Analgesia for amniocentesis

In addition to concerns about the risks of miscarriage after amniocentesis, women are also concerned about pain during and after the procedure. Currently, approaches for analgesia can be categorised in two broad categories - non-pharmacological and pharmacological agents. Their effect, or lack of it, is most commonly evaluated with visual analogue scale (VAS).

We identified five studies (involving a total of 805 women) that evaluated effectiveness of analgesia for pain during amniocentesis. Types of analgesia included local anaesthetics (either injected (two studies, 423 women) or applied topically (one study, 120 women)); use of a subfreezing (-14°C) needle (one study, 62 women); and leg rubbing (one study, 200 women). We found no studies evaluating analgesia during chorionic villus sampling.

Each comparison failed to demonstrate positive affect on pain 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 this procedure.

Authors' conclusions: 

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.

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Background: 

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.

Objectives: 

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

Search strategy: 

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

Selection criteria: 

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.

Data collection and analysis: 

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

Main results: 

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).