Oral Presentation Society of Obstetric Medicine of Australia and New Zealand and Australasian Diabetes in Pregnancy Society Joint Scientific Meeting 2017

Changes in maternal abdominal subcutaneous fat layers using ultrasound: a longitudinal study (#21)

Narelle Kennedy 1 2 , Ann Quinton 2 3 , Brown Chris 4 , Peek Michael 5 , Ron Benzie 1 , Ralph Nanan 1
  1. Nepean Hospital, Penrith, NSW, Australia
  2. Nepean Medical School, University of Sydney, Penrith, NSW, Australia
  3. Medical Sonography School of Health, Medical and Applied Science, Central Queensland University, Sydney, NSW, Australia
  4. Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
  5. Department of Obstetrics and Gynaecology, College of Medicine, Biology and Environment The Australian National University, Canberra, NSW, Australia

Objectives:Abdominal subcutaneous fat (SF) an important endocrine organ for health outcomes, is divided into two layers, superficial (SSAT) and deep subcutaneous fat (DSAT), each with a different histological and metabolic function (1). Several studies have demonstrated a correlation between DSAT to visceral fat in the role of insulin resistance (2,3). Longitudinal maternal variances of these layers have not previously been examined. The aim, to investigate and describe, using ultrasound, the changes in maternal abdominal SF thickness (adipose tissue distribution), through pregnancy and post-partum within body mass index (BMI) categories. 

Methods: Prospective longitudinal study of 214 women measured abdominal SF using ultrasound at 12-14, 18- 20, 26-29 and 33-36 weeks’ gestation and 6-8 weeks postpartum. SF thickness (SFT) was measured in the midline, SSAT and DSAT were measured, medial to the anterior superior iliac spine using a linear probe. A ratio of DSAT/SSAT(D/S) was calculated.

Results:There were 43.9% (93) normal weight, 25.2% (55) overweight and 30.8% (66) obese recruited. At 12-14 weeks, the mean (SD) SFT measurement was 1.99 (0.91), SSAT 1.11 (0.57), DSAT 0.76 (0.78) centimetres and D/S ratio 0.66 (0.46). The D/S ratio increased with BMI. There were significant interactions of each plot on all abdominal fat compartments confirming a difference in fat mobilization for each BMI category. The obese decreased SFT, SSAT and DSAT during pregnancy. The overweight initially increased DSAT in the second trimester, then decreased SFT and SSAT. In normal weight women, SFT and SSAT remained stable whilst they gained DSAT. The D/S trajectory differed markedly and significantly across BMI categories.

Conclusions: This research has demonstrated a difference in fat mobilisation within the different BMI categories in the SFT, SSAT, and DSAT abdominal subcutaneous compartments in pregnancy.

Clinical significance: Understanding how fat mobilises may be key to understanding obesity related pregnancy complications.

  1. Smith SR, Lovejoy JC, Greenway F, Ryan D, de la Bretonne J, Volafova J, et al. Contributions of total body fat, abdominal subcutaneous adipose tissue compartments, and visceral adipose tissue to the metabolic complications of obesity. Metabolism. 2001;50(4):425-35.
  2. Kelley DE, Thaete FL, Troost F, Huwe T, Goodpaster BH. Subdivisions of subcutaneous abdominal adipose tissue and insulin resistance. American Journal of Physiology-Endocrinology And Metabolism. 2000;278(5):E941-E8.
  3. Gallagher D, Kelley DE, Yim J-E, Spence N, Albu J, Boxt L, et al. Adipose tissue distribution is different in type 2 diabetes. The American journal of clinical nutrition. 2009;89(3):807-14