RESUMO
Pregnancies were compared in 18 Ecuadorian women of low socioeconomic status and 11 of high socioeconomic status. Objective evidence of malnutrition was demonstrable in virtually all of the women from the low socioeconomic group and in none from the high socioeconomic group. Birth weight and placental weight were significantly lower in the malnourished group. Nucleic acid and protein content of placentas were slightly lower and activity of alkaline ribonuclease was markedly elevated. The data reinforce animal studies and demonstrate for the first time in human subjects that alkaline RNase activity is increased in placentas from malnourished women. We suggest that activity of this enzyme in placenta may prove to be a useful marker of maternal and fetal nutritional status.