Maternal Galectins and Glucose Regulation in Pregnancy: Chronic vs. Acute Metabolic Adaptations

Background Galectins (gal) are glycan-binding proteins that regulate maternal adaptations during pregnancy, but their role in pregnancy-associated metabolic homeostasis is unclear. This study characterizes the maternal galectin profile in response to an oral glucose tolerance test (OGTT) in pregnant women with varying body weight. Methods In a two-center prospective study, pregnant women were recruited into two cohorts: low-risk (LR) with normal weight and high-risk (HR) with overweight or obesity. Circulating levels of gal-1, -3, -7, and -9 were measured at fasting, 1 hour, and 2 hours during the OGTT between 24 and 28 weeks of gestation. Correlations with clinical and metabolic parameters were assessed (HMO study: ClinicalTrials.gov Identifier NCT05496712; FitFor2 trial: trial registration number NTR1139). Results Fasting gal-3 and gal-9 were elevated in the HR cohort compared to the LR cohort. Body mass index was positively associated with gal-3 and gal-9, while gal-3 was also linked to insulin sensitivity. After glucose challenge, gal-1, -3, -7, and -9 decreased in the LR cohort; in the HR cohort, only gal-1 and gal-7 decreased after 2 hours, while gal-3 and gal-9 remained unchanged. Gal-1 correlated positively with homeostasis model assessment for insulin resistance (HOMA-IR) and inversely with insulin sensitivity across the OGTT in the LR cohort, but some of these correlations were not observed in the HR cohort. Conclusion Galectins exhibited distinct patterns of association with glucose homeostasis during the second trimester of pregnancy. Gal-3 and gal-9 are associated with chronic conditions such as pre-pregnancy obesity and insulin resistance, whereas gal-1 appears to be particularly sensitive to the acute glucose challenge.