Weight management during and post-pregnancy in women with and without gestational diabetes mellitus: a mixed methods approach

Abstract

Overweight and obesity prevalence is increasing in women of childbearing age. Pregnancy is an important time physiologically whereby changes in body weight and adiposity naturally occur. Gaining excessive weight during pregnancy has been linked with several serious adverse effects for both mother and offspring. Including increased risk of, caesarean delivery, large for gestational age baby, gestational diabetes mellitus (GDM), and development of obesity in the long-term for both the mother and offspring. Currently within the UK, women are not routinely weighed throughout pregnancy as there are no recommended guidelines specific for use for women within the UK due to a reported lack of evidence as to what the optimal total weight change in pregnancy should be. As a result, conversations around weight management are not happening, resulting in women’s understanding of GWG, and the associated adverse effects remaining poor. Therefore, the overarching aim of this thesis was to evaluate changes in maternal weight during and post-pregnancy and identify factors which contribute to obesity in women with and without gestational diabetes using a mixed-methods approach.

In fulfilment of this aim, a comprehensive literature review assessed the complexities around measuring GWG due to there currently being no gold standard uniform approach to assessing GWG. This outlined the challenges and considerations researchers, and policy makers should consider when initially planning a study or when considering studies to use which will inform guidelines on GWG. In order for successful weight management interventions and public health tools to be developed, the opinions of the target population are invaluable from the early development stage. This thesis used mixed methods to explore the experiences and opinions regarding weight management both during and post-pregnancy through questionnaires (n=108) and follow-on focus group sessions (n=13 participants) of women who had an uncomplicated pregnancy up to 3 years post-pregnancy. Overall, this study identified several barriers to managing weight both during and post-pregnancy, with emphasis placed on the lack of follow-up care post-pregnancy for mothers. Several strategies to help manage weight were also suggested which could help inform future studies including a need for further post-pregnancy follow-ups, support groups which focus on mothers’ needs and signposting relevant information. To provide an insight into weight management within a complicated pregnancy, an evaluation of weight changes throughout pregnancy in women with GDM through weight measurements (n=83) conducted by a health care professional, and an exploration of patient knowledge and attitudes to weight management during pregnancy was explored through a questionnaire (n=123). The majority of women diagnosed with GDM were within the obese BMI category, however excessive GWG above recommended guidelines was found in those within the healthy weight and overweight categories. This data highlighted the importance of all women regardless of pre-pregnancy BMI to be educated on the importance of maintaining healthy adequate GWG during pregnancy. This was further highlighted through the exploration of the Belfast cohort of the Hyperglycaemia and Adverse Pregnancy Outcomes (HAPO) study, which recruited women during pregnancy and followed them up at 2-, 6- and 12-years post-pregnancy. This analysis found that over half of women gained excessive GWG during pregnancy and this trend was observed across all BMI categories, with half or more of participants in each early pregnancy BMI group (healthy weight, overweight, obese) gaining excessively. Those who gained weight excessively during pregnancy maintained the highest BMI across all timepoints post-pregnancy (up to 12 years post-pregnancy), when compared to those who gained inadequately and adequately. This same HAPO data also provided insight into the changes in dietary intake from pregnancy to 12 years post-pregnancy using a Mediterranean Diet score and explored the associations between diet and maternal adiposity and cardiometabolic risk factors. It was identified that the overall Mediterranean diet quality was sub optimal among women during pregnancy and at 12 years post-pregnancy, although scores increased slightly. To our knowledge, this is the first study to apply MEPA longitudinally from pregnancy to midlife in Northern Ireland, providing novel insights into maternal diet and weight trajectories 12 years post-pregnancy. Several chapters within this thesis were used to help inform the initial development of an infographic which aimed to educate on dietary management and weight loss post-GDM in order to reduce women’s risk of developingT2DM. This infographic was then evaluated by (n=21) health care professionals and/or researchers, and was very well received, reporting it addresses a current gap by raising awareness of the importance of weight loss, and a healthy lifestyle behaviours post-pregnancy. Following the evaluation relevant modifications were made and it is planned that this infographic will be disseminated widely via multiple methods across healthcare settings to support women post-GDM. This thesis provided novel findings and contributed to the literature, informing researchers, dietitians, health care professionals and practitioners, and policy makers involved in the promotion of weight management both during and post-pregnancy, in order to reduce the risk/ prevent obesity in the maternal population.

Date of Award	May 2026
Original language	English
Sponsors	Department for the Economy
Supervisor	Alyson Hill (Supervisor) & Alison Gallagher (Supervisor)