Anthropometric Changes During Pregnancy and Their Association with Adequacy of Gestational Weight Gain

Gestational weight gain (GWG) is an expected component of a healthy pregnancy. Gaining weight within the recommended range helps support the mother's health by providing energy reserves and nutrients to meet the increased metabolic demands during pregnancy. Too much or too little GWG has been associated with adverse health outcomes for the mother and child.

The objective of the study was to examine how changes in anthropometric indicators during pregnancy, including fat gain, vary, compare changes among body mass index (BMI) (kg/m²) groups, and examine how the changes were associated with adequacy of GWG defined using the 2009 Institute of Medicine guidelines.

Data came from a cohort of 360 pregnant women with measured anthropometric indicators (weight, midupper arm circumference, and skin folds of the triceps, thigh, and upper iliac) at <12-, 16 to 22-, and 28 to 32-wks of gestation. Fat gain was calculated using a formula. Analysis of variance was used to test for differences in anthropometric changes by BMI and adequacy of GWG in the third trimester. Multiple logistic regression was used to examine associations between changes in anthropometric indicators and GWG recommendations.

Women with normal weight had greater increases in all anthropometric indicators, which differed from women with obesity, who had negative changes and gained less weight. Women who gained inadequately (21%) had negative changes that were all less, compared with women who gained adequately (46%) (except in upper iliac) or excessively (34%). Women with BMI of >25 who gained adequately also had negative changes. Logistic regression results indicated that changes in midupper arm circumference, triceps, and thigh skin folds, and fat gain were all inversely associated with inadequate GWG, whereas all indicators were positively associated with excessive GWG.

Anthropometric changes during pregnancy differ by BMI and are associated with adequacy of GWG. Women who gained adequately had minimal fat gain, lending support for current GWG guidelines.