***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The maternal half-sitting and supine position during the second stage of fullterm labor was compared in 100 women who , after identical opening phases in  supine position  , r and omly delivered in half-sitting ( 50 degrees , n = 50 ) or supine position ( n = 50 ) . The whole duration of the second stage of labor or the time spent in active pushing did not differ between the groups .  Vacuum extraction  was needed twice ( 4 % ) in the group delivering in half-sitting and six times ( 12 % ) in the group delivering in supine position . Vaginal tear occurred in one mother in both groups . Early decelerations in fetal cardiotocography were seen 22 times in half-sitting and 14 times in supine group ( p less than 0.05 ) . However , late decelerations were seen in only one mother with half-sitting , as compared to five mothers with supine position . Four infants of mothers giving birth in supine position had 1 minute APGAR scores 7 or less , whereas all infants of mothers delivering in half-sitting position had APGAR scores higher than 7 . Subjectively the mothers liked more the half-sitting position . We conclude that a women can deliver in half-sitting position without maternal or fetal risks Two hundred ninety-four women were r and omly allocated to a group in which the use of a birthing stool ( experimental group ) or a conventional semirecumbent position ( control group ) was encouraged . The birthing stool was 32 cm high and allowed the parturient to sit upright and to squat . The husb and could sit close behind his wife and support her back . No differences were observed between the two groups regarding mode of delivery , length of the second stage of labor , oxytocin augmentation , perineal trauma , labial lacerations , or vulvar edema . Infant outcome measured by Apgar scores at 1 and 5 minutes postpartum and numbers of neonatal intensive care unit transfers was the same in both groups . Mean estimated blood loss and the number of mothers with a postpartum hemorrhage 600 ml or more were greater in the experimental group than in the control group . Women in the experimental group reported less pain during the second stage of labor , and they and their spouses were more satisfied with the birth position than were parents in the control group . Midwives were less satisfied with their working posture in the experimental group OBJECTIVE : To compare the outcomes of the current practice of liberally or routinely employing episiotomy to prevent perineal tears and pelvic floor relaxation ( control group ) to a policy of restricting episiotomy use to specific fetal and maternal indications ( experimental group ) . DESIGN : A r and omized controlled trial ( RCT ) . SETTING : Three university hospitals in Montreal . SUBJECTS : Seven hundred three low-risk women enrolled at 30 to 34 weeks of gestation were r and omized late in labor to the design ated trial arm , by parity , and followed up to 3 months postpartum . MAIN OUTCOME MEASURES : Antepartum and postpartum information on perineal trauma and pain , pelvic floor symptoms ( urinary incontinence ) , and sexual activity was collected through the use of st and ard question naires ; pelvic floor function was measured by electromyographic ( EMG ) perineometry . RESULTS : Restricting episiotomy use in primiparous women was associated with similar sutured perineal trauma to the liberal or routine approach . Multiparous women in the restricted episiotomy group more often gave birth with an intact perineum ( 31 % compared with 19 % , odds ratio ( OR ) = 1.85 , 95 % confidence interval ( CI ) = 1.09 to 3.16 ) . All but one 3rd/4th-degree perineal tear was associated with median episiotomy ( 46 of 47 in primiparous women and 6 of 6 among multiparous women ) . No difference between trial groups was found in postpartum perineal pain , antepartum and 3-month postpartum EMG perineometry , and urinary and pelvic floor symptoms . CONCLUSIONS : We found no evidence that liberal or routine use of episiotomy prevents perineal trauma or pelvic floor relaxation . Virtually all severe perineal trauma was associated with median episiotomy . Restriction of episiotomy use among multiparous women result ed in significantly more intact perineums and less perineal suturing Women throughout the ages have preferred to be delivered with their trunks vertical and most delivery positions illustrated in historical texts show birth in an upright posture with abducted thighs . A consumer attitude study in our hospital showed that patients have considerable interest in alternative birth positions . Squatting has been advocated to prevent caval compression , increase the diameter of the pelvic outlet and , perhaps with least justification , to