Gestational diabetes mellitus (GDM) can have serious clinical consequences for both the woman and her offspring in the short and long term. Previous research suggests that an interpregnancy weight increase of just 1–2 BMI units is associated with an increased risk of the development of GDM in future pregnancies. 

However, BMI units may not be the most practical approach to addressing weight management (3). In the general population, international guidelines on weight management recommend percentage weight loss for use in clinical practice. 

This study aimed to determine if change in percentage body weight between the start of the first and second pregnancies was associated with the development of GDM in the second pregnancy.