A prospective observational study on maternal diet pre- and post-GDM diagnosis and pregnancy outcomes in individuals with/without GDM.

Aims: To investigate (1) the association between maternal dietary choices during the first and second trimesters and the diagnosis of gestational diabetes mellitus (GDM), (2) the association between a GDM diagnosis and dietary choices during pregnancy, and (3) the differences in pregnancy outcomes between individuals with and without GDM.

Methods: A prospective cohort study. Pregnant individuals with singleton pregnancy aged 19 ∼ 44 years, without severe pregnancy complications were enrolled in the study. Dietary data were collected at three time points during routine antenatal appointments: 8 ∼ 12 weeks gestation(n = 993), 20 ∼ 24 weeks gestation(n = 732), and 32 ∼ 36 weeks gestation(n = 536). GDM diagnosis and pregnancy outcomes were collected during follow-up from the electronic medical record (EMR).

Results: A total of 93 participants (12.9%) were diagnosed with GDM. Livestock and poultry meat intake during the second trimester were associated with an increased risk of developing GDM (aOR 1.371, 95%CI 1.070-1.756, P = 0.013), and a GDM diagnosis may lead to decreased intake of cereals and its products (P = 0.001), potatoes and its products (P < 0.001), and fruit (P = 0.002) and increased intake of fish, shrimp and shellfish (P = 0.001), eggs (P = 0.015), and milk and milk products (P = 0.011) in the third trimester. Individuals with GDM related to lower risk of excessive gestational weight gain (aOR 0.384, 95%CI 0.188-0.646, P = 0.001) but may increase the risk of fetal macrosomia (aOR 3.873, 95%CI 1.364-10.996, P = 0.011).

Conclusions: Understanding maternal dietary choices around GDM diagnosis is crucial for accurate nutritional assessment and effective education programs. While our findings suggest dietary changes may occur post-diagnosis, further research is needed to confirm these patterns and the potential benefits of early dietary counseling for individuals with GDM.