Concept: Diabetes in Pregnancy - Differentiating Between Maternal Pre-Gestational Diabetes and Gestational Diabetes
Last Updated: 2015-11-26
Reliance on the use of ICD 9-CM and ICD-10-CA codes for discrimination between pre-gestational and gestational diabetes is problematic in administrative data as not all diabetes diagnosed in pregnancy is gestational diabetes. Diagnosis of diabetes in pregnancy prior to 21 weeks’ gestation most likely represents undiagnosed pre-gestational diabetes, not gestational diabetes itself. This is important as the timing of hyperglycemia influences the fetal and maternal outcomes expected. This definition relies on the timing of diagnosis rather than the ICD-9-CM and ICD-10-CA code itself as diabetes first diagnosed in pregnancy is often termed and coded as gestational diabetes when it may not strictly be so. Gestational diabetes is a risk factor for subsequent type 2 diabetes and probably exists on a continuum in at risk individuals. Additionally the diagnosis of gestational diabetes is hampered in ICD-9-CM as the 4th digit is required to discriminate from other complications of pregnancy. Standards exist for administrative data diagnosis of types 1 and 2 diabetes but not for gestational diabetes.
Determining if the maternal pre-gestational diabetes is Type 1 or Type 2
For those women identified as having pre-gestational diabetes, determine the pre-gestational diabetes type (Type 1 or Type 2), using the following process:
- As reported in the Diabetes Education Resource for Children and Adolescents (DERCA) data .
- Based on the woman’s first diabetes hospital code reported in the 2 year diabetes evaluation period.
Type 1: if ICD-9-CM codes 250.x1, 250.x3; ICD-10-CA codes E10, O24.5, O24.0.
Type 2: if ICD-9-CM codes 250.x0, 250.x2; ICD-10-CA codes E11, O24.6, O24.1.
- Type 2: if the woman did not receive any diabetes drugs during her gestation period (using the Drug Program Information Network (DPIN) data).
- Type 2: if the woman only received a non-insulin diabetes drug (i.e.: ATC = A10B) during her gestation period.