MKSAP quiz: Preconception testing
This month's quiz asks readers to provide preconception counseling to a patient with type 1 diabetes with no known microvascular or macrovascular complications.
A 28-year-old woman is evaluated for preconception counseling. She desires to achieve pregnancy in the next 6 months. Medical history is significant for type 1 diabetes mellitus diagnosed at 12 years of age. She has no known microvascular or macrovascular complications of diabetes. She is up to date on screening for microvascular complications with her last eye examination performed 11 months prior and a normal creatinine level, urine albumin-creatinine ratio, lipid panel, and foot examination 9 months prior. Thyroid-stimulating hormone level was 0.5 µU/mL (0.5 mU/L) 3 months ago. She is currently using a condom for contraception. Medical history also includes autoimmune thyroid disease. Medications are insulin lispro delivered through continuous subcutaneous insulin infusion and levothyroxine.
On physical examination, vital signs are normal. Nondilated retinal examination, thyroid examination, and monofilament testing are all normal.
Laboratory studies reveal that hemoglobin A1c level is currently 6.7%, improved from 9% 3 months ago.
Which of the following is the most appropriate preconception management to perform next?
A. Dilated eye examination
B. Fasting lipid profile
C. Nephrology referral
D. Thyroid-stimulating hormone measurement
E. Urine albumin-creatinine ratio
MKSAP Answer and Critique
The correct answer is A. Dilated eye examination. This item is available to MKSAP 18 subscribers as item 32 in the Endocrinology and Metabolism section. More information about MKSAP 18 is available online.
The most appropriate preconception management for this patient is a dilated eye examination. Women with type 1 or type 2 diabetes mellitus who are planning pregnancy should be counseled on the risk of development or progression of diabetic retinopathy. Additionally, rapid improvement in glycemic control in the setting of retinopathy is associated with temporary worsening of retinopathy. Given tight glycemic targets in pregnancy, this is often a time of intensified glycemic control for women placing them at greater risk for this complication. Dilated eye examinations should occur before pregnancy or in first trimester if not done prior to pregnancy. Patients should be monitored every trimester and then closely for 1 year postpartum as indicated by the degree of retinopathy.
This patient is up to date on lipid screening and additional screening as part of preconception management is not necessary.
Thyroid-stimulating hormone (TSH) levels should be monitored closely in pregnancy due to increased level of thyroid-binding globulin in pregnancy resulting in increased levothyroxine needs. This patient has had a TSH measurement with normal results 3 months ago. The dose of levothyroxine may need to be increased on average by 30% to 50% during pregnancy, and patients should have their TSH level checked as soon as a pregnancy test is positive.
A referral to a physician experienced in the care of kidney disease should be undertaken in patients with advanced kidney disease, which is not present in this patient as her most recent serum creatinine and urine albumin-creatinine ratio were normal.
Key Point
- Women with type 1 or type 2 diabetes mellitus who are planning pregnancy should be counseled on the risk of development or progression of diabetic retinopathy; rapid improvements in glycemic levels during pregnancy can temporarily worsen preexisting retinopathy.