The findings by Jennifer B Kane, assistant professor of sociology at the University of California, Irvine are the first to tie social and biological factors together using population data in determining causes for low birth weight.
"We know that low-birth-weight babies are more susceptible to later physical and cognitive difficulties and that these difficulties can sharpen the social divide in the US.
"But knowing more about what causes low birth weight can help alleviate the intergenerational perpetuation of social inequality through poor infant health," said Kane, formerly a postdoctoral scholar at The University of North Carolina at Chapel Hill, where the research was conducted.
"The odds of having a low-birth-weight baby were one and a half to two times greater for mothers who themselves were born low birth weight compared to mothers who were not born low birth weight," she said.
Also Read
"But also important are social factors, including education and marital status. Putting all of these factors - both intergenerational and intragenerational - together in a single model can tell us even more," said Kane.
For example, education level pre-pregnancy can be transmitted from mothers to daughters across at least three generations, and this intergenerational transmission appears to affect birth weight of future generations, Kane said.
This means that causes of low birth weight extend much further back than the time frame that's typically focused on: pregnancy.
Kane's work shows that key factors can be traced to the mother's own early life experiences, in addition to factors dating back multiple generations.
"This really makes a difference in how we think about planning future population-level policies or programs that intend to reduce social inequalities in birth weight," she added.