Epidemiology of congenital malformations of the central nervous system in (a) Aberdeen and (b) Scotland

Abstract

The incidence of anencephalus and other malformations of the central nervous system (CNS) is much higher in the United Kingdom than in other countries of Western Europe which were not industrialized to the same extent. In the UK the incidence is highest in the unskilled manual occupational group, especially in the large cities of the North of England, Scotland and Northern Ireland. Standards of living have been low in these areas for many years and deteriorated sharply at the time of the worldwide industrial depression from 1928 to 1934. The population tended to be stunted in stature and to show other signs of chronic malnutrition.The cohort of women born in these years had an unusually high stillbirth rate from anencephalus (and from all other CNS malformations) from about 1946 onwards. It was highest in the early 1960s when these women were at the peak of their reproductive activity. This suggests that the severe malnutrition to which they were subjected before and soon after birth resulted in severe damage, which reduced their reproductive efficiency as demonstrated by the unusually high perinatal death rate from all CNS malformations. Not surprisingly the death rate rose sooner, lasted longer and reached a higher level in social classes IV and V than in social classes I and II. Other evidence of damage was an increase in the incidence of low birth weight babies with a corresponding increase in the perinatal death rate from this cause.In Scotland the stillbirth rate from anencephalus was approximately 2-1 per 1000 in 1948^9,3-4 at its highest point between 1961 and 1963and2-l in 1968, by which time the women born in the years of the depression had completed their childbearing. A teratogen acting during a particular period of time could not provide a satisfactory explanation for this sequence of events. 113

The AberdeenChildren of the 1950scohort study: background, methods and follow‐up information on a new resource for the study of life course and intergenerational influences on health

“…The postwar housing stock was also in very poor condition, even compared to cities such as Glasgow, 24 due in part to the difficulty of modernising the granite‐built tenement blocks in which many of the more deprived sections of the Aberdeen population lived. As demonstrated by the classic studies of Baird 25,26 and Illsley, 27 socio‐economic gradients in birth outcome and adult health were clearly evident in this period which represents the formative years of the Aberdeen study members.…”

Beyond Infant Mortality: Gender and Stillbirth in Reproductive Mortality Before the Twentieth Century

“…NICKY HART Another possible explanation of slowing decline in the 1950 is that this was when the birth cohort conceived and born during the Great Depression of the 1930s came of childbearing age. Baird (1974) assembled evidence to demonstrate the existence of an inter-generational lag in birth defects for this birth cohort in Scotland, and it is possible that the slowdown in the risk of stillbirth reflected similar underlying processes. How much faith can we place in this ambitious estimation of the stillbirth trend across the course of the last half millennium?…”

Hemoglobin variations on a small bahamian island

“…The small founding population (less than 40 individuals), the maintenance of low sizes of total population and effective breeding population (1,450 and 383 respectively at present), and the relative reproductive isolation of the community since its formation have all been conducive to the pervasive action of drift. Island populations and others which are inbred to some degree are noted for high incidence of genetic diseases and rare inherited abnormalit-ies (e.g., Baird, 1974;Bonne, 1966;Lewis, 1963;McKusick et al, 1964;Bodmer and Cavalli-Sforza, 1976:372;Lerner and Libby, 1976:342). The elevated frequency of hemoglobin F may itself be the result of the "founder effect" or continuous inbreeding.…”