***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: BACKGROUND The Valsalva pushing technique is used routinely in the second stage of labor in many countries , and it is accepted as st and ard obstetric management in Turkey . The purpose of this study was to determine the effects of pushing techniques on mother and fetus in birth in this setting . METHODS This r and omized study was conducted between July 2003 and June 2004 in Bakirkoy Maternity and Children 's Teaching Hospital in Istanbul , Turkey . One hundred low-risk primiparas between 38 and 42 weeks ' gestation , who expected a spontaneous vaginal delivery , were r and omized to either a spontaneous pushing group or a Valsalva-type pushing group .  Spontaneous pushing women were informed during the first stage of labor about spontaneous pushing technique ( open glottis pushing while breathing out ) and were supported in pushing spontaneously in the second stage of labor . Similarly , Valsalva pushing women were informed during the first stage of labor about the Valsalva pushing technique ( closed glottis pushing while holding their breath ) and were supported in using Valsalva pushing in the second stage of labor . Perineal tears , postpartum hemorrhage , and hemoglobin levels were evaluated in mothers ; and umbilical artery pH , Po(2 ) ( mmHg ) , and Pco(2 ) ( mmHg ) levels and Apgar scores at 1 and 5 minutes were evaluated in newborns in both groups . RESULTS No significant differences were found between the two groups in their demographics , incidence of nonreassuring fetal surveillance patterns , or use of oxytocin . The second stage of labor and duration of the expulsion phase were significantly longer with Valsalva-type pushing . Differences in the incidence of episiotomy , perineal tears , or postpartum hemorrhage were not significant between the groups . The baby fared better with spontaneous pushing , with higher 1- and 5-minute Apgar scores , and higher umbilical cord pH and Po(2 ) levels . After the birth , women expressed greater satisfaction with spontaneous pushing . CONCLUSIONS Educating women about the spontaneous pushing technique in the first stage of labor and providing support for spontaneous pushing in the second stage result in a shorter second stage without interventions and in improved newborn outcomes . Women also stated that they pushed more effectively with the spontaneous pushing technique It has become custom and practice within the midwifery and obstetric professions in the English-speaking western world for women to be required to follow very specific instructions on how to push in the second stage of labour . There is very little literature on the behaviour of women using spontaneous pushing in the second stage of labour . In a pilot study of a r and omized controlled trial comparing  spontaneous ( n = 15 ) with directed ( n = 17 ) pushing