Final answer:
Approximately 1% of newborns are diagnosed with fetal alcohol syndrome, the most severe form of fetal alcohol spectrum disorders, due to in utero exposure to alcohol with no established safe level of alcohol use during pregnancy.
Step-by-step explanation:
Alcohol exposure during pregnancy can have severe detrimental effects on the developing fetus, leading to a spectrum of conditions known as fetal alcohol spectrum disorders (FASD). From the provided reference materials, we are informed that about 1% of births result in fetal alcohol syndrome (FAS), which is the most severe form of FASD. Newborns with FAS exhibit distinct facial characteristics and may experience developmental delays, cognitive deficits, and behavior problems. Although only a small percentage of newborns are diagnosed with full-blown FAS, the effects of in utero alcohol exposure can vary widely, and there is no established safe level of alcohol consumption during pregnancy.
Considering the global average of live births complicated by malformations due to various factors, it's clear the majority stems from genetics and unknown causes, with environmental factors including maternal alcohol consumption contributing to a smaller fraction of the total. Therefore, when addressing the provided options for the percentage of newborns experiencing adverse effects from in utero alcohol exposure, it seems evident that the correct choice is the minority percentage, reflecting the incidence of FAS as a subset of broader alcohol-related risks.