originally in 1966 when the older cohort (NFBC1966) was started it was named "North Finland premature birth study" or "Development study of children in Northern Finland". The younger cohort (NFBC1986) was begun in 1985 and was originally called as "The mother-child cohort study of morbidity and mortality during childhood with the special purpose of preventing mental and physical handicap". This pioneering prospective data collection now represent a flagship for life-course epidemiology at both national and international level.
NFBC includes two longitudinal and prospective birth cohorts of women and offspring collected at 20-year intervals from the same provinces of Oulu and Lapland: The NFBC1966 was set with an expected date of birth in 1966, comprising of 12,055 mothers and 12,231 children (prospective data collection from maternity cards since 16th gestational week on average), and the NFBC1986 with an expected date of birth between July, 1st 1985 and June, 30th 1986, comprising 9,362 mothers and 9,479 children (prospective data collection from 10th gestational week).
Northern Finland Birth Cohort 1966 Study
The study was started by professor Paula Rantakallio in the two Northernmost provinces in Finland (Oulu and Lapland) already in the year 1965 when the mothers were pregnant. Data on the individuals born into this cohort was collected since the 24th gestational week as well as their mothers and, to a lesser extent, fathers. The cohort included 12055 mothers and they had 12068 deliveries (13 women delivered twice).
Cases belonging to survey were determined by the calculated term. A small percentage of the births occurred towards the end of 1965 and early in 1967. The calculated term, as was customary at that time, was counted from the first day of the last menstrual period. Where this date was unknown the expected term was estimated from the date of commencement of foetal movements and progress of the pregnancy. The study covered all live born and stillborn infants with birth weight of 600 grams or more.
According to the Finland's central Office of Statistics, births in the study area during 1966 totalled 12527, so study population comprised 96.3 per cent of all births during 1966 in that area.
Altogether 12231 children were born into the cohort, 12058 of them live-born. The original data have been supplemented by data collected with postal questionnaires at the ages of 1, 14 and 31 years and various hospital records and national register data.
Northern Finland Birth Cohort 1986 Study
NFBC1986 is a longitudinal one-year birth cohort study from an unselected population. The cohort included all the mothers (N = 9 362) with children whose expected date of birth felt between July 1st 1985 - June 30th 1986 in the two northermost provinces on Finland (Oulu and Lapland). A small percentage of the births occurred towards the end of June 1985 and begin of July 1986.
The number of deliveries in the cohort was 9 362, which was 99% of all the deliveries taking place in the target period of the cohort.
Altogether 9 479 children were born into the cohort, 9 432 of them live-born. The original data have been supplemented by data collected with postal questionnaires at the ages of 7, 8 and 15 / 16 years and various hospital records and statistical register data.