Percentile distribution of anthropometric variables in pregnant women

Anthropometric indicators play an important role in the health status assessment of individuals and populations across the different vulnerable groups, due to which it is necessary to ascertain the percentile distribution of the weight, body mass index (BMI), and mid-arm, thigh, and calf circumferences in pregnant women for each week of gestational age. This descriptive and cross-sectional study included 4481 measurements of anthropometric variables obtained from 745 pregnancies out of 719 subjects aged between 19 and 39 years, who were well-nourished, healthy, without clinical edema in the third trimester, with single pregnancy, and validated gestational age. All evaluations were conducted at the Centro de Atencion Nutricional Infantil Antimano, CANIA, from 1998 to 2012. The anthropometric measurements were performed by standardized anthropometrists. Measures of central tendency and dispersion, bivariate correlations, and percentiles 3, 10, 25, 50, 75, 90, and 97 were calculated for each gestational age, between the 8th and 37th weeks of gestation. The number of measurements performed for each studied variable ranged from a minimum of 101 and a maximum of 241 at each gestational week. The BMI and circumference behaviors showed increases as the gestational age advanced. The changes in the variables observed in the 50th percentile between weeks 8 thru 37 were: weight, 10.10 kg; BMI, 4.23 kg/m2; and circumferences (cm): mid-arm, 0.45; calf, 1.60; and thigh, 3.55. The results of this study provide the means to simplify the screening and follow-up of the nutritional status in an accurate manner at any stage of gestation until the 37th week.