---
title: Gestational Diabetes Management
description: A comprehensive clinical reference on the diagnosis, treatment, and monitoring of gestational diabetes.
keywords: [gestational diabetes, pregnancy, insulin, oral antihyperglycemic agents, fetal monitoring]
category: clinical
---

## Definition and Diagnostic Criteria

Gestational diabetes mellitus (GDM) is defined as glucose intolerance with onset or first recognition during pregnancy. The American Diabetes Association (ADA) recommends universal screening for GDM at 24-28 weeks gestation using a 75g oral glucose tolerance test (OGTT). Diagnostic criteria for GDM include:

- Fasting plasma glucose ≥ 92 mg/dL (5.1 mmol/L)
- 1-hour plasma glucose ≥ 180 mg/dL (10.0 mmol/L) 
- 2-hour plasma glucose ≥ 153 mg/dL (8.5 mmol/L)

Meeting one or more of these thresholds on the 75g OGTT confirms the diagnosis of GDM.

## Maternal and Fetal Risks

Uncontrolled gestational diabetes can lead to significant maternal and fetal complications. Maternal risks include an increased likelihood of preeclampsia, cesarean delivery, and future development of type 2 diabetes. Fetal risks include macrosomia, birth injuries, respiratory distress syndrome, and neonatal hypoglycemia. Effective management of GDM is crucial to mitigate these adverse outcomes.

## Treatment Approach

The primary goals of GDM management are to maintain euglycemia and prevent maternal/fetal complications. This is typically achieved through a combination of lifestyle modifications and pharmacologic therapy.

### Lifestyle Interventions
All women with GDM should receive medical nutrition therapy, including:
- Carbohydrate counting and distribution throughout the day
- Emphasis on high-fiber, low-glycemic index foods
- Calorie goals individualized based on pre-pregnancy BMI

Regular moderate-intensity exercise (e.g. 30 min/day, 5 days/week) is also recommended as tolerated.

### Pharmacologic Therapy
If lifestyle modifications alone are insufficient to achieve glycemic targets, pharmacologic therapy is indicated. First-line agents include:

- Metformin: Start 500-1000 mg twice daily, titrate to max 2000 mg/day
- Insulin: Basal-bolus regimen, starting doses 0.7-1.0 units/kg/day

For women with contraindications or intolerance to metformin or insulin, other options include:

- Glyburide: Start 2.5-5 mg daily, titrate to max 20 mg/day
- Liraglutide: Start 0.6 mg daily, titrate to max 1.8 mg/day

Combination therapy with multiple agents may be required in some cases to achieve glycemic control.

## Glycemic Monitoring and Targets

Optimal glycemic control is essential to mitigate maternal and fetal risks. Self-monitoring of blood glucose (SMBG) is recommended, with the following targets:

- Fasting: 95 mg/dL (5.3 mmol/L)
- 1-hour postprandial: 140 mg/dL (7.8 mmol/L) 
- 2-hour postprandial: 120 mg/dL (6.7 mmol/L)

In addition, periodic measurement of glycated hemoglobin (HbA1c) can provide insight into overall glycemic control, with a target of <6.5%.

## Fetal Monitoring

Close fetal monitoring is crucial in women with GDM to assess for potential complications. This includes:

- Ultrasound assessment of fetal growth and amniotic fluid volume every 4 weeks
- Non-stress testing and biophysical profile starting at 32 weeks gestation
- Evaluation for shoulder dystocia risk factors, such as estimated fetal weight >4500 g

Timing and mode of delivery should be individualized based on glycemic control, fetal growth, and other obstetric factors.

## Special Considerations

### Preexisting Diabetes
Women with preexisting type 1 or type 2 diabetes who become pregnant require particularly close monitoring and management. Insulin regimens may need to be adjusted, and screening for diabetic complications (retinopathy, nephropathy, neuropathy) should be performed.

### Postpartum Care
After delivery, women with GDM should undergo a 75g OGTT 4-12 weeks postpartum to screen for persistent dysglycemia. Those with persistent hyperglycemia should be managed according to the ADA's Standards of Medical Care in Diabetes.

### Breastfeeding
Breastfeeding is strongly encouraged for women with GDM, as it may help reduce the risk of future type 2 diabetes. Insulin requirements may need to be adjusted during the postpartum period to account for the increased insulin sensitivity associated with breastfeeding.

## Conclusion

Effective management of gestational diabetes is crucial to optimize maternal and fetal outcomes. A multifaceted approach incorporating lifestyle modifications, pharmacologic therapy, glycemic monitoring, and fetal surveillance is essential. Individualized care and close collaboration between the patient, obstetrician, and endocrinologist are key to successful GDM management.