Oral Presentation Society of Obstetric Medicine of Australia and New Zealand ASM 2015

Maternal body composition and energy metabolism in women with an uncomplicated pregnancy at 6 months postpartum, compared to healthy women in their first and third trimesters of pregnancy (#10)

Melissa Ojurovic 1 2 3 , Amanda Henry 1 3 , Minoli Abeysekera 2 3 , Lynne Roberts 1 4 , Jack Morris 2 3 , Greg Davis 1 3 , Anthony J O'Sullivan 2 3
  1. Department of Women and Children’s Health, St George Hospital, Kogarah, NSW, Australia
  2. Department of Endocrinology and Medicine, St George Hospital, Kogarah, NSW, Australia
  3. UNSW Medicine, UNSW , Sydney, NSW, Australia
  4. Faculty of Health, UTS, Sydney, NSW, Australia

Aims: To determine differences in body composition (BC) and energy metabolism between healthy women at 6 months postpartum, and women in their first (T1) and third (T3) trimesters of pregnancy. It is hypothesised that there will be a smaller percent body fat (BF%), altered total energy expenditure (TEE), and energy intake (EI) in women at 6 months postpartum compared to pregnant women.

Methods: Cross-sectional study of healthy women at St George Hospital in T1 and T3 (n=26), recruited in 2012, compared to women with uncomplicated pregnancies 6 months postpartum (n=28), recruited to P4 study (2012-ongoing). BF% and lean body mass (LBM) were measured using multi-frequency bio-impedance analysis. TEE was measured using the SenseWear Armband, worn over 24 hours. This also measures the energy costs of physical activities, the metabolic equivalent (MET). EI was measured using a three-day food recall diary and analysed using Foodworks.

Results: As shown in the Table, there are significant differences in BC and energy balance between women at 6 months postpartum and during pregnancy. BF% was lower in women postpartum than in late pregnancy, but similar to women in early pregnancy. TEE was similar between the three groups, despite postpartum women having a higher average MET compared to T3 women. EI was greater PP than either T1 or T3, while EI/LBM ratio for postpartum women was significantly higher than T3 women.

Conclusions: TEE and MET results suggest energy cost for a physical activity decreases as pregnancy progresses, and increases again postpartum.  Changes in EI and EI/LBM indicate that as pregnancy progresses women have a lower energy-intake while their lean mass is higher. EI/LBM then increases again by 6 months postpartum. We hypothesise that there is a change in metabolic state during pregnancy, requiring less EI per kg LBM, which returns to normal in the 6 months postpartum. These results regarding normal postpartum BC will be used to examine differences in women who had hypertensive pregnancy.