Women may be doing their unborn children a favor as well as themselves by exercising during pregnancy, according to a University of Oklahoma researcher.

Dr. Allison Welder, who has published numerous scientific papers on the development of the fetal heart, is using an in vitro approach to explore the effects of maternal exercise during pregnancy on the development of the fetal heart. She is combining drugs and heart cells from the offspring of both sedentary and exercise-trained pregnant rats in studying this particular process."The preliminary study indicates that exercise during pregnancy is positive for the fetus and development of the fetal heart," she says.

Future research will include looking at the "mechanisms" behind exercise-induced cellular changes to see if effects are lasting in the offspring's heart.

"Women today are exercising regularly during pregnancy, and we don't yet know the impact of that exercise on the fetus," Welder says.

"We do know that exercise affects the heart of the adult human and adult animal in a positive way in that it helps prevent heart disease, or is protective against heart disease.

"Preliminary data indicate that very similar changes occur in the neonatal heart as a result of exercise during pregnancy. If exercise is, indeed, protective against heart disease and it affects the fetus so it's protected into adulthood, then this individual might have an advantage regarding cardiovascular disease later in life."

In essence, Welder says, the baby would be born with a stronger heart that quite probably would remain strong throughout adulthood.

She cautions mothers-to-be to seek their doctors' advice before beginning any form of exercise program.