From the Guidelines
Cesarean section is the recommended delivery method for a deflexed fetus in an arrested second stage of labor due to the increased risk of complications associated with forceps and vacuum extraction. A deflexed fetal head creates a larger presenting diameter, making vaginal delivery more difficult and increasing the risk of maternal trauma and fetal injury 1. Forceps delivery may be attempted in certain situations, but it carries significant risks, and the use of a single forceps as a lever to disimpact the head is considered dangerous 1. Vacuum extraction is typically contraindicated in deflexed presentations due to the potential for fetal scalp injuries and failed extraction 1.
Key Considerations
- The degree of deflexion, station of the presenting part, maternal pelvic adequacy, fetal size, maternal exhaustion, and fetal status should be taken into account when making a decision 1.
- Preparation should be made for immediate cesarean section if instrumental delivery is attempted and unsuccessful.
- Maternal risks of cesarean include surgical complications and longer recovery, while risks of instrumental delivery include perineal trauma, vaginal lacerations, and pelvic floor injury.
- The deflexed presentation itself increases mechanical difficulty for vaginal delivery, making cesarean section often the most prudent choice for both maternal and fetal safety.
Evidence-Based Recommendation
The most recent and highest quality study 1 supports the use of cesarean section as the safest option for delivery in cases of deflexed fetus in an arrested second stage of labor. This study highlights the importance of avoiding nonrecommended techniques, such as the use of a single forceps blade or ventouse, employed abdominally to assist delivery of an impacted fetal head at cesarean delivery. Instead, training should be accompanied by management algorithms with a sequential, structured, and flexible approach, and high-fidelity simulation and implementation of standardized care pathways are likely to represent the safest and most effective form of training.
From the Research
Delivery Methods for Deflexed Fetus in Arrested Second Stage of Labor
The best delivery method for a deflexed fetus in an arrested second stage of labor is a topic of ongoing research and debate. Several studies have investigated the outcomes of different delivery methods, including forceps, cesarean section (C-section), and vacuum extraction.
Comparison of Delivery Methods
- Forceps vs. Vacuum Extraction: According to 2, obstetrical forceps seem more efficient than vacuum extraction, but are associated with severe perineal tears.
- Cesarean Section: Studies have shown that cesarean delivery is associated with increased risk of maternal and perinatal morbidity and mortality, especially in low-resource settings 3.
- Vacuum Extraction: Vacuum extraction is recommended as the preferred mode of birth in both high-income and low- and middle-income countries to prevent unnecessary cesarean sections and reduce perinatal and maternal deaths 3.
Factors Influencing Delivery Method
- Fetal Head Deflexion: Sonographic diagnosis of fetal head deflexion is an independent risk factor for cesarean delivery, regardless of the occiput position 4.
- Arrested Second Stage of Labor: Prolonged second stage of labor is an important cause of maternal and perinatal morbidity and mortality, and the management of labor disorders consists of oxytocin administration, amniotomy, intrauterine pressure catheter use, and shared decision-making regarding proceeding with expectant management, operative vaginal delivery, or cesarean delivery 5.
Maternal and Neonatal Outcomes
- Maternal Complications: Uterine laceration and incision extension frequencies were lower in the standard vertex extraction method compared to push and reverse breech extraction methods 6.
- Neonatal Outcomes: Delivery-related neonatal injury was significantly more frequent in the reverse breech extraction method 6.