Have there been any studies concerning the effects of aspartame, sweet&low or splenda on fetuses' development?

Has there been any confirmed or disproved findings concerning any possible ill effects on developing fetuses ociated with pregnant mothers consuming any artificial sweeteners? Has there been a study conducted to evaluate whether a link between autism and artificial sweeteners exists? Or are there statistical graphs that chart any potential correlation with the increased overall consumption of artificial sweeteners with the increase of birth defects or abnormalities?