If diabetes in pregnancy can cause so much havoc, can we prevent it?

The answer is yes and the first step is to suspect and diagnose diabetes during pregnancy. Screening for diabetes is a controversial issue. In 1995, Mosses proposed universal screening for gestational diabetes. With universal screening gestational diabetes mellitus was diagnosed in 6.7% of the women overall, in 8.5% of the women aged 30 years or older, in 12.3% of the women with a preconceptionbody mass index of 30 kg/m2 or greater, and in 11.6% of women with a family history of diabetes in a first-degree relative and presence of hypertension before pregnancy or during early pregnancy. Gestational diabetes mellitus was present in 4.8% of the women without risk factors. In races where the risk is the incidence of gestational diabetes is low it may not be cost-effective.

Hence, it may not be practicable in all populations. So a risk stratified approach has been suggested. The diagnostic methods itself was controversial until recently. From the above study, we can deduce that high preconceptional body mass index (>30 kg/m2), older women (>30 years), and family history of diabetes are at risk.

The current recommendations from the American Diabetes Association “Standards of Medical Care in Diabetes—2017”—screen all women for risk factors during first antenatal visit. Very high higher grades of obesity, past history of gestational diabetes mellitus or delivery of an large for gestational age baby, presence of glycosuria and history of polycystic ovarian syndrome and strong family history of type 2 diabetes. For all others screening at 24–28 weeks is recommended and repeat screening for high-risk women whose glucose tolerance was normal in first screening test. It may be avoided in women whose risk of gestational diabetes is very low (aged <25 years, belongs to a race with low risk for diabetes, no family history of diabetes and previous pregnancies were normoglycemia with good obstetric outcome).

The Endocrine Society recommends that all pregnant women at risk but who are not yet diagnosed with diabetes should be screened for the disease with a fasting plasma glucose (FPG), an HbA1c, or a random plasma glucose test at their first prenatal visit. A fasting plasma glucose of 126 mg/dL or higher (≥7.0 mmol/L), a random plasma glucose of 200 mg/dL or higher (≥11.1 mmol/L), or an HbA1c of 6.5% or higher indicates overt diabetes (type 1, type 2, or other), while an FPG of 92–125 mg/dL (5.1–6.9 mmol/L) indicates gestational diabetes.

A diagnosis of overt diabetes must be confirmed with a second test (FPG, untimed random plasma glucose, HbA1c, or oral glucose tolerance test [OGTT]); these must be performed when hyperglycemic symptoms are absent and must be abnormal on another day. At 24–28 weeks’ gestation, a result of 153–199 mg/dL (8.5–11 mmol/L) for a 2-hour, 75-g OGTT indicates gestational diabetes, while a test result of 200 mg/dL or higher (≥11.1 mmol/L) indicates overt diabetes. Whatever is the type of diabetes, the principles of treatment would be the same, but postnatal follow-up and treatment may be modified.