***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Background Although medical interventions play an important role in preserving lives and maternal comfort they have become increasingly routine in normal childbirth . This may increase the risk of associated complications and a less satisfactory birth experience . Antenatal hypnosis is associated with a reduced need for pharmacological interventions during childbirth . This trial seeks to determine the efficacy or otherwise of antenatal group hypnosis preparation for childbirth in late pregnancy . Methods / design A single centre , r and omised controlled trial using a 3 arm parallel group design in the largest tertiary maternity unit in South Australia . Group 1 participants receive antenatal hypnosis training in preparation for childbirth administered by a qualified hypnotherapist with the use of an audio compact disc on hypnosis for re-enforcement ; Group 2 consists of antenatal hypnosis training in preparation for childbirth using an audio compact disc on hypnosis administered by a nurse with no training in hypnotherapy ; Group 3 participants  continue with their usual preparation for childbirth with no additional intervention . Women > 34 and < 39 weeks gestation , planning a vaginal birth , not in active labour , with a singleton , viable fetus of vertex presentation , are eligible to participate . Allocation concealment is achieved using telephone r and omisation . Participants assigned to hypnosis groups commence hypnosis training as near as possible to 37 weeks gestation . Treatment allocations are concealed from treating obstetricians , anaesthetists , midwives and those personnel collecting and analysing data . Our sample size of 135 women/group gives the study 80 % power to detect a clinical ly relevant fall of 20 % in the number of women requiring pharmacological analgesia – the primary endpoint . We estimate that approximately 5–10 % of women will deliver prior to receiving their allocated intervention . We plan to recruit 150 women/group and perform sequential interim analyses when 150 and 300 participants have been recruited . All participant data will be analysed , by a research er blinded to treatment allocation , according to the " Intention to treat " principle with comprehensive pre-planned cost- benefit and subgroup analyses . Discussion If effective , hypnosis would be a simple , inexpensive way to improve the childbirth experience , reduce complications associated with pharmacological interventions , yield cost savings in maternity care , and this trial will provide evidence to guide clinical practice BACKGROUND The use of negative words , such as ' sting ' and ' pain ' , can increase patient pain and anxiety . We aim ed to determine how pain scores compare with comfort scores and how the technique of pain assessment affects patient perceptions and experiences after operation . METHODS After Caesarean section , 300 women were r and omized before post-anaesthesia review . Group P women were asked to rate their pain  on a 0 - 10-point verbal numerical rating scale ( VNRS ) , where ' 0 ' was ' no pain ' and ' 10 ' was ' worst pain imaginable ' . Group C women were asked to rate  comfort  on a 0 - 10-point VNRS , where ' 0 ' was ' no comfort ' and ' 10 ' was ' most comfortable ' . All women were asked whether the Caesarean wound was bothersome , unpleasant , associated with tissue damage , and whether additional analgesia was desired . RESULTS The median ( inter-quartile range ) VNRS pain scores was higher than inverted comfort scores at rest , 2 ( 1 , 4 ) vs 2 ( 0.5 , 3 ) , P=0.001 , and movement , 6 ( 4 , 7 ) vs 4 ( 3 , 5 ) , P<0.001 . Group P women were more likely to be bothered by their Caesarean section , had greater VNRS ' Bother ' scores , 4 ( 2 , 6 ) vs 1 ( 0 , 3 ) , P<0.001 , perceived postoperative sensations as ' unpleasant ' [ relative risk ( RR ) 3.05 , 95 % confidence interval ( CI ) 2.20 , 4.23 ] , P<0.001 , and related to tissue damage rather than healing and recovery ( RR 2.03 , 95 % CI 1.30 , 3.18 ) , P=0.001 . Group P women were also more likely to request additional analgesia ( RR 4.33 , 95 % CI 1.84 , 10.22 ) , P<0.001 . CONCLUSIONS Asking about pain and pain scores after Caesarean section adversely affects patient reports of their postoperative experiences British physician , Dr. Grantly Dick-Read , was the first to suggest the “ fear-tension-pain ” cycle in his work Natural Childbirth ( 1933 ) . As a result of his underst and ing of how this cycle affected birthing , he recommended women prepare for childbirth . Research studies from around the world have shown that the use of hypnosis for childbirth results in : ∗ shorter labors ∗ reduced use of pain medication ∗ higher