Class C Diabetes: Understanding Pregestational Diabetes and Its Impacts on Pregnancy

Navigate the complexities of Class C pregestational diabetes to ensure safer, healthier pregnancies through informed care and management.

By Medha deb

Created on Sep 26, 2025

Navigate the complexities of Class C pregestational diabetes to ensure safer, healthier pregnancies through informed care and management.

Class C diabetes, a specific classification within pregestational diabetes, presents unique challenges for women planning or experiencing pregnancy. Understanding its causes, symptoms, diagnosis, and potential complications is essential for optimizing both maternal and fetal health throughout pregnancy. This comprehensive guide explores all key aspects of Class C diabetes, along with practical advice for mothers-to-be.

What Is Pregestational Diabetes?

Pregestational diabetes refers to type 1 or type 2 diabetes that is diagnosed before a person becomes pregnant. This is distinct from gestational diabetes, which develops for the first time during pregnancy. The presence of diabetes prior to conception adds risks that require careful management for a healthy pregnancy outcome.

Pregestational diabetes can be either type 1 (autoimmune, insulin-dependent) or type 2 (insulin resistance).
Unlike gestational diabetes, pregestational diabetes is a condition existing before pregnancy.
It is divided into several classes based on age at onset, disease duration, and complications.

Understanding Class C Diabetes

Class C diabetes is one of the classifications used by medical professionals to describe the severity and duration of diabetes in pregnant individuals.

Class C diabetes is diagnosed if you developed diabetes between ages 10 and 19 or if you have had the disease for 10 to 19 years without vascular complications.
This classification helps healthcare providers tailor pregnancy care plans.
Women with Class C diabetes require extra monitoring and support during pregnancy.

Symptoms of Diabetes

The symptoms of diabetes arise from high blood glucose levels and can overlap with normal pregnancy symptoms, making diagnosis and management more complex.

Excessive thirst and hunger
Frequent urination
Unexplained weight changes (loss or gain)
Extreme fatigue or tiredness

Prenatal symptoms such as increased urination and fatigue may be caused by both pregnancy and uncontrolled blood glucose, so it’s essential to monitor glucose levels to distinguish the source.^,

Causes and Risk Factors of Pregestational Diabetes

There are several well-recognized contributors to the development and progression of pregestational diabetes:

Type 1 diabetes is primarily autoimmune, often presenting at a young age (including in adolescence).
Type 2 diabetes is associated with genetic predisposition, obesity, lifestyle factors, and insulin resistance.
Family history of diabetes increases the risk.
Previous history of gestational diabetes, polycystic ovary syndrome, or metabolic syndrome may also increase risk.

Diabetes diagnosed in adolescence or early adulthood is more likely to be classified as Class C in pregnant individuals.

Diagnosing Pregestational Diabetes

Prenatal diagnosis of pregestational diabetes — including the identification of Class C — is based on blood glucose testing and medical history.

Test	Normal Range	Prediabetes	Diabetes
Fasting plasma glucose	< 100 mg/dL	100–125 mg/dL	≥ 126 mg/dL
Random plasma glucose	N/A	N/A	≥ 200 mg/dL + symptoms
Hemoglobin A1c	< 5.7%	5.7–6.4%	≥ 6.5%

Diagnosis relies on comprehensive medical and family history, duration of diabetes, and exclusion of vascular complications. Women are also regularly screened for complications such as nephropathy and retinopathy during prenatal visits.^,

Classes of Pregestational and Gestational Diabetes

Classes of Pregestational Diabetes (White’s Classification)

White’s classification is used to assess the severity of pregestational diabetes. Understanding these classes is crucial for risk assessment and treatment planning:

Class A: Diet-controlled, any age at onset, minimal to no complications.
Class B: Diabetes onset after age 20, disease duration less than 10 years, no vascular complications.
Class C: Onset between ages 10–19 or duration 10–19 years, no vascular complications.
Class D: Onset before age 10, duration over 20 years, or presence of certain vascular complications.
Class F: Diabetes with nephropathy (kidney involvement).
Class R: Diabetes with retinopathy (eye involvement).
Class RF: Both nephropathy and retinopathy complications present.
Class T: History of kidney transplant due to diabetes.
Class H: Diabetes with established coronary artery disease.

Classes of Gestational Diabetes

Class A1: Diet-controlled gestational diabetes.
Class A2: Gestational diabetes managed with medication (oral agents or insulin).

