The goal of this prospective cohort study is to investigate the contribution of stigma and discrimination due to body size to adverse pregnancy outcomes. We also aim to explore the role of psychological and social factors in this relationship. The specific objectives of this study are:

Objective 1: Explore weight stigma as a mediator of the association between BMI ≥30 kg/m2 and adverse pregnancy outcomes.

Objective 2: Explore confounding factors not previously considered such as weight cycling, trauma, eating disorders, and internalised weight bias as mediators in the relationship between obesity and adverse pregnancy outcomes.

The specific research questions for each objective are:

Objective 1 RQ1.1: Does weight stigma experienced during pregnancy in a healthcare setting reported up to 34 weeks gestation mediate the association between pre-pregnancy obesity (BMI ≥30) and gestational diabetes mellitis (GDM) (primary outcome)?

RQ1.2: Does weight stigma experienced during pregnancy in a healthcare setting reported up to 34 weeks gestation mediate the association between pre-pregnancy obesity (BMI ≥30) and (i) induction of labour; (iv) mode of birth; (ii) gestational hypertension (any); (iii) infant birth weight; and (iv) establishment of breastfeeding by 6 weeks postpartum (secondary outcomes)?

Objective 2:

RQ2.1: Do weight cycling, history of trauma, history of eating disorders, and internalised weight bias explain any of the variance in the mediation relationships described above?

Inclusion Criteria:

• Pregnant between 10-22 weeks' gestation
• Greater or equal than 18 years of age
• Booked to give birth at Adelaide Women's and Children's Hospital or Royal Women's and Children's Brisbane
• Access to the Internet to complete the survey
• Consents to the extraction of hospital electronic medical record data about the woman and relevant to the study.
• Ability to read and understand English

Exclusion Criteria:

• Pregnant with multiple gestation
• Insufficient English language skills to consent and complete the questionnaires.

Women who are pregnant between 10-22 weeks gestation

Participants will be pregnant women who are at least 18 years old with a singleton pregnancy, and who are booked in to give birth at Adelaide Women's and Children's Hospital or Royal Women's and Children's Brisbane. At baseline, women must be between 10 and 22 weeks' gestation.