Marked insulin resistance in pregnancy: a case report and literature review.

Pregnancy is usually accompanied by insulin resistance; however, severe insulin resistance in pregnancy requiring massive doses of insulin is rare. We report a case of a 14-year-old with acanthosis nigricans and a strong family history of Type 2 diabetes who exhibited marked insulin resistance during pregnancy. Her treatment included terbutaline for pre-term labor and dexamethasone for fetal lung maturity. Shortly after these interventions, her insulin requirements escalated to 130 units per hour. Multiple insulin regimens were used in her treatment. Investigations were negative for antinuclear antibodies, islet cell IgG auto-antibodies (GAD65 Antibody assay) and insulin antibodies. Her thyroid-stimulating hormone was within normal limits and her C-peptide level elevated at 18 ng/dL [1.1-4.8 ng/L]. A week following cessation of the dexamethasone and terbutaline, her insulin requirements dramatically decreased. We conclude that in pregnant patients with underlying insulin resistance and strong family history of diabetes, the use of agents that antagonize insulin action, such as dexamethasone and terbutaline, can result in massive insulin resistance.