Does local anesthesia decrease pain perception in women undergoing amniocentesis? The efficacy of lidocaine-prilocaine cream to reduce pain in genetic amniocentesis. Reducing pain with genetic amniocentesis-A randomized trial of subfreezing versus room temperature needles. Does local anesthesia at mid-trimester amniocentesis decrease pain experience? A randomized trial in 220 patients.
The null hypothesis is that local anesthesia does not decrease pain perception during amniocentesis.
                We performed a prospective randomized study comparing local anesthesia (1% lidocaine) with no anesthesia before amniocentesis in a racially diverse population. Immediately after the procedure, subjects were asked to assess their pain using both a Visual Analogue Scale and a 101-point Numerical Rating Scale.
                Two hundred four women were enrolled; 101 women received local, 102 women received no local, and 1 woman declined the amniocentesis after randomization. There was no difference in pain perception between the 2 groups as measured by either the visual analogue scale or the numeric rating scale (P = .28 and .18 respectively). The correlation coefficient between the 2 pain scales was strong with 0.86 for the local group and 0.92 for the no local group, (P < .001).
                Administration of local anesthesia before amniocentesis does not decrease maternal pain perception. Evaluate whether local anesthesia by lidocaine-prilocaine cream decreases maternal pain during mid-trimester genetic amniocentesis.
                This randomized controlled study of mid-trimester genetic amniocentesis was conducted between 1 October 2006 and 30 April 2007. Pregnant women were randomized to receive lidocaine-prilocaine cream or placebo cream 30 minutes prior to amniocentesis. Patients, blinded to allocation, recorded anticipated and actual pain before and after the procedure. The visual analog score (VAS) was evaluated, using a 0-10 scale.
                One hundred and twenty women participated in the present study. Sixty women were randomized to lidocaine-prilocaine group. The two groups were similar with respect to clinical correlations and procedure characteristics. Anticipated pain was 6.1 +/- 2.0 in the lidocaine-prilocaine group and 6.3 +/- 2.3 in the placebo group (p = 0.61). Actual pain was 2.3 +/- 2.2 in the lidocaine-prilocaine group and 2.9 +/- 2.5 in the placebo group (p = 0. 16).
                Lidocaine-prilocaine cream does not decrease pain during mid-trimester genetic amniocentesis. To determine whether pain associated with second trimester genetic amniocentesis is decreased by using subfreezing rather than room temperature needles.
                Subjects were randomized to a -14 degrees C or room temperature (20-22 degrees C) 22-gauge spinal needle. Patients, blinded to allocation, recorded anticipated and actual pain before and after the procedure, respectively, using a 0-10 visual analog scale with 0 = no pain and 10 = excruciating pain.
                Thirty-three subjects were randomized to room temperature and 29 subjects to subfreezing needles. Anticipated pain was similar in room temperature, 5.1 +/- 1.7, and subfreezing groups, 4.9 +/- 2.0, respectively (p = 0.6). Actual pain was also similar in the room temperature, 3.6 +/- 2.0, and subfreezing groups, 2.8 +/- 2.0, respectively (p = 0.14). Similar numbers of subjects in the room temperature and subfreezing groups reported less actual pain (20 vs. 18), greater actual pain (4 vs. 4) or no difference in pain (9 vs. 5) than anticipated (p = 0.6).
                A subfreezing 22-gauge spinal needle does not decrease perceived pain associated with second trimester genetic amniocentesis. To evaluate whether local anesthesia decreases patients' pain experience during mid-trimester amniocentesis.
                In a randomized trial, one group did not receive local anesthesia while, in another group, lignocaine 1% was injected subcutaneously prior to amniocentesis. Five different scoring systems were used to evaluate patients' pain experience.
                Two hundred and twenty women entered the study: 114 received local anesthesia, while 106 did not. The mean (SD) Visual Analog Scale was 1.4 (1.5) on a 0-10 scale (range 0-7.6). Some 97% of patients described the procedure as not painful or bearable, 79% had expected the procedure to be more painful and 59% reported the amniocentesis to have a comparable discomfort as venous blood sampling; 98% of women declared they would undergo an amniocentesis again if indicated. There were no statistical differences between both randomization groups.
                Mid-trimester amniocentesis is not a painful procedure. Local anesthesia does not affect pain experience during amniocentesis.
In general, women who undergo amniocentesis could be informed that pain during procedure is minor and that there is currently insufficient evidence to support the use of local anaesthetics, leg rubbing or subfreezing the needle for pain reduction during procedure.