Insulin titration and blood glucose fluctuations during pregnancy in GCK-MODY: Case Report

Glucokinase-maturity onset diabetes of the young (GCK-MODY) is a form of monogenic diabetes that is caused by heterozygous inactivating mutations in GCK gene. The management of GCK-MODY during pregnancy is challenging, as pharmacological treatment dose could not alter glycaemia in GCK-MODY in longitudinal studies and noninvasive antenatal fetal GCK genotyping is unavailable.

Here, we report a case of GCK-MODY with pregnancy. The patient was 41 years old. She was diagnosed with GCK-MODY at 10 weeks of gestation. At 22 weeks and 6 days of gestation, she underwent amniocentesis due to her advanced age and genetic testing confirmed that the fetus was a heterozygous mutation carrier. We described the characteristics of blood glucose fluctuation, insulin responsiveness, hypoglycemic risk, fetal development, and pregnancy outcome before and after fetus genetic testing during her entire pregnancy. Until now, there were no studies describing insulin titration and blood glucose fluctuations during pregnancy in patients with GCK-MODY.

Our case indicted that insulin therapy during pregnancy is effective in GCK-MODY. Careful dietary modifications, individualized insulin titration and specialized diabetes education can reduce the risk of hypoglycemia and improve gestational outcome in GCK-MODY with pregnancy.