Efficacy of cryoanalgesia in decreasing pain during second trimester genetic amniocentesis: a randomized trial

To evaluate the effectiveness of cryoanalgesia in decreasing the degree of pain sensation during second trimester genetic amniocentesis.

We performed a prospective randomized study comparing the anticipated and actual pain before and after second trimester genetic amniocentesis between pregnant women who received and did not receive cryoanalgesia. The pain was measured using the visual analog score (VAS), ranging from 0 to 10.

Three hundred and seventy-two pregnant women participated in our study. One hundred and eighty-four and 188 pregnant women were randomized to cryoanalgesia received and non-cryoanalgesia received groups, respectively. The pre-procedure anxiety mean VAS scores and the anticipated pain mean VAS scores between the groups were not significantly different (P = 0.25 and 0.18, respectively). The pre-procedure anxiety and the anticipated pain mean ± SD VAS scores in the cryoanalgesia and non-cryoanalgesia groups were 5.7 ± 0.37 vs. 8.0 ± 0.82 and 5.4 ± 1.34 vs. 5.6 ± 1.42, respectively. The post-procedure pain and anxiety mean VAS scores in the cryoanalgesia group were statistically less significant than those from the non-cryoanalgesia group (mean ± SD = 3.2 ± 1.60 and 3.8 ± 1.58, respectively, P = 0.004). Most pregnant women claimed to have experienced moderate pain and accepted to undergo a second trimester genetic amniocentesis again if indicated.

Cryoanalgesia is effective in decreasing the pain sensation and could be routinely applied to all pregnant women before the second trimester genetic amniocentesis.