What is the most appropriate next step in managing a patient in labor at 34 weeks gestation with a dilated cervix, intact membranes, and variable decelerations on cardiotocography?

Management of Preterm Labor at 34 Weeks with Active Labor

The most appropriate next step is to administer antenatal corticosteroids (betamethasone 12 mg IM × 2 doses, 24 hours apart) and allow labor to progress to vaginal delivery, as this patient meets criteria for late preterm steroid administration and shows reassuring fetal status despite variable decelerations. 1

Rationale for Corticosteroid Administration

This patient precisely meets the ALPS trial inclusion criteria for late preterm corticosteroid administration 1:

• Singleton pregnancy at 34 0/7 weeks gestation 1
• Cervix 4 cm dilated (≥3 cm meets threshold) 1
• High probability of delivery within 7 days given active labor with strong, regular contractions (4 in 10 minutes) 1

The Society for Maternal-Fetal Medicine strongly recommends (GRADE 1A) offering betamethasone to patients meeting these exact criteria, as it reduces neonatal respiratory morbidity and NICU admissions 1. Even though delivery may occur in <12 hours, corticosteroids should still be considered (GRADE 2C) as some benefit accrues even with abbreviated exposure 1.

Why NOT the Other Options

A. Cesarean Section - Inappropriate

• Variable decelerations alone do not mandate cesarean delivery 2
• The CTG shows reassuring features: baseline 110 bpm (normal), present accelerations, and good variability 2
• Variable decelerations are common (occurring in many laboring patients) and only concerning when accompanied by "hypoxic components" such as tachycardia, fixed baseline, or slow recovery 2
• This patient has none of these worrisome features 2
• Cesarean section is reserved for non-reassuring fetal status with concerning patterns, not isolated variable decelerations with otherwise normal tracing 2

B. Forceps Delivery - Inappropriate

• Station is -3 (high in pelvis), making instrumental delivery technically impossible and dangerous 3
• Forceps require engagement of the fetal head (at least 0 station or below) 3
• Attempting forceps at -3 station risks severe maternal and fetal trauma 3

C. Rupture Membranes - Contraindicated

• Artificial rupture of membranes (AROM) increases the risk of FHR abnormalities, particularly prolonged decelerations in the first 15 minutes post-rupture 4
• This patient already has variable decelerations; AROM would likely worsen the CTG pattern 4
• With vertex at -3 station and intact membranes, AROM increases cord prolapse risk 4
• No indication exists to artificially rupture membranes - labor is already progressing adequately with strong, regular contractions 4

D. Tocolytics - Inappropriate

• Tocolytics are contraindicated in active labor with 4 cm dilation 5
• The goal of tocolytics is to delay delivery 48-72 hours to allow corticosteroid administration 5
• This patient is already in established active labor with regular, strong contractions and significant cervical change 5
• Attempting to stop labor at this stage is futile and delays appropriate management 5

Optimal Management Algorithm

Immediate actions:

1. Administer first dose of betamethasone 12 mg IM immediately 1
2. Continue continuous fetal monitoring given variable decelerations 2
3. Allow labor to progress naturally - no intervention needed for membrane rupture 4
4. Prepare for vaginal delivery as fetal status is reassuring 2

Monitoring parameters:

• Watch for development of "hypoxic components" with variable decelerations: tachycardia, loss of variability, slow recovery, or late decelerations 2
• If these develop, consider expedited delivery 2
• Current pattern (good variability, accelerations present, baseline normal) is reassuring despite variable decelerations 2

Additional considerations at 34 weeks:

• Magnesium sulfate for neuroprotection is NOT indicated - this is only recommended before 32 weeks gestation 5, 6
• Neonatal team should be notified of impending preterm delivery 1
• Monitor for neonatal hypoglycemia post-delivery, as this is more common after late preterm steroid exposure (though typically mild and self-limited) 1

Critical Clinical Pearls

Variable decelerations are NOT automatically pathologic - they represent cord compression and are extremely common in labor 2. The key is assessing the overall CTG pattern: this patient has reassuring baseline, variability, and accelerations, making intervention unnecessary 2.

The 34-week threshold is critical - this is the exact gestational age where late preterm steroids provide maximum benefit with minimal risk 1. Missing this opportunity would increase neonatal respiratory morbidity 1.