The widening gap in low birthweight rates between extreme social groups in Poland during 1985-90.

An attempt was made to identify the reasons for the increase in low birthweight (LBW) rates in Poland from 8.1% in 1985 to 8.4% in 1990. It was found that there was a differential increase in the LBW rates among the social groups. The highest increase was observed among the least educated mothers, especially in large cities. The LBW rate among the newborns of mothers who had finished their education at primary school level increased from 10.6% (in large cities from 14.7%) in 1985 to 12.5% (in large cities to 16.2%) in 1990. Controlling for maternal age, parity, education and place of residence did not change the significance of the increase in the LBW rate. The decline in birthweight was probably largely related to negative changes in socially differentiated levels of consumption of basic nutrients in Poland.