In a 22-year-old primigravida with type 1 diabetes at 32 weeks gestation presenting with regular painful contractions and a closed cervix, what is the most appropriate antenatal management?

Management of Preterm Labor at 32 Weeks in a Type 1 Diabetic Patient

The most appropriate management is steroids, additional insulin, and tocolytic agent (Option D). This patient requires all three interventions simultaneously: antenatal corticosteroids to accelerate fetal lung maturity, insulin dose adjustments to counteract steroid-induced hyperglycemia, and tocolytic therapy to delay delivery long enough for steroids to take effect.

Rationale for Combined Therapy

Antenatal Corticosteroids Are Mandatory

• A single course of corticosteroids is the standard of care for all pregnant women between 24 0/7 and 33 6/7 weeks of gestation who are at risk of preterm delivery within 7 days, regardless of membrane rupture status or fetal number 1.
• Betamethasone (two doses of 12 mg intramuscularly, 24 hours apart) is the preferred agent and has been shown to reduce neonatal respiratory distress syndrome, intraventricular hemorrhage, and neonatal mortality 2, 1.
• The benefit of corticosteroids is maximized when delivery occurs between 24 hours and 7 days after administration, making tocolysis essential to achieve this therapeutic window 1.

Insulin Adjustment Is Critical in Diabetic Patients

• Betamethasone causes significant hyperglycemia in pregnant women with diabetes, with 92% of diabetic patients developing blood glucose levels ≥140 mg/dL and 84% reaching ≥160 mg/dL 3.
• Women with pre-existing type 1 diabetes require insulin dose adjustments within 6 hours of steroid administration to prevent severe hyperglycemia and diabetic ketoacidosis 3.
• Pregnancy is a ketogenic state, and women with type 1 diabetes are at risk for diabetic ketoacidosis at lower blood glucose levels than in the nonpregnant state 4, 5.
• Close glucose monitoring (4–6 times daily) and proactive insulin titration are mandatory during and after steroid administration 6.

Tocolytic Therapy Provides the Time Window for Steroid Efficacy

• Tocolytic agents are effective in stopping uterine contractions and temporarily delaying delivery for 48–72 hours, which is precisely the time needed for corticosteroids to achieve maximal fetal benefit 7.
• The primary rationale for tocolysis in this scenario is not to prevent preterm birth per se, but to delay delivery long enough to administer corticosteroids and allow them to take effect 7.
• Magnesium sulfate is recommended as first-line tocolytic therapy due to its superior safety profile compared to beta-mimetics, particularly in diabetic patients 7.

Clinical Algorithm

Immediate Actions (Within 1 Hour)

• Administer first dose of betamethasone 12 mg intramuscularly 2, 1.
• Initiate tocolytic therapy with intravenous magnesium sulfate to achieve uterine quiescence for 48–72 hours 7.
• Increase basal insulin dose by 10–20% immediately and prepare for further escalation 6.
• Begin capillary blood glucose monitoring every 2–4 hours for the first 24 hours, then every 4–6 hours 3.

24-Hour Management

• Administer second dose of betamethasone 12 mg intramuscularly 2, 1.
• Titrate insulin upward by 2–4 units every 2–3 days based on glucose values, targeting fasting glucose 70–95 mg/dL and 1-hour postprandial <140 mg/dL 4, 6.
• Continue tocolysis for a total of 48 hours if uterine contractions persist 7.

48–72 Hour Window

• Discontinue tocolytic therapy once the 48-hour steroid window has passed and uterine activity has ceased 7.
• Maintain intensive glucose monitoring for at least 3 days after steroid administration, as hyperglycemia peaks during this period 3.
• Continue elevated insulin doses for approximately one week, as 35% of non-diabetic women and 49% of diabetic women require ongoing insulin adjustments beyond the acute steroid period 3.

Critical Pitfalls to Avoid

• Never administer corticosteroids without concurrent insulin adjustment in type 1 diabetic patients—this is the most common cause of steroid-induced diabetic ketoacidosis 3.
• Do not use beta-mimetic tocolytics (e.g., terbutaline) in diabetic patients, as they worsen hyperglycemia and increase cardiovascular complications 7.
• Avoid prolonged tocolysis beyond 48–72 hours, as it does not reduce preterm birth rates and increases maternal and fetal morbidity 7.
• A closed cervix does not exclude the need for intervention—regular painful contractions at 32 weeks constitute threatened preterm labor requiring full treatment 1.
• Do not delay steroid administration while "optimizing" glucose control first—the two interventions must occur simultaneously, with insulin adjusted proactively 3.

Why Other Options Are Inadequate

• Option A (Steroids alone) ignores the predictable and severe hyperglycemia that will occur in a type 1 diabetic patient, risking diabetic ketoacidosis and stillbirth 3.
• Option B (Tocolytic and steroids) fails to address steroid-induced hyperglycemia, which occurs in 92% of diabetic patients and requires immediate insulin adjustment 3.
• Option C (Insulin and steroids) omits tocolysis, eliminating the 48–72 hour window needed for corticosteroids to achieve maximal fetal lung maturation 7, 1.