Gestational Diabetes in Primary Care

Paul Hicks, MD

In This Article


Labor is a relatively uncomplicated process, in terms of diabetes care. For the woman whose diabetes is diet controlled, FSBS are done every 2 to 4 hours during labor; for the woman who requires insulin, FSBS are performed every 1 to 2 hours. An intravenous insulin drip is begun if FSBS is > 120 to 140 mg/dL ( Table 5 ).

Maternal complications that may arise intrapartum include PIH and pre-eclampsia, hyperglycemia and hypoglycemia, and arrested labor from shoulder dystocia. PIH and pre-eclampsia are much more common in women with pregestational diabetes, especially those women who have peripheral vascular disease. However, these can also occur in women with GDM, often in association with polyhydramnios. Care of the woman with GDM with pre-eclampsia is no different than care of the nondiabetic patient. Shoulder dystocia occurs in 2% of all pregnancies and in 11% to 14% of pregnancies complicated by GDM.[49,50] There are 2 reasons for this difference in incidence rates: First, the incidence of macrosomia is greater. Second, in GDM there is a significantly increased trunk-to-head ratio compared with nonaffected infants of similar weight.[51] Infants affected by GDM have a predictable appearance of large trunks and shoulders relative to their heads. This effectively impacts them into the pelvis, making passage much more difficult. The risk increases precipitously as fetal weight increases. For infants weighing ≤ 3999 g, the incidence of shoulder dystocia is 9%. For infants weighing 4000 to 4499 g, the risk increases to 14% -- hence, the recommendation for induction at that time. In infants weighing ≥ 4500 g, the incidence of shoulder dystocia for vaginal birth is a startling 38%, making cesarean delivery the preferred route.[49] Of note, however, one third of cases of shoulder dystocia occur in infants weighing < 4000 g.[50] As such, it is important for every provider to be able to manage the delivery of these infants.


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