Body composition of pregnant women, during pregnancy and postpartum, and of the baby at the third month of life

Abstract

Objective: To describe the body composition (BC) during the 2nd and 3rd trimester of pregnancy and the mother and child at the third month of life.

Materials and Methods: The study was observational, prospective, and descriptive, and involved convenience sampling. Women were admitted at the beginning of the 2nd trimester of pregnancy, with single gestation, age 20-39 years, and without pathology who required hospitalization. On admission, at the end of the 2nd trimester, in the 3rd trimester, and at the 3rd month postpartum, in addition to weight and height, the (BC) was measured with multifrequency electrical bioimpedance (BIA). In the 3rd trimester and at three months postpartum, (BC) was also evaluated by stable isotopes (0.1g/Kg of D2O) using FTIR (Agilen®) Two saliva samples were taken, at baseline and at 5 hours.

At three months postpartum, the infant's (BC) was also measured using stable isotopes. It's important to note that the study was approved by the INTA Ethics Committee and the participants signed an informed consent form, ensuring the ethical conduct of the research.

Results: Twenty-six women (30±3.4 years) were admitted. The first consultation occurred at 13.7 weeks of pregnancy, with a BMI of 27.5±3.6, 69% with excess malnutrition. The percentage of Fat Mass (%FM) by BIA was 34.3±5.4; (13 to 16 weeks; n=26); 36.6±5.4 (26 to 27 weeks; n=23). In the 3rd trimester (34 to 36 weeks; n=19), the %FM was 37.3±5 (BIA) vs 35.5±5.8 (deuterium). At the 3rd postpartum month (n=11), the %FM in the mother was 36.7±5.6 (BIA) vs 40.4±3.5 (deuterium). At the 3rd month of life, the %FM of the babies was 15.6±1.0.

Conclusion: The study found the %FM increases during pregnancy. Furthermore, the babies in the 3rd month had a %FM according to their age, These findings have important implications for understanding and managing body composition changes during pregnancy and the postpartum period.