Analgesia for amniocentesis or chorionic villus sampling

Besides risks of miscarriage, pregnant women undergoing amniocentesis or chorionic villus sampling (CVS) are also concerned about pain associated with these procedures. Currently, approaches to analgesia can be categorised in two broad categories - non-pharmacological and pharmacological agents.

To evaluate whether different methods of analgesia have any impact on pain reduction during amniocentesis or chorionic villus sampling (CVS).

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2011).

All randomised trials comparing different method of analgesia for amniocentesis or CVS. We also include trials with quasi-randomised designs, but analyse and report their results separately.

Both review authors assessed eligibility and trial quality and performed data extraction.

We included a total of five randomised studies (involving 805 women) evaluating different methods of analgesia for amniocentesis; there were no studies in women undergoing CVS.One RCT (N = 203) and one quasi-randomised study (N = 220) compared infiltrative local anaesthesia with no anaesthesia and found no statistical difference in experienced pain on the visual analogue scale (VAS) (mean differences (MD) -2.50 and 1.20; 95% confidence interval (CI) -6.98 to 1.98 and -2.67 to 5.07).One study (N = 200) compared light leg rubbing versus no intervention during amniocentesis and found no change in experienced anxiety (MD 0.2; 95% CI -0.63 to 1.03) or VAS pain score (MD 0.3; 95% CI -0.35 to 0.95) during amniocentesis.Another study with 62 patients did not find any benefit of using subfreezing temperature needle during amniocentesis in terms of decreased VAS pain score (MD -0.8; 95% CI -1.8 to 0.2). In addition, there was no difference between anticipated and actual pain (MD 0.4; 95% CI -0.82 to 1.62) (before/after comparison).There was also no difference in VAS pain scores in the study with 120 participants comparing lidocaine-prilocaine analgesic cream to placebo cream before amniocentesis (MD -0.6; 95% CI -1.44 to 0.24).

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.