What are the management options for an unfavorable fetal lie, such as a transverse lie, especially after 36 weeks of gestation?

Management of Unfavorable Fetal Lie After 36 Weeks

For transverse lie after 36 weeks of gestation, cesarean delivery is the definitive management, as the risk of complications increases significantly as term approaches, with persistence rates reaching 11.8% at 36-40 weeks. 1

Primary Management Approach

Cesarean delivery should be performed without delay once transverse lie is confirmed at or beyond 36 weeks, as this presentation carries high rates of maternal and perinatal complications if labor ensues. 2

• Emergency cesarean section is required in approximately 92% of cases presenting in labor with transverse lie 2
• The procedure should be performed in a facility well-equipped for cesarean delivery and potential complications 2
• Maternal positioning in left lateral decubitus or left pelvic tilt is essential during any procedure to prevent aortocaval compression and maintain placental perfusion 3

External Cephalic Version as an Alternative

External cephalic version (ECV) may be attempted before labor onset or in early labor with intact membranes as an alternative to routine cesarean delivery 4, 5:

• Success rates of 83% for conversion to longitudinal lie have been reported when performed under tocolysis with intact membranes 5
• When successful, ECV can reduce cesarean section rates by approximately 50% 5
• The procedure requires sonographic confirmation of fetal position, informed consent, and should be performed with tocolysis 5
• ECV is contraindicated with ruptured membranes, placental abruption, or imminent birth 3

Risk Factors and Antenatal Considerations

Key predisposing factors that should be identified during antenatal care include 4, 1, 2:

• Placenta previa or low-lying placenta (present in 29.3% overall and 35.7% of persistent cases) 1
• Multiparity 4
• Polyhydramnios 4
• Fetal and uterine anomalies 4
• Previous pregnancy affected by malpresentation 4

Timing Considerations

• Most transverse lies discovered before 36 weeks are transient and fortuitous, with only 2.6% persisting in the 20-25 week group 1
• The likelihood of persistence increases dramatically as term approaches, making intervention after 36 weeks increasingly urgent 1
• Early diagnosis during the antenatal period allows for elective delivery planning and reduces complications 2

Maternal and Fetal Risks

Transverse lie in labor is associated with 2:

• High rates of maternal morbidity including hemorrhage, infection, and difficult surgery
• Maternal mortality (documented in cases with delayed intervention) 2
• Significant perinatal morbidity with stillbirth rates and neonatal intensive care admissions 2
• Excellent neonatal outcomes when managed appropriately with timely intervention 5

Critical Pitfalls to Avoid

• Delaying cesarean delivery once transverse lie is confirmed at term, as complications escalate rapidly once labor begins 2
• Attempting vaginal delivery or expectant management beyond 36 weeks 1, 2
• Failing to identify associated placenta previa or other anatomic abnormalities that preclude ECV 1
• Performing procedures with the patient in supine position after 20 weeks, risking supine hypotension syndrome 3