Pandanus amaryllifolius and Tectona grandis Extracts Improve Fetal Outcomes in Streptozotocin-Induced Gestational Diabetes in Rats

Gestational diabetes mellitus (GDM) causes adverse effects on both mothers and offspring. This study investigated the effects of a polyherbal formulation combining <i>Pandanus amaryllifolius</i> root and <i>Tectona grandis</i> leaf extracts on maternal and fetal outcomes in streptozotocin (STZ)-induced GDM rats, compared with metformin. Pregnant rats were assigned to a non-diabetic reference group and diabetic groups, including an untreated diabetic group (negative control), a metformin-treated group (positive control), and diabetic groups treated with low, medium, or high doses of the pandan-teak formulation from gestation day 7 to 21. Medium and high doses significantly increased maternal body weight and pancreatic mass index (<i>p</i> < 0.05) without altering maternal glycemia or insulin levels. Fetal weight increased at medium and high doses, whereas crown-rump length increased only at the high dose. Placental index and fetal glucose levels decreased in a dose-dependent manner (<i>p</i> < 0.05), with no significant change in implantation loss. These findings suggest that the pandan-teak formulation may exert complementary actions that support placental-fetal glucose regulation and fetal growth while maintaining maternal glycemic stability, indicating its potential as a plant-based adjunct approach for gestational diabetes focused on fetal protection.