Gestational diabetes is generally temporary but increases risk for future type 2 diabetes.

Treatment and Management of Class C Diabetes in Pregnancy

Women with Class C diabetes require individualized management protocols to reduce risks to both mother and baby.

Key Components of Treatment

Blood glucose monitoring: Frequent (often daily) checks of blood sugar using home meters or continuous glucose monitors.
Insulin therapy: Adjusted as needed because pregnancy changes insulin requirements; most women with Class C require insulin.
Diet and nutrition: Meal planning focused on balanced carbohydrates, proteins, and fats to stabilize blood sugar levels.
Physical activity: As tolerated and approved by the obstetrician, helps with glucose control.
Regular medical checkups: Enhanced prenatal care with more frequent visits, fetal monitoring, and early screening for complications.

Dietary Guidance

Work with a registered dietitian to develop a meal plan that matches caloric and carbohydrate needs.
Emphasize non-starchy vegetables, lean proteins, whole grains, and healthy fats.
Frequent, small meals with controlled carbohydrate portions.
Close attention to timing and distribution of carbohydrate intake throughout the day.

Exercise Recommendations

Aim for at least 150 minutes per week of moderate-intensity exercise, as tolerated.
Options include walking, swimming, or prenatal yoga.
Always discuss physical activity plans with your healthcare provider before beginning or changing exercise routines.

Potential Complications During Pregnancy

Pregestational diabetes can increase health risks for both mother and baby, requiring ongoing vigilance.

Preeclampsia: Elevated risk of high blood pressure and protein in urine during pregnancy.
Preterm birth: Increased likelihood of early labor before 37 weeks.
Macrosomia: Babies with high birth weight, leading to delivery complications.
Congenital anomalies: Especially if blood sugars are poorly controlled in the first trimester.
Neonatal hypoglycemia: Infants may experience low blood sugar soon after delivery.
Increased risk of cesarean delivery due to fetal or maternal complications.
Exacerbation of maternal diabetic complications: Such as retinopathy or nephropathy in mothers with pre-existing issues.

With skilled care, most women with Class C diabetes can achieve healthy pregnancy outcomes.

Tips for a Healthy Pregnancy with Class C Diabetes

Begin pregnancy with as well-controlled blood glucose as possible (optimal A1c before conception).
See your obstetrician and endocrinologist frequently for monitoring and adjustment of care plans.
Use a glucose log or app to keep track of readings and share regularly with your care team.
If using insulin, adjust dosages promptly with the guidance of your healthcare provider.
Attend all scheduled prenatal appointments for labs, ultrasounds, and fetal assessments.
Take prescribed prenatal vitamins, especially folic acid, to reduce the risk of fetal neural tube defects.
Maintain a healthy lifestyle with regular meals, safe physical activity, and stress-reduction techniques.

Frequently Asked Questions (FAQs)

What distinguishes Class C diabetes from other pregestational diabetes classes?

Class C diabetes is diagnosed when diabetes began between ages 10 and 19 or has been present for 10 to 19 years without significant vascular complications. Other classes are defined by age at onset, disease duration, and the presence of complications such as kidney or eye disease.

Is a pregnancy with Class C diabetes considered high-risk?

Yes. All pregnancies in people with pregestational diabetes are considered high-risk due to increased chances of complications affecting both the parent and the baby. Close monitoring and specialized prenatal care are needed.

Can pregestational diabetes affect the baby’s future health?

Children born to parents with diabetes have a higher lifetime risk of developing diabetes and metabolic conditions, particularly if maternal blood glucose is poorly controlled during pregnancy.

Can you manage Class C diabetes without insulin during pregnancy?

Some individuals with type 2 diabetes may initially manage with oral medications, but most with Class C diabetes, especially type 1 diabetes, require insulin for optimal control during pregnancy due to changing hormonal needs.

Final Thoughts and Resources

Class C diabetes in pregnancy requires a multidisciplinary approach involving endocrinologists, obstetricians, dietitians, and sometimes additional specialists. With proactive monitoring, individualized treatment, and support, women with Class C diabetes can experience healthy pregnancies and deliveries.

Schedule preconception counseling if possible to review diabetic management before becoming pregnant.
If you have questions about diabetes or pregnancy, speak to your healthcare provider.
Seek support from diabetes educators and prenatal classes tailored to high-risk pregnancies.

This article is for informational purposes only and should not replace individualized medical advice. Always consult your healthcare team for diagnosis and treatment recommendations.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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