Efficacy of lidocaine local anesthesia on pain perception during amniocentesis: a meta-analysis of randomized controlled trials

Objective: To evaluate the efficacy of lidocaine local analgesia on maternal pain reduction during amniocentesis.
Methods: PubMed, Scopus, Web of Science, and CENTRAL databases were searched from inception and updated in July 2022. The included randomized controlled trials (RCTs) were evaluated for risk of bias via the Cochrane tool. The primary outcome was pain perception using the 10-cm visual analogue scale (VAS), and summarized as mean difference (MD) with 95% confidence interval (CI) in a random-effects model. Subgroup analysis was done according to the mode of administration. Meta-analysis was done via Review Manager software.
Results: We included five RCTs totaling 1004 women; of these, 502 patients were allocated to the lidocaine group, and 502 patients were allocated to the control group. Overall, there was no significant difference between both groups (n=5 RCTs, MD=-0.21, 95% CI [-0.48, 0.07], p=0.80). The pooled analysis was homogeneous (Chi-square p=0.13, I-square=43%). Subgroup analysis according to the mode of administration showed that pain perception was not significantly different between both groups when lidocaine was used as injection (n=3 RCTs, MD=-0.26, 95% CI [-0.76, 0.23], p=0.29) or non-injection (n=2 RCTs, MD=-0.18, 95% CI [-0.55, 0.18], p=0.33). The pooled analyses were heterogeneous (Chi-square p=0.05, I-square=66%) and homogeneous (Chi-square p=0.27, I-square=19%), respectively.
Conclusion: There was no significant difference concerning pain perception between the lidocaine local anesthesia group and the control group. The majority of women reported just minimal discomfort during amniocentesis. Counseling should educate patients that the pain they might experience during amniocentesis is comparable to venous blood sampling.