Part of the Fat Component in the Structure of Gestational Weight Gain

Gestational weight gain (GWG), which is more or less of the recommended guidelines, has serious short- and long-term negative consequences for the health of the mother and children. Determining the dynamics of body composition during pregnancy is important for full antenatal care in order to prevent pathological weight gain and prevention of gestational complications.Objective: Our goal was to determine the proportion of fat component in the structure of GWG in women with normal body weight before pregnancy. Design: 153 pregnant women aged 18-43 years with normal pre-pregnancy body mass index (pBMI) were examined. BMI was calculated by using the standard formula of person’s weight in kilograms divided by the square of his height in meters (kg/m2). Total weight gain was calculated by subtracting the pre-pregnancy weight from the last measured weight before delivery. The body composition (fat mass (FM), fat-free mass (FFM), and the percentage of fat mass (%FM)) was calculated on the basis of bioelectrical impedance analysis (BIA) using the ‘DIAMANT-AIST’ analyzer (St. Petersburg). Statistical analyses were carried out using Statistical program "Statistica 5.5".Results: It has been established that in women of normal weight before pregnancy, GWG was directly proportional to an increase in the fraction of FM (r=0.87; p 0.05), however, it was accompanied by low growth of the FFM, especially in the third trimester (p<0.05). Pregnant women with excessive GWG were more likely to gain weight in the first trimester mainly due to the accumulation of FM (p<0.05), and this tendency remained until delivery r=0.99 (p<0.01).Conclusion: In women with normal GWG there is a monotonous increase in fat component in the first and second trimesters, and subsequently stabilized, which promotes adequate weight reduction after childbirth. In patients with high GWG, the excessive increase in the proportion of FM and, consequently, a rapid increase in weight in the first trimester of pregnancy, initiates further accumulation of adipose tissue and slows down its reduction in the postpartum period. In pregnant women with low weight gain there is adequate increase of FM but an insufficient increase of FFM, especially in the third trimester, which leads to the development of placental hypoplasia and small-for-gestational age.