Apgar scores ∗ reduced cesarean and forceps Background The neural mechanisms underlying the modulation of pain perception by hypnosis remain obscure . In this study , we used positron emission tomography in 11 healthy volunteers to identify the brain areas in which hypnosis modulates cerebral responses to a noxious stimulus . Methods The protocol used a factorial design with two factors : state ( hypnotic state , resting state , mental imagery ) and stimulation ( warm non-noxious vs. hot noxious stimuli applied to right thenar eminence ) . Two cerebral blood flow scans were obtained with the 15O-water technique during each condition . After each scan , the subject was asked to rate pain sensation and unpleasantness . Statistical parametric mapping was used to determine the main effects of noxious stimulation and hypnotic state as well as state-by-stimulation interactions ( i.e. , brain areas that would be more or less activated in hypnosis than in control conditions , under noxious stimulation ) . Results Hypnosis decreased both pain sensation and the unpleasantness of noxious stimuli . Noxious stimulation caused an increase in regional cerebral blood flow in the thalamic nuclei and anterior cingulate and insular cortices . The hypnotic state induced a significant activation of a right-sided extrastriate area and the anterior cingulate cortex . The interaction analysis showed that the activity in the anterior (mid-)cingulate cortex was related to pain perception and unpleasantness differently in the hypnotic state than in control situations . Conclusions Both intensity and unpleasantness of the noxious stimuli are reduced during the hypnotic state . In addition , hypnotic modulation of pain is mediated by the anterior cingulate cortex Negative or harsh words such as ‘ pain ’ and ‘ sting ’ used to describe sensations prior to potentially painful procedures have been shown to increase pain . We aim ed to determine whether the reporting of pain and its severity is affected by the way it is assessed during anaesthesia follow-up after caesarean section . Following caesarean section , 232 women were r and omised prior to post-anaesthesia review . Group N participants were asked questions containing the negative word ‘ pain ’ , “ Do you have any pain ? ” and then asked to rate it on a 0 to 10 point Verbal Numerical Rating Scale . Group P participants were asked questions using more positive words , “ How are you feeling ? ” and “ Are you comfortable ? ” . Data are presented as median , interquartile range . In Group N , 63 participants ( 54.3 % ) reported pain compared with only 28 participants ( 24.1 % ) in Group P ( P < 0.001 ) . There were no significant differences between groups for Verbal Numerical Rating Scale at rest : Group N 2 ( 0 to 3 ) vs Group P 1 ( 0 to 4 ) ; P=0.97 , or Verbal Numerical Rating Scale with movement , Group N 5 ( 3 to 6 ) vs Group P 5 ( 3 to 6.3 ) ; P=0.90 . The assessment of pain after caesarean section , using more positive words , decreases its incidence but does not affect its severity when measured by pain scores . Words that focus the patient on pain during its assessment may lead some to interpret sensations as pain which they might not do otherwise . These findings may have important implication s when assessing and research ing postoperative pain The benefits of hypnotic analgesia as an adjunct to childbirth education were studied in 60 nulliparous women . Subjects were divided into high and low hypnotic susceptibility groups before receiving 6 sessions of childbirth education and skill mastery using an ischemic pain task . Half of the Ss in each group received a hypnotic induction at the beginning of each session ; the remaining control Ss received relaxation and breathing exercises typically used in childbirth education . Both hypnotic Ss and highly susceptible Ss reported reduced pain . Hypnotically prepared births had shorter Stage 1 labors , less medication , higher Apgar scores , and more frequent spontaneous deliveries than control Ss ' births . Highly susceptible , hypnotically treated women had lower depression scores after birth than women in the other 3 groups . We propose that repeated skill mastery facilitated the effectiveness of hypnosis in our study Comparaison de 29 primipares preparees avec un entrainement d'auto-hypnose et 36 preparees de facon traditionnelle . Les result ats indiquent que l'hypnose n'est pas significativement efficace en tant que method e d'analgesie , qu'elle donne cependant une amelioration de l'experience de l'accouchement , et qu'elle est peut-etre une cause de prolongement de la 
    Output:
    
There are still only a small number of studies assessing the use of hypnosis for labour and childbirth .