Family and couple properties, and placenta weight in the populations of Białystok and Zambrów, Poland.

The purpose of this study was an analysis of relationships between the traits of families and parents, also recognition of factors determining family properties, including factors responsible for placenta weight. Correlation matrix was used to find relationships among traits, and factor analysis with rotation of the Varimax type was used to identify factors. A total of 795 women were examined, including their placenta and family traits, in the regions of Białystok and Zambrów, in 1977-1978. A correlation matrix of 23 traits of the family and couple, and the weight of placenta during a given pregnancy, was analyzed. A total of 8 factors were discerned, explaining 61.3% of the total variation of the traits. Factor 1 (F1) represented the culture (consciousness) of the family and morbidity of the mother (15.2%), F2-parental age at pregnancy of a given mother (10.4%), F3-living conditions (8.1%), F4-arterial blood pressure of mother (8.1%), F5-body size of the mother (6.5%), F6-traits of the menstrual cycle and morbidity of the mother (5.6%), F7-body size of the father (4.7%), and F8-characterized father's morbidity (4.4%). A relatively low but statistically significant correlation was found between the weight of placenta, on the one hand, and the weight and stature of the mother and number of pregnancies, on the other hand. A little higher correlation was found between the weight of placenta and the morbidity of the mother.