Peripheral Nerve Blocks and Fascial Plane Blocks in Labor: Expert Evidence-Based Perspectives

The World Health Organization (WHO) designates epidural analgesia as the “gold standard” for labor pain relief.1 However, inserting epidurals can be challenging or contraindicated in certain situations (eg, thrombocytopenia, coagulopathy). Additional comorbidities may preclude neuraxial techniques, so the need for alternative methods becomes more pressing. Historically, pudendal nerve block (PNB) and paracervical block (PCB) were commonly used, but their use has declined. Recently, there has been growing interest in fascial plane blocks (FPBs), including the ultrasound-guided quadratus lumborum block (QLB) and erector spinae plane block (ESPB). We are not aware of any systematic reviews evaluating the safety or effectiveness of these blocks, and their clinical niche to date seems to lack expert consensus. Here we address this gap by offering our expert opinion, as based on a systematic review of the literature that accompanies the article (Supplementary Digital Content, https://links.lww.com/AA/F693). SUMMARY OF FINDINGS A detailed description of the methodology used for the literature review is available in Supplementary Digital Content, https://links.lww.com/AA/F693. This considers relevant studies involving laboring women aged over 18 years, who received peripheral nerve blocks (PNBs) or FPBs. The primary outcomes evaluated in the studies were maternal satisfaction (pain relief and opioid use). Secondary outcomes included any type of maternal or fetal periprocedural complication related to the analgesic technique used. Randomized clinical trials (RCTs), review, and observational studies on the topic of PCB and PNB were included, and given the limited availability of high-level evidence, we also included case reports, case series, and letters to the editor. A total of 12,575 articles were initially identified, which, after screening and exclusion criteria, left just 16 studies for consideration2–17; details from each included study are summarized in the Table. Table. - Summary of Included Studies Grouped by Block Type Author (year) Study design Interventions Sample Size Outcome Effect size Complications PCB Jensen et al(1984)4 RCT PCB 12 mL of 0.25% Bupivacaine 55 Labor pain reliefNeonatal well-being assessed with Apgar score (after 1 and 5 minutes) PCB provided significantly better pain relief (p