Why is dexamethasone (dexa) given to a delivery patient?

Why Dexamethasone is Given to Delivery Patients

Dexamethasone (or betamethasone) is administered to pregnant patients at risk of preterm delivery to accelerate fetal lung maturation and dramatically reduce neonatal respiratory distress syndrome, mortality, and severe respiratory complications. 1, 2, 3

Primary Indication: Fetal Lung Maturation in Preterm Delivery

The fundamental purpose is to prevent life-threatening respiratory complications in preterm infants by inducing surfactant production and structural lung development before birth. 4, 5

Standard Gestational Age Windows

For deliveries between 24 0/7 and 34 6/7 weeks:

• Betamethasone 12 mg intramuscularly, two doses 24 hours apart, is the preferred agent with strongest evidence. 3, 6
• Dexamethasone 12 mg intramuscularly, two doses 24 hours apart, is an acceptable alternative when betamethasone is unavailable. 2, 7
• This reduces neonatal mortality (odds ratio 0.60), respiratory distress syndrome (odds ratio 0.53), and intraventricular hemorrhage. 4

For late preterm deliveries between 34 0/7 and 36 6/7 weeks:

• Betamethasone 12 mg intramuscularly every 24 hours for 2 doses should be offered to singleton pregnancies at high risk of delivery within 7 days. 1, 2
• This reduces the need for respiratory support by 20% (relative risk 0.80) and severe respiratory morbidity by 33% (relative risk 0.67). 2, 6

Optimal Timing for Maximum Benefit

The critical window is delivery occurring 24 hours to 7 days after steroid administration. 2, 3, 6

• Maximum fetal lung maturation occurs when delivery happens within this timeframe. 6
• Benefits extend across all gestational ages within the recommended range and are not limited by fetal gender or race. 4

Specific Clinical Scenarios Requiring Steroids

High-risk criteria for late preterm administration (34-36 6/7 weeks):

• Preterm labor with intact membranes AND cervical dilation ≥3 cm or ≥75% effacement. 2
• Spontaneous rupture of membranes with expected delivery within 24 hours to 7 days. 2
• Planned preterm delivery for maternal/fetal indications (e.g., preeclampsia, gestational hypertension) with delivery anticipated between 24 hours and 7 days. 2

For deliveries <34 weeks with liver disease complications:

• High-dose dexamethasone or betamethasone should be given per national guidance when delivery is planned before 35 weeks for conditions like HELLP syndrome or acute fatty liver of pregnancy. 1
• Steroids are given solely for fetal lung maturation, NOT to improve maternal outcomes in HELLP syndrome. 1

Critical Contraindications

Absolute contraindication: Pregestational diabetes mellitus

• Antenatal corticosteroids significantly increase the risk of severe neonatal hypoglycemia in this population. 1, 2, 6
• This contraindication applies to both early and late preterm steroid administration. 6

Do NOT administer when:

• Low likelihood of delivery before 37 weeks of gestation exists. 1
• Patient has already received a prior course of antenatal corticosteroids in the late preterm period. 1
• Delivery should not be delayed to complete the steroid course when immediate delivery is medically indicated. 1, 6

Common Clinical Pitfalls to Avoid

Overly broad administration in late preterm period:

• The ALPS trial used stringent criteria (cervical dilation ≥3 cm), resulting in only 16.4% term delivery rate. 1
• In clinical practice, less discerning use dilutes the benefit by treating many patients who ultimately deliver at term. 1
• Select only patients truly at high risk of preterm delivery within 7 days. 1

Inappropriate repeat dosing:

• A single course is recommended; routine repeat or "rescue" courses are not advised. 3
• Avoid giving late preterm corticosteroids to patients who already received a course earlier in pregnancy. 1

High-dose dexamethasone regimens:

• High-dose dexamethasone (0.5 mg/kg per day) does not confer additional therapeutic benefit over lower doses and is not recommended for postnatal use. 1
• Recent evidence suggests 5 mg dexamethasone is noninferior to 6 mg for preventing respiratory distress syndrome in late preterm births. 8

Special Populations Requiring Clinical Judgment

Consider administration with shared decision-making for:

• Multiple gestations reduced to singleton on or after 14 0/7 weeks gestation. 2, 6
• Pregnancies with fetal anomalies. 2, 6
• Patients expected to deliver in <12 hours. 2, 6
• Late preterm twins at risk of delivery (guidelines not yet established; shared decision-making recommended). 1

Essential Patient Counseling

Patients must be thoroughly informed that:

• Short-term benefits are well-established (reduced respiratory morbidity and mortality). 1, 2
• Long-term neurodevelopmental risks remain uncertain, with ongoing studies evaluating outcomes at 6 years of age. 1, 2
• Repeated doses in pregnancy have been associated with neurocognitive and neurosensory disorders in offspring during childhood. 1

Monitoring Requirements

Neonatal hypoglycemia monitoring is essential:

• Betamethasone increases the risk of neonatal hypoglycemia, though 93% of cases resolve within 24 hours and are mild and self-limited. 3
• This is particularly critical in diabetic mothers, though corticosteroids are contraindicated in pregestational diabetes. 6