Different subtypes of gestational diabetes mellitus are associated with distinct perinatal outcomes in twin pregnancies

Aims: To determine whether different gestational diabetes mellitus (GDM) subtypes are associated with distinct perinatal outcomes in twin pregnancies. Materials: This retrospective cohort study enrolled women with twin pregnancies who gave birth at a tertiary hospital between January 2017 and December 2022. GDM was diagnosed by the IADPSG diagnostic criteria. Three subtypes of GDM were defined as only abnormal fasting glucose (OAFG) values, only abnormal post-load glucose (OAPG) values and abnormal combined fasting and post-load glucose (ACFPG) values. Logistic regression or generalized estimation equation models were used to test the correlation of subtypes of GDM and perinatal outcomes. Results: GDM with OAPG had a slightly higher risk for preterm delivery (PTD) at <37 gestational weeks (aOR 1.22, 95 %CI 1.01–1.47) and neonatal intensive care unit (NICU) admission (aOR 1.31, 95 %CI 1.09–1.57). GDM with ACFPG were associated with PTD at <37 gestational weeks (aOR 1.42, 95 %CI 1.06–1.89) and PTD at <34 gestational weeks (aOR 1.65, 95 % CI 1.14–2.39). GDM with OAFG had a lower risk of being small-for-gestational age (SGA) (aOR 0.48, 95 % CI 0.26–0.92). Conclusions: Different subtypes of GDM are associated with distinct perinatal outcomes. Only abnormal fasting glucose levels may be responsible for reduced the risk of SGA neonates.