Postpartum Body Composition: A Case Study Of Two Pregnancies

Abstract

Numerous changes to body composition occur during and post-pregnancy in apparently healthy women. Significant changes, specifically to fat mass and bone mineral density, have acute and chronic impacts on overall wellness. PURPOSE: The purpose of this case study is to examine the body composition changes of a woman in her 30s over two pregnancies. METHODS: Dual-energy x-ray absorptiometry (DEXA) scans were performed before each pregnancy and two weeks, five months, and twelve months after delivery. At each scan the participant was asked about physical activity, lactation status, and supplementation. RESULTS: DEXA scan results prior to pregnancy 1 (P1) and pregnancy 2 (P2) were similar for all variables, except total bone mineral density. However, the individual gained considerably more fat during P2 (P1: 15.7 lbs; P2: 28.7 lbs fat gained). Five months post-pregnancy, fat mass was still elevated (P1: 3.8 lbs; P2: 12.7 lbs over baseline) and continued to decrease until 12 months after delivery. Lean mass was increased from baseline at two weeks post-pregnancy (P1: 96.52 lbs.; P2: 97.1 lbs). However, gained lean mass was lost by five months postpartum (P1: 89.89 lbs.; P2: 91.2 lbs). During P1, lean mass remained about the same from five to 12 months but increased at 12 months after P2 (96.2 lbs). After P1, the individual had a substantial decrease in bone mineral density, losing 0.49% at two weeks postpartum, 4.68% at five months, and 9.20% twelve months. Bone mineral density remained below baseline prior to P2, but did not decrease as dramatically following P2. Using the initial baseline, bone mineral density was 3.53% lower at two weeks, 6.57% at five months, and 7.64% at 12 months. During both postpartums, the trunk (P1: 12.1%; P2: 11.54%), spine (P1: 13.5%; P2: 11.36%), and pelvis (P1: 12.4%; P2: 14.34%) decreased more than total bone mineral density. At each appointment, the participant reported breastfeeding, being physically active, but did not exercise consistently CONCLUSIONS: Exclusive breastfeeding combined with an active lifestyle but no formal exercise was adequate to restore fat mass and lean mass by 12 months post-partum. Total bone mineral density decreased following both pregnancies. The baseline bone mineral density for the second pregnancy was lower than the initial baseline, but less decline post-partum.