Just how early do these fatty streaks start to appear? Atherosclerosis may start even before birth. Italian researchers looked inside arteries taken from miscarriages and premature newborns who died shortly after birth. It turns out that the arteries of fetuses whose mothers had high LDL cholesterol levels were more likely to contain arterial lesions.23 This finding suggests that atherosclerosis may not just start as a nutritional disease of childhood but one during pregnancy.