Chapter 13: Diabetes

PREGESTATIONAL DIABETES

The hallmark of management for women with diabetes mellitus (DM) Type 1 or 2 is pre-pregnancy planning to educate/reinforce the concepts of a proper diet, understand the risks of uncontrolled diabetes before and during pregnancy, and optimize insulin management to achieve proper glycemic control starting as early as possible. The initial study correlating an elevated maternal HbA1c at the time of conception with major congenital fetal malformations found that the risk is approximately doubled when the value is >7% and increased four to five times when the value is ≥8.6%.¹ Subsequent studies have found that the relative risk goes up when the HbA1c is ≥6.6%, and a systematic review noted that pre-pregnancy care can reduce the HbA1c by 1.9%.^2,3 Clinicians should recognize maternal and obstetric issues that identify women at risk of future complications that require immediate forethought and planning on the part of the caregivers, and therefore, “interpregnancy care” begins immediately following delivery.

This proactive planning is intended to engage patients in the risk reduction care plan as early as possible. Because gestational DM (GDM) is a risk factor for Type 2 DM, women with a past history of GDM are the perfect target for this kind of planning as the prevalence of GDM doubled from 2% to 4% in the United States between 1994 and 2002 and tripled in Australia from 2.9% to 8.8% between 1971 and 1994.^4,5,6,7 Identification and treatment of women with persistent postpartum dysglycemia have the potential to decrease hyperglycemia-associated teratogenesis and pregnancy loss in future pregnancies.

PRE-PREGNANCY CARE PLAN

As with any patient, diabetics should have a complete history and physical examination. Usual laboratory evaluation includes a baseline renal function (BUN and creatinine) and a 24-hour urine collection to quantify baseline proteinuria. Normal 24-hour protein excretion is <150 mg/24 hours in nonpregnant women and <300 mg/day during pregnancy. Abnormal excretion of protein is associated with diabetic nephropathy and increases the risk of developing preeclampsia. A spot protein/creatinine ratio may also be used to quantify proteinuria, but it is not as sensitive as a 24-hour collection. The initial clinical exam should include the following elements.

History

• Age of onset and duration of diabetes

• Classification into Type 1 or 2

• History of diabetic ketoacidosis (DKA)

• History of severe hypoglycemia

• Ability to develop symptoms of hypoglycemia

• Retinopathy and/or treatment

• Proteinuria/renal function

• Hypertension

• Neuropathy

• Cardiac disease (obtain electrocardiogram)

• Cerebrovascular disease.

Physical Exam

• Height, weight, BMI calculation, blood pressure

• General exam including assessment of peripheral edema

• Reflexes

• Referral for retinal exam

• Fundoscopic examination.

Labs

• HbA1c

• 24-hour urine collection for proteinuria

• Complete blood count

• Metabolic panel

• Thyroid-stimulating hormone (in Type I DM)

• Echocardiogram not routinely indicated.

When feasible, pregnancy should be ...