GESTATIONAL AGE AND NEWBORN SIZE ACCORDING TO PARENTAL SOCIAL MOBILITY: AN INTERGENERATIONAL COHORT STUDY

INTRODUCTION: Girls who were born low birth weight tend to become short women who are more likely to have small children. The objective of this study is to examine the effect of socioeconomic trajectories from birth to adulthood on gestational age and newborn anthropometry in the following generation, using linked data from two population-based birth cohorts carried out  in a Brazilian city. By comparing socioeconomic trajectories of mothers and fathers, we attempted to identify specific effects of early maternal poverty, and compare these to paternal trajectories.

METHODS: In Pelotas, Brazil, two birth cohort studies were carried out.  In 1982 and in 2004, all live births whose mothers lived in the urban area of Pelotas were recruited. Two hundred sixty six children were born in 2004 to mothers (n = 156) and fathers (n = 110) from the 1982 cohort. Gestational age and birth length, weight and head circumference were measured. The effect of social mobility in the first generation on anthropometric variables and gestational age in the second generation was analyzed separately for mothers and fathers.

RESULTS: Among mothers, but not for fathers, childhood poverty was strongly associated with shorter gestations and smaller size in the next generation. For mothers, the associations with gestational age, birth length and weight – but not with head circumference - persisted after adjusting for maternal birth weight and for the height and weight of the grandmother.

CONCLUSIONS: Strong effects of early poverty on gestational age and birth size in the next generation were observed among mothers, but not among fathers. These findings suggest a specific effect of early poverty on the ability of girls to produce well-nourished newborns when they give birth 22 years later.