The earliest reference I know of to a recognized causal link between maternal alcohol consumption and fetal developmental issues is 1899, in "A note on the influence of maternal inebriety on the offspring", Journal of Mental Science, 45, 489–503. This is an interesting study because it observed stillbirth rates in female prisoners who consumed alcohol, vs non-incarcerated relatives of the women who did not drink. This was doubly interesting as it showed that developmental issues of the fetus could be caused by something other than genetics - going rather counter to the leading beliefs of the day.

However, Fetal Alcohol Syndrome (and associated spectrum disorder) wasn't formally recognized or named until the 1970s. (Jones, K.L., Smith, D.W, Ulleland, C.N., Streissguth, A.P. (1973). Pattern of malformation in offspring of chronic alcoholic mothers. Lancet, 1, 1267–1271.) This only came after several studies in the 1960s had clearly identified a pattern in maternal alcohol consumption and fetal developmental issues, however.

Sadly, it wasn't until 1978 that this spectrum of disorders was widely recognized in the medical world, and only then did it become "commonly understood". If you want to read more about this, check out Clarren, S.K. (2005). "A thirty year journey from tragedy to hope." Foreword to Buxton, B. (2005). Damaged Angels: An Adoptive Mother Discovers the Tragic Toll of Alcohol in Pregnancy. New York: Carroll & Graf.