enlist the force of gravity and thereby facilitate maternal expulsive effort . Despite the extensive literature advocating squatting birth , the suggested advantages of this method have not been examined in any formal , let alone unbiased study . We therefore conducted a r and omised trial to examine the effect of squatting on the duration of second stage of labour , the duration of pushing , and several other variables One hundred eighteen nulliparous patients delivered under conduction anesthesia who met the st and ard criteria for low forceps delivery were r and omly assigned to one of three groups to be delivered by low Tucker-McLane forceps , Silastic vacuum extraction system , or Mityvac vacuum extractor .  Significant maternal soft tissue trauma was identified in 48.9 % of the forceps group , 36.1 % of the Silastic group , and 21.6 % of the Mityvac group . Superficial fetal scalp changes were found in 71 % of the forceps group , 44 % of the Silastic group , and 46 % of the Mityvac group . Of these , cephalhematomatas were noted in 2.2 % of the forceps group , 13.9 % of the Silastic group , and 16.2 % of the Mityvac group . All three instruments were considered effective outlet delivery Episiotomy is a widely-done intervention in childbirth , regardless of poor scientific evidence of its benefits . This r and omised controlled trial compares selective with routine use of a mediolateral episiotomy for women having first and second deliveries in 8 public maternity units in Argentina . 2606 women participated ; 1555 were nulliparous ( 778 in the selective group and 777 in the routine group ) and 1051 primiparous ( 520 in the selective group and 531 in the routine group ) . The two interventions compared were selective ( limited to specified maternal or fetal indications ) , and routine episiotomy ( following the hospital 's previous policy ) . Episiotomy was done in 30.1 % of deliveries in the selective , and 82.6 % in the routine group . The main outcome measure was severe perineal trauma . Severe perineal trauma was uncommon in both groups but was slightly less frequent in the selective group ( 1.2 % vs 1.5 % ) . Anterior perineal trauma was more common in the selective group but posterior perineal surgical repair , perineal pain , healing complications , and dehiscence were all less frequent in the selective group . Routine  episiotomy should be ab and oned and episiotomy rates above 30 % can not be justified One hundred and eighty one primigravid women delivering vaginally in July and August 1982 in the Rotunda Hospital , Dublin , were r and omly allocated to one of two groups . Patients in one group were to undergo episiotomy . Those in the other group were not to undergo episiotomy unless it was considered to be essential . The outcome was compared with that of the clinical practice over the previous six months at the hospital . Of the 92 patients allocated not to undergo episiotomy  , seven ( 8 % ) had one done for medical reasons compared with 507 ( 89 % ) in the previous six months . First degree tears occurred in 23 ( 25 % ) and second degree tears in 43 ( 47 % ) . Nineteen ( 21 % ) , however , retained an intact perineum compared with only 35 ( 6 % ) of the women who had delivered in the preceding six months . Assessment s of perineal pain , bruising , swelling , and healing and records of ingestion of analgesics were made for the first four days after delivery , and again at a check up six weeks after delivery , in patients who had had spontaneous vertex deliveries . Forty patients who underwent episiotomy and 37 who sustained a second degree tear formed two comparable groups . There was no difference in outcome between them . Data were also evaluated for 19 women who retained an intact perineum , 22 who sustained a first degree tear , and 11 who underwent episiotomy and epidural anaesthesia ; all 52 of these women had spontaneous vertex deliveries . Despite severe soft tissue injury in two patients those who fared best were those who retained an intact perineum . First degree tears were associated with symptoms similar to those associated with second degree tears . Those who fared worst were women who underwent episiotomy after epidural anaesthesia . The value of routine episiotomy in primigravid patients is question ed , but the final decision can be made only by the accoucheur at the time of imminent delivery The association between  episiotomy and severe ( third- and fourth-degree ) perineal lacerations was studied in 24,114 women . The overall rates of severe lacerations were 8.3 and 1.5 % for primiparous and multiparous women , respectively . Women who had  midline episiotomies  were nearly 50 times more likely and women who had mediolateral episiotomies were over eight times more likely to suffer a severe laceration than were women who did not undergo an episiotomy .  