Objectives: The aim of this study is to examine alanine aminotransferase (ALT) levels in a cohort of women diagnosed with gestational diabetes mellitus (GDM) and to investigate the association between elevated ALT and pregnancy outcomes. Design: A retrospective cross-sectional study. Setting: Cork University Maternity Hospital Population: Women attending the gestational diabetes outpatients’ department in CUMH. Methods: This is a retrospective cross-sectional study. The participants were divided into 2 groups: those with ALTs within the ALT N range and those with elevated but with no other documented diagnosis of liver disease that may be a cause for their elevated ALT level. Primary and secondary measure outcomes: a) To quantify the number of participants with an elevated ALT and to compare them to a group of participants with normal ALT, b) To investigate if there is an association between elevated ALT and BMI and c) To compare the two groups in terms premature birth, macrosomia, induction of labour, operative delivery and neonatal ICU admission. Results: 24.7% of women with GDM had elevated ALT. 23.9% of the entire group had elevated ALT and no diagnosis of liver disease. When this group was compared to the group with ALT N, there was a statistically significant association between elevated ALT and both elevated BMI and premature delivery. Conclusions: In this cohort there is an association between GDM and increased ALT. There is also an association between elevated ALT and increased BMI and premature. These groups should be treated as high risk pregnancies.