Women with pre-existing type 1 and type 2 diabetes (including those in whom the diabetes was not recognised before pregnancy) have an increased risk of adverse pregnancy outcomes, including miscarriage, foetal congenital anomaly and perinatal death (National Collaborating Centre for Women’s and Children’s Health 2008). To minimise risks associated with pregnancy and established type 1 or 2 diabetes, pre-conception planning and care is critical. Evidence suggests pre-conception care with tight glycaemic control (HbA1c levels should be as close to normal as possible) improves outcomes including decreased perinatal mortality and decreased congenital malformations (Chiang et al 2014). The prevalence of type 2 diabetes is increasing in women of reproductive age and outcomes may be equivalent or worse than in those with type 1 diabetes (Scottish Intercollegiate Guidelines Network [SIGN] 2010). Medications used by such women should be evaluated prior to conception, since some drugs commonly used to treat diabetes and its complications may be contraindicated or not recommended in pregnancy, including statins, ACE inhibitors, angiotensin receptor blockers (ARBs), and some noninsulin therapies.
Pregnancy can affect glycaemic control in women with pre-existing diabetes, increasing frequency of hypoglycaemia and hypoglycaemia awareness, and the risk of ketoacidosis. General anaesthesia in women with diabetes can also increase the risk of hypoglycaemia. The progression of certain complications of diabetes, specifically diabetic retinopathy and diabetic nephropathy, can be accelerated by pregnancy (National Institute for Health and Care Excellence [NICE] 2008). Infants whose mothers with diabetes received dedicated multidisciplinary pre-pregnancy care showed significantly fewer major congenital malformations (approximating to the rate in non-diabetic women) compared to infants whose mothers did not receive such care (SIGN 2010).
Contraception should be discussed on an individual basis with all women of childbearing age with diabetes. There is little evidence of choice of contraceptive method specifically in these women. In general, the contraceptive advice for a woman with diabetes should follow that in the general population (SIGN 2010).