What is the best advice for a 20-year married female patient with type 1 diabetes (T1D) for 20 years, hypertension treated with an angiotensin converting enzyme (ACE) inhibitor and a diuretic, and an HbA1c of 8.0%, who is planning to conceive?

Delay Conception Until HbA1c is Optimized

This patient must delay conception until her HbA1c is reduced to <6.5%, ideally as close to normal as possible, to minimize the risk of congenital malformations and other serious pregnancy complications. With her current HbA1c of 8.0%, she faces a significantly elevated risk of diabetic embryopathy, including anencephaly, microcephaly, congenital heart disease, renal anomalies, and caudal regression, as organogenesis occurs primarily at 5-8 weeks of gestation when many women don't yet know they're pregnant 1.

Critical Preconception Priorities

Glycemic Optimization is Paramount

• The American Diabetes Association explicitly recommends effective contraception be prescribed and used until A1C is optimized for pregnancy, with a target A1C <6.5% (48 mmol/mol) 1
• The risk of congenital anomalies is directly proportional to A1C elevations during the first 10 weeks of pregnancy, and her current 8.0% places her at substantially increased risk 1, 2
• Observational data consistently demonstrate that A1C <6.5% is associated with the lowest risk of congenital anomalies, preeclampsia, macrosomia, and preterm birth 1
• While perfect control isn't necessary, good to excellent control can reduce spontaneous abortion risk to rates comparable with non-diabetic women 2

Immediate Medication Review Required

• ACE inhibitors must be discontinued immediately as they are teratogenic and contraindicated in pregnancy 1, 3
• The ACE inhibitor should be replaced with an alternative antihypertensive agent that is safe in pregnancy (such as labetalol, nifedipine, or methyldopa) to maintain her excellent blood pressure control 1
• Statins, if she were taking them, would also need to be discontinued as they are potentially harmful during pregnancy 1, 3
• Her insulin aspart via pump is appropriate and safe for pregnancy and should be continued 4

Address Significant Proteinuria

• Her 24-hour urine protein of 2000 mg/day indicates significant diabetic nephropathy, placing her at substantially increased risk for hypertensive disorders during pregnancy and potential intrauterine growth retardation 1
• This level of proteinuria requires counseling about these specific risks and enhanced monitoring if she does conceive 1
• The nephropathy assessment should be repeated after ACE inhibitor cessation, as these medications can affect protein excretion measurements 1

Why Other Options Are Incorrect

Option A (Eliminate Snacks, Three Heavy Meals)

• This approach is counterproductive and potentially dangerous for a type 1 diabetic on pump therapy 4
• Consistent carbohydrate intake matched to insulin administration is critical, and eliminating snacks could increase hypoglycemia risk 5, 4
• The focus should be on achieving glycemic targets through appropriate insulin adjustment, not meal pattern manipulation 1, 4

Option B (Substitute ARB for ACE Inhibitor)

• Angiotensin receptor blockers (ARBs) are equally contraindicated in pregnancy as ACE inhibitors 1, 3
• Both drug classes are potentially harmful and must be avoided during pregnancy 1
• This substitution would not address the primary issue of suboptimal glycemic control 1

Option C (Begin Statin Therapy)

• Statins are contraindicated in pregnancy and should not be initiated in a woman planning conception 1, 3
• While cardiovascular risk assessment is important in preconception care, starting a teratogenic medication is inappropriate 1
• The priority is glycemic optimization, not lipid management at this juncture 1

Comprehensive Preconception Management Plan

Multidisciplinary Team Approach

• She should ideally be managed by a multidisciplinary team including an endocrinologist, maternal-fetal medicine specialist, registered dietitian nutritionist, and diabetes care and education specialist 1, 3
• This team-based approach has been shown to improve diabetes and pregnancy outcomes when delivered from preconception through pregnancy 1

Additional Preconception Testing and Interventions

• Comprehensive dilated eye examination is essential given her 20-year diabetes duration, as retinopathy may progress during pregnancy 1, 3
• Thyroid function testing (TSH and/or free T4) should be performed given the 5-10% coincidence of thyroid disorders with type 1 diabetes 1
• High-dose folic acid supplementation should be initiated immediately to reduce neural tube defect risk 1, 6
• Cardiovascular assessment may be warranted given her long diabetes duration and nephropathy 1

Intensive Insulin Management

• Frequent self-monitoring of blood glucose (preprandially and postprandially) or continuous glucose monitoring should be implemented to achieve tight glycemic control while avoiding hypoglycemia 5, 4
• Insulin requirements vary across the day, with lower needs at night, a dawn rise, and gradual decrease during the day—her pump settings should be optimized accordingly 4
• The first trimester typically has the most hypoglycemic events, requiring especially close monitoring 4
• Target glucose levels should be fasting 70-95 mg/dL, 1-hour postprandial 110-140 mg/dL, and 2-hour postprandial 100-120 mg/dL 5

Contraception Until Ready

• Effective contraception, with consideration of long-acting reversible contraception (LARC), should be prescribed and used until her A1C is optimized and medications are adjusted 1, 3
• This is a Level A recommendation from the American Diabetes Association 1

Common Pitfalls to Avoid

• Do not allow conception to proceed with HbA1c >6.5%—the risk of major congenital malformations remains elevated even with "good" control, though it can be substantially reduced 2, 7
• Do not substitute an ARB thinking it's safer than an ACE inhibitor—both are contraindicated 1, 3
• Do not focus solely on HbA1c—the daily glucose profile and hypoglycemia frequency are equally important for safe pregnancy outcomes 4
• Do not underestimate the impact of her nephropathy—2000 mg/day proteinuria significantly increases pregnancy risks and requires specialized management 1

Timeline for Conception

• Once HbA1c reaches <6.5% (ideally closer to 6.0% if achievable without significant hypoglycemia), ACE inhibitor is replaced with pregnancy-safe antihypertensive, and other preconception assessments are complete, contraception can be discontinued 1, 7
• If conception doesn't occur within one year of optimized control, fertility assessment should be considered 1
• The patient should understand that achieving optimal control may take several months, but this delay substantially reduces the risk of devastating congenital malformations 2, 7

Answer: D - Delay conception until her HbA1c is as close to normal as possible, if this can be safely achieved