Chinese herbal medicines for treating gestational diabetes mellitus

BACKGROUND Description of the condition Diabetes mellitus (DM) is a complex and chronicmetabolic disorder characterised by hyperglycaemia (high levels of blood glucose) due to beta-cell function or insulin resistance, or both. DMis classified into type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), other specific types of DM, and gestational diabetes mellitus (GDM) on the basis of its aetiology (ADA 2016). T1DM is characterised by absolute insulin deficiency derived from fi -cell dysfunction; while T2DM is characterised by relative insulin deficiency and insulin resistance. GDM is defined as the onset or first recognition of impaired glucose tolerance (IGT) during pregnancy (ADA 2016). GDM is one of the most common complications during pregnancy, and the adverse pregnancy outcomes of GDM have an impact on both mothers and their offspring both during, and after, pregnancy (Robitaille 2008). Pregnant women with GDM tend to have an increased risk of miscarriage, hypertensive disorders, macrosomia (large babies), operative delivery and postpartum haemorrhage, and overt DM after pregnancy (Kim 2002). These women's babies are associated with being large-for-gestational age, premature birth, neonatal respiratory distress syndrome, hypoglycaemia (low levels of blood glucose), and having impaired glucose metabolism at an early age (Kampmann 2015). Dietary control, physical exercises, lifestylemodification, oral anti-hyperglycaemic medications and insulin therapy are the mainstream of current treatment in women with GDM(Martis 2018). Normal blood glucose can be maintained by dietary control and lifestyle modifications (ADA 2001; Harris 2005). Oral hyperglycaemic medications are used when conservative treatment fails to control blood glucose (ACOG 2013; NICE 2015; NZ Ministry of Health 2014), however its long-term effects are still not known. Insulin is used when conservative treatment and oral anti-hyperglycaemicmedications fail to control blood glucose (ACOG2013; NICE 2015; NZ Ministry of Health 2014).