Birth Weight and Future Life-span in Finnish Triplets

Aims: Interest in the distribution of birth weight arises because of the association between birth
weight and the future health of the child. A common statistical result is that the birth weight distribution
differs slightly from the Gaussian distribution.
Methods: A standard attempt has been done to split the distribution into two components, a
predominant Gaussian distribution and an unspecified “residual” distribution.
Results: We considered birth weight data among triplets born in Finland in 1905-1959 and compare
the birth weight among stillborn and live-born triplets. The stillbirth rates are 119.1 per 1000 births for
males, 124.6 for females and 121.8 for all. The sex differences are not significant. The still birth rate
for the period 1905-1930 was 119.5 and for the period 1931-1959, 124.2. We identified a strong
association between birth weight of the triplets and their survival. The weight distribution for male
triplets is described well by the Gaussian curve, while for females a slight deviation from the Gaussian
distribution is discernible.