London, Aug 19 (IANS): British researchers have found that smoking during pregnancy has discernible effects on the growth of a woman's future grandchildren.

With non-smoking mothers, if a paternal grandmother smoked during pregnancy, her granddaughters tended to be taller and both her granddaughters and grandsons tended to have greater bone mass and lean (muscle) mass, researchers noted.

If a maternal grandmother smoked during pregnancy, her grandsons became heavier than expected during adolescence, with increased lean mass, grip strength and cardiovascular fitness.

When both the maternal grandmother and the mother had smoked, girls had reduced height and weight compared with girls whose mothers, but not grandmothers, smoked.

“These likely transgenerational effects from the grandmothers' smoking in pregnancy need to be taken into account in future studies of the effects of maternal smoking on child growth and development,” said senior study author professor Marcus Pembrey, a clinical geneticist who previously worked in the Institute of Child Health at University College London.

If replicated, such studies could be a useful model for the molecular analysis of human transgenerational responses, he added.

The study appeared in the American Journal of Human Biology.