Waist-to-hip ratio and woman's education level as predictors of breastfeeding duration.

The possible existence of a relationship between breastfeeding duration, educational status and waist-hip ratio (WHR) as a measure of fertility and biological fitness in a sample of the Polish population is examined in this article. Data on age, height, weight, waist and hip circumferences, educational level (as a proxy for socio-economic status), and duration of breast feeding were collected for women using questionnaires in 11 outpatients' surgeries for healthy children, and in 5 general practices in three districts of Wroclaw, Poland. An ordinal multinominal linear model with logit link was used to determine the extent to which duration of lactation was influenced by maternal WHR and level of education. The best single predictor for the duration of lactation was WHR. While WHR decreases according to increasing duration of lactation for mothers with university or high school education, no such differences were observed among women at the lowest level of education. This study confirms the greater biological fitness of women with low WHR in the Polish population, and shows that this is mediated by level of educational attainment of the women.