ABSTRACT
The objective was to evaluate the prevalence of specific nutritional deficiencies in a group of pregnant adolescents according to the gestational age when they started to receive prenatal care. A group of 163 pregnant adolescents that attended the Instituto Nacional de Perinatología (Mexico City) for the first time to receive prenatal care was evaluated. An anthropometrical evaluation was performed and a blood sample taken to determine hemoglobin, ferritin, erythrocyte folate and plasma zinc to all cases. The mean age was 15 years (11 to 17 years). The mean gestational age when starting prenatal care was 27 +/- 7 gestation weeks and most of them tended to have low weight (97 +/- 12 per cent expected weight for height and gestational age). Eight of every ten adolescents had anemia and iron deficiency. Late prenatal care (> or = 25 weeks) was associated with the risk of presenting anemia OR 5.11 (CI 95 per cent 2.4-10.7) iron deficiency (OR 3.5; CI 95 per cent 1.7 to 7.1) and zinc deficiency (OR 2.9; CI 95 per cent 1.1 a 7.6). In relation to folate deficiency, the opposite effect was observed (OR 0.10; CI 95 per cent 0.02 a 0.48). Lack of opportune prenatal care was associated with the presence of iron and zinc depletion. Probably iron deficiency contributes to an erythrocyte folate accumulation.