Document Type

Theses, Ph.D


Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence

Publication Details

Thesis for the Degree of Doctor of Philosophy (PhD) Technological University Dublin, March 2016.


Maternal obesity increases the risk of metabolic complications in pregnancy such as gestational diabetes mellitus (GDM). Effective weight management following childbirth may reduce long-term metabolic risks among women of child bearing age. The aim of this study was to investigate the diet and health behaviours of pregnant and postpartum women in Ireland. Accurate dietary assessment in pregnancy is often difficult to achieve. We have shown that dietary under-reporting is more likely among pregnant women who are younger, materially deprived, obese and who have increased adiposity. These findings suggest that dietary underreporting represents a source of potential bias in obstetric obesity research. Obese pregnant women of low socioeconomic status may require more specialised dietary assessment methods. Technology increasingly dictates the way in which we collect and communicate information, highlighting the potential utility of innovative web-based dietary assessment and intervention tools. We compared dietary quality scores from a newly developed online Dietary Assessment Tool against nutrient intakes derived using the recently validated Willett Food Frequency Questionnaire. The relatively good agreement between these two dietary assessment methods suggests that our food-based dietary quality scores are reflective of important nutrient intakes in pregnancy.

Nutritional manipulation based on dietary intervention does not appear to prevent GDM. Neither food group nor macronutrient intakes in the periconceptional period were associated with fasting plasma glucose (FPG) levels in our cohort of pregnant women. Obesity in early pregnancy was the main predictor of elevated FPG levels, highlighting the potential value of preconceptional weight management interventions in preventing GDM. There is a paucity of data describing maternal weight changes in the postpartum period. We found that maternal weight and body composition trajectories after pregnancy were not linear, and that they differed between women who were obese and those who were not obese in the first trimester. The role of breastfeeding in postpartum weight change is not clear. We found that postpartum changes in maternal weight and percentage body fat were not associated with infant feeding method after adjusting for important confounders such as diet and exercise. Overall, my findings commend the pre-conceptional period as an important window of opportunity in the prevention of GDM and postpartum obesity.