Interactive diabetes case 11: A 34-year-old pregnant patient with type 2 diabetes – Comment

COMMENT — Diabetes in pregnancy is a common occurrence. The majority of pregnant individuals with diabetes have gestational diabetes, or GDM, which affects 3 to 5 percent of all pregnancies. GDM is defined as the occurrence of diabetes during pregnancy in a woman not known to have diabetes before the pregnancy. Nevertheless, many women who have diabetes during pregnancy have preexistent diabetes, usually type 2 or type 1 diabetes. The incidence of both GDM and pregnancies in women with preexistent type 2 diabetes is likely to increase in the near future because of the epidemic of childhood obesity that is already well established in the United States, especially among certain ethnic groups. The woman with Hispanic ethnicity who is presented in this case is an example of this epidemiologic pattern.

Excellent glycemic management before and during pregnancy is an essential part of the care of women of childbearing age with diabetes (see "Pregestational (preexisting) diabetes mellitus: Antenatal glycemic control"). Pregnancy in diabetes is associated with an increased risk of congenital anomalies and an increased incidence of spontaneous abortions. Meticulous metabolic management before conception reduces these risks appreciably. Nevertheless, only a small fraction of women with type 2 diabetes seeks or obtains prepregnancy counseling and care. While those who do not obtain such care and do not achieve satisfactory glycemia before conception are at increased risk of delivering a child with one or more congenital anomalies or of losing the pregnancy, there are many other reasons to pursue optimal glycemia in those pregnant patients with diabetes who come to attention after conception, including women with GDM and those with type 1 or type 2 diabetes. Such optimized glycemia can reduce or eliminate the complications of pregnancy-associated diabetes that occur during pregnancy and at term, including fetal macrosomia (and its complications, including birth trauma to mother and child), neonatal hypoglycemia, and other neonatal complications (including hypocalcemia, hyperbilirubinemia, polycythemia, and respiratory distress).

The glycated hemoglobin (A1C) is slightly lower in healthy pregnant than nonpregnant women due to increased red blood cell turnover. In the second and third trimesters, an A1C of <6 percent is associated with the lowest risk of large for gestational age infants, preterm delivery, and preeclampsia. Other adverse outcomes increase with A1C values of ≥6.5 percent. Accordingly, a target of 6 to 6.5 percent is recommended, but less than 6 percent may be optimal if these levels can be achieved without hypoglycemia.

The patient developed proliferative diabetic retinopathy during pregnancy despite improved glycemia during pregnancy. She was at risk for this complication because of poor glycemic management for many years. Although she was at increased risk of preeclampsia and was admitted with proteinuria at one point, this diagnosis was not established. The delivery was uneventful, and the child was healthy.

Optimal care of the pregnant patient with diabetes is labor intensive for the patient and her health care providers. The achievement of optimal glycemia requires frequent glucose testing, frequent interactions between the patient and her medical team, close monitoring by a retinal specialist, and frequent obstetrical monitoring. Although these requirements demand time and effort, pregnant patients are often eager to cooperate, motivated by their hopes for a healthy child, their fear of the dreaded complications of pregnancy-associated diabetes, and the knowledge that these demands are for a finite period of time. Too often, women who meet these demands during pregnancy do not maintain their efforts postpartum and their glycemia deteriorates, owing in part to the new demands of caring for an infant.

In one sense, management of a patient with diabetes during pregnancy is comparable with management of any patient with diabetes, with frequent glucose testing, adherence to diet, and appropriate adjustments in insulin doses. However, the demands are greater because of the need for more frequent monitoring and adjustments and challenging because pregnancy-associated diabetes has different requirements for monitoring, different glucose targets, and different algorithms for insulin use. In addition, the patient needs monitoring by a retinal specialist and an obstetrician. For these reasons, it is usually appropriate to refer a patient with diabetes who wishes to become pregnant or a pregnant patient with diabetes to a center with a multidisciplinary team including an endocrinologist, a certified diabetes educator, a registered dietitian, a retinal specialist, an obstetrician, and supporting staff. When this cannot be done, the clinician should attempt to assemble such a team to the extent possible.

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