Which of the following scenarios is most likely to be successful with a vaginal breech delivery: a primigravida (G1) at 38 weeks, spontaneous rupture of membranes without labor, estimated fetal weight 3800g; a multigravida (G2P1) at 38 weeks, latent labor, cervix 2cm, feet palpable; a primigravida (G1) at 41 weeks, cervix Bishop’s score 3, estimated fetal weight 3500g; or a multigravida (G3P2) at 38 weeks, frank breech, spontaneous labor, estimated fetal weight 3000g?

Vaginal Breech Delivery Success Factors

The G3P2 38 weeks, frank breech, spontaneous labor, estimated fetal weight 3000g scenario is most likely to be successful with a vaginal breech delivery. This scenario combines multiple favorable factors that optimize the chances of successful vaginal breech delivery while minimizing maternal and neonatal morbidity and mortality.

Analysis of Each Scenario

Most Favorable: G3P2 38 weeks, frank breech, spontaneous labor, EFW 3000g

• Multiparity: Previous successful deliveries (G3P2) indicate proven pelvic adequacy
• Frank breech presentation: Associated with better outcomes in vaginal delivery 1
• Spontaneous labor: Better indicator of uterine contractility and fetal accommodation to maternal pelvis 2
• Appropriate fetal weight: 3000g falls within the optimal range (2500-3500g) for vaginal breech delivery 1
• Term gestation: 38 weeks is optimal timing for delivery

Less Favorable: G2P1 38 weeks, latent labor, cervix 2 cm, feet palpable

• Multiparity is favorable
• However, complete breech (feet palpable) increases risk of cord prolapse (4.5% vs 0.3% in frank breech) 3
• Early labor stage (cervix 2cm) means higher chance of prolonged labor
• Latent labor rather than active spontaneous labor is less predictive of successful progression

Least Favorable: G1 38 weeks, spontaneous rupture of membranes without labor, EFW 3800g

• Primiparity (no proven pelvic adequacy)
• Ruptured membranes without labor increases risk of cord prolapse
• High estimated fetal weight (3800g) exceeds recommended range for vaginal breech delivery 1
• Lack of spontaneous labor is unfavorable

Least Favorable: G1 41 weeks, cervix Bishop's score 3, EFW 3500g

• Primiparity (no proven pelvic adequacy)
• Post-term pregnancy (41 weeks) increases risks
• Unfavorable cervix (Bishop score 3) suggests poor progress
• Upper limit of recommended fetal weight (3500g)
• No spontaneous labor

Key Factors for Successful Vaginal Breech Delivery

1. Parity: Multiparous women have demonstrated pelvic adequacy and typically have faster, more efficient labors

2. Type of breech presentation: Frank breech is most favorable due to:

   • Lower risk of cord prolapse compared to complete breech 3
   • Less need for forceps to the after-coming head (9.7% vs 16.2% in complete breech) 3

3. Labor status: Spontaneous labor is superior to induced labor or no labor because it:

   • Better indicates uterine contractility
   • Shows fetal accommodation to the maternal pelvis
   • Allows optimal monitoring with partograph 2

4. Fetal weight: Optimal range is 2500-3500g 1

   • Below 2500g: Higher risk of preterm complications
   • Above 3500g: Increased risk of dystocia and birth trauma

5. Gestational age: Term (37-40 weeks) is optimal

   • Preterm: Higher neonatal morbidity regardless of delivery mode
   • Post-term: Increased risks of fetal compromise

Clinical Implications

When considering vaginal breech delivery, a careful selection process should evaluate:

• Maternal factors: parity, pelvic adequacy, labor progress
• Fetal factors: type of breech, estimated weight, gestational age
• Intrapartum factors: spontaneous vs induced labor, membrane status

The G3P2 woman with frank breech in spontaneous labor with appropriate fetal weight represents the ideal candidate for successful vaginal breech delivery with minimal maternal and neonatal morbidity.

For safety, continuous fetal monitoring and availability of senior obstetrical expertise are essential for any attempted vaginal breech delivery 4.