Smedby B, Ericson A
Acta Paediatr Scand Suppl. 1979;275:41-6. doi: 10.1111/j.1651-2227.1979.tb06159.x.
The perinatal mortality among the infants of foreign and Swedish mothers was studied with the help of the data submitted to the medical birth register in 1973--1976. Unexpectedly, the perinatal mortality was slightly lower among the infants of the immigrant mothers. This difference could not be explained by differences in the distribution by age or parity of the mothers or by the length of gestation of the infants. A conceivable explanation is that the foreign mothers constituted a favorably selected group.
