Polycystic Ovary Syndrome A previous diagnosis of gestational diabetes or prediabetes, impaired glucose tolerance, or impaired fasting glycaemia A family history revealing a first-degree relative with type 2 diabetes Maternal age – a woman's risk factor increases as she gets older (especially for women over 35 years of age). Ethnicity (those with higher risk factors include African-Americans, Afro-Caribbeans, Native Americans, Hispanics, Pacific Islanders, and people originating from South Asia) Being overweight, obese or severely obese increases the risk by a factor 2.1, 3.6 and 8.6, respectively.[9] A previous pregnancy which resulted in a child with a macrosomia (high birth weight: >90th centile or >4000 g (8 lbs 12.8 oz)) Previous poor obstetric history Other genetic risk factors: There are at least 10 genes where certain polymorphism are associated with an increased risk of gestational diabetes, most notably TCF7L2.[10]