Betamethasone in Preterm Labor at 34 Weeks
At 34 weeks gestation, administer betamethasone 12 mg intramuscularly as two doses 24 hours apart if the patient meets high-risk criteria for delivery within the next 7 days and before 37 weeks. 1, 2, 3
Specific High-Risk Criteria Required for Administration
You must verify that the patient meets at least one of these criteria before administering corticosteroids at 34 weeks:
- Preterm labor with intact membranes AND cervical dilation ≥3 cm OR cervical effacement ≥75% 3
- Spontaneous rupture of membranes 3
- Anticipated preterm birth for any obstetric indication (e.g., preeclampsia, fetal growth restriction, oligohydramnios) with planned delivery via induction or cesarean within 24 hours to 7 days 3
Absolute Contraindications
Do not administer betamethasone if the patient has pregestational diabetes mellitus due to markedly increased risk of severe neonatal hypoglycemia. 1, 2, 3 This is an absolute contraindication with GRADE 1C recommendation strength. 1
Do not administer if there is low likelihood of delivery before 37 weeks as potential harms outweigh benefits (GRADE 1B). 1, 3
Standard Dosing Protocol
- Betamethasone 12 mg intramuscularly, two doses given 24 hours apart 1, 2, 3
- Maximum benefit occurs when delivery happens 24 hours to 7 days after administration 2, 4
- A single course only—do not give routine repeat or "rescue" courses in the late preterm period (34-36 weeks) 2, 4
Clinical Benefits at This Gestational Age
- Reduces need for respiratory support by 20% (RR 0.80,95% CI 0.66-0.97) 2, 3
- Reduces severe respiratory morbidity by 33% (RR 0.67,95% CI 0.53-0.84) 2, 3
- Decreases respiratory distress syndrome by 29% (RR 0.71,95% CI 0.65-0.78) 3
Critical Pitfalls to Avoid
Overuse in low-risk patients: Only 16.4% of women who received late-preterm steroids in the ALPS trial ultimately delivered at term, highlighting the importance of strict patient selection. 3 Exposing term neonates to unnecessary steroids creates avoidable risks. 3
Delaying medically indicated delivery: Do not delay delivery to complete the steroid course if immediate delivery is medically necessary. 3
Use in diabetic patients: This significantly increases severe neonatal hypoglycemia and is contraindicated. 1, 2, 3
Neonatal Hypoglycemia Monitoring
- Neonatal hypoglycemia occurs more frequently after betamethasone exposure 3
- However, 93% of cases are mild, self-limited, and resolve within 24 hours 2, 3
- Infants who develop hypoglycemia after maternal steroids have lower likelihood of prolonged NICU stay (>3 days) 3
Mandatory Patient Counseling
You must provide comprehensive counseling regarding short-term neonatal benefits and uncertain long-term neurodevelopmental risks (GRADE 1C). 1, 3 Patients need to understand that while short-term respiratory benefits are well-established, long-term neurodevelopmental outcomes remain under investigation. 1, 3
Tocolysis Strategy
Tocolysis is not routinely indicated during steroid administration in the absence of active contractions, cervical shortening, or rupture of membranes. 5 Use tocolysis only if needed to prolong pregnancy for the 24-48 hours required to complete the steroid course and achieve maximum benefit.