Severe lacerations were also more common after use of forceps , in occiput transverse and posterior presentations , among women with smaller pelvic outlet measurements or lower prepregnant weight , and with larger fetuses . The same factors that caused a woman to have an increased risk of laceration also made performance of an episiotomy more likely . After statistical adjustment for these risk factors , mediolateral episiotomy was associated with a 2.5-fold reduction in the risk of severe lacerations among primiparous women , and a statistically nonsignificant 2.4-fold increase among multiparous women , compared with no episiotomy . Midline episiotomy was associated with statistically significant 4.2- and 12.8-fold increases in the risk of lacerations among primiparous and multiparous women , respectively . We conclude that the risks and benefits of midline episiotomy should be evaluated in a r and omized clinical trial that compares policies of “ usual ” versus conservative use of episiotomy Abstract . The incidence and magnitude of retinal hemorrhages ( RH ) in a group of 23 preterm infants ( 29–35 weeks ) born spontaneously in vertex presentation have been compared with those of 23 others ( 28‐35 weeks ) born by gentle extraction with small forceps .  Distribution to the groups was r and om . The overall frequency of RH in both groups together was low , 6 % , with no statistically significant difference between the groups . No fundi with severe ( grade III ) hemorrhages were seen . Both the incidence and magnitude of RH were less in the preterm neonates when compared with previously reported figures in term infants born spontaneously or with forceps extraction . The study provides further evidence in support of the hypothesis that fetal head compression with venous congestion is the main cause of RH in the newborn Although the performance of perineal massage by a woman or her partner during the last weeks of pregnancy may help to prevent perineal trauma at delivery , the technique has never been evaluated rigorously . This study examined the feasibility of a r and omized , controlled trial , and more specifically assessed the participation rate , the acceptability of the intervention , and whether or not an attending physician could remain blind to participants ' groups . The pilot study was a single-blinded , r and omized , controlled trial . Nulliparous women , 32 to 34 weeks pregnant , were recruited from June 8 to July 31 , 1992 , at the offices of family physicians and obstetricians who practice at the Hôpital du Saint-Sacrement in Quebec City . Women assigned to the intervention group practice d daily 10-minute perineal massage and completed a diary , and those in the control group had st and ard care .  Women and attending physicians completed a question naire about the aspect of blindness . Among the 174 women who delivered during the study period , 104 ( 59.8 % ) were approached by a midwife and 46 ( 26.4 % ) were r and omized . Twenty ( 91.0 % ) of the 22 women in the massage group returned their perineal massage diaries . Based on the postpartum question naire , 20 women practice d the technique at least four times a week for three weeks or longer . No woman in the control group practice d massage . The attending physician was aware of the woman 's group in only three instances ( 6.7 % ) . Based on the results of this pilot study , a r and omized , controlled trial to evaluate the efficacy of perineal massage  in preventing perineal trauma at birth appears feasible Objective To compare the effect of two methods of perineal management used during spontaneous vaginal delivery on the prevalence of perineal pain reported at 10 days after birth OBJECTIVE Our purpose was to compare consequences for women of receiving versus not receiving median episiotomy early and 3 months post partum on the outcomes perineal pain , urinary and pelvic floor functioning by electromyography , and sexual functioning and to analyze the relationship between episiotomy and third- and fourth-degree tears . STUDY DESIGN A secondary cohort analysis was performed of participants within a r and omized clinical trial , analyzed by type of perineal trauma and pain , pelvic floor , and sexual consequences of such trauma , while controlling for trial arm . The study was conducted in three university or community hospitals ; 356 primiparous and 341 multiparous women were studied . R 
    Output:
    
Factors shown to increase perineal integrity include avoiding episiotomy , spontaneous or vacuum-assisted rather than forceps birth , and in nulliparas , perineal massage  during the weeks before childbirth .
Second-stage position has little effect .