Bioelectrical Impedance Vector Analysis (BIVA) for the monitoring of body composition in pregnancy

During pregnancy, body composition alterations can be considered as markers of complications and in this context, a non-invasive and low-cost method such as Bioelectrical Impedance Vector Analysis (BIVA), can be employed to monitor such changes. This study aimed at identifying body compartments trend during physiological pregnancy.

Classic and specific BIVA variables have been measured in a sample of 37 pregnant women approximately every 4 weeks of gestation and once postpartum. Researchers used both longitudinal and cross-sectional approach. The first case included data of women from the 11th to the 15th week along with data from the 28th to the 32nd week of gestation. The cross-sectional approach regarded two more specific moments (11th-12th weeks and 30th-31st weeks) and data within two months postpartum RESULTS: The longitudinal approach showed a significant decrease in classic BIVA variables (R/H, Xc/H, Z/H p < 0.001) and a shortening of the vector, pointing out that TBW and hydration increased significantly. Specific vector length increased significantly, indicating a physiological gain of FM% (p < 0.01). The cross-sectional approach showed lower values of R/H, Xc/H, Z/H between 12th-13th and 30th-31st weeks (p < 0.01), while in the postpartum period values tended to those registered at the beginning of pregnancy. No changes have been found for the phase angle in both approaches, indicating that ECW/ICW ratio remained constant CONCLUSIONS: Among physiological pregnancies, bioelectric values showed a coherent trend and these results represent a first contribution to support routine exams, leading to an early detection of anomalous values potentially correlated to pathologies.