Pregnancy outcome in Finland after the Chernobyl accident

Abstract

The explosion at the Chernobyl nuclear power plant caused radioactive fallout in Finland in April-May 1986. The fallout was unevenly distributed geographically, and, accordingly, the country was divided into 3 fallout zones. Whole-body radioactivity measurements of randomly chosen persons showed that the regional differences prevailed throughout the following 2 years. Data for legal abortions, registered congenital malformations as well as preterm births and stillbirths of malformed children were collected. The corresponding expected figures were obtained from statistics from 1984 and 1985. No differences in the expected/observed rates of the above parameters were detected.

PIP: The effects of the 1986 Chernobyl accident on Finland are reported. Legal abortions, registered congenital malformations, preterm births, and stillbirths showed no differences in observed vs. expected rates after the accident. The limitations are that the population base is small, the detection system is incomplete, no reliable data are available on early abortions, and germinal mutations were not presently analyzed. Measurement of radiocesium (Cs 134 and 137) was accomplished by the Research Institute for Social Security with a stratified random sample of 380 people. 5 fallout zones differentiated groups, which were then collapsed into 3 groups. Regional differences in levels persisted into 1988. The Finnish Register of Congenital Malformations provided the compulsory data on congenital malformations. The 3 groups (children born before the accident in 1984-85, in the latter half of 1986, and in 1987) were analyzed in the 3 zones during 2 study periods (August-December 1986 and January-December 1987). Monthly analysis of induced abortions showed no increase following the accident. There was a slight decrease in births between January and March 1987, which is believed to be related to anxiety reinforced by public advice. There were no differences between expected and observed congenital defects in the 2 study periods. Preterm and stillbirths followed a similar pattern. The analysis showed no association between the temporal and spatial variations in radioactivity and variable incidence of congenital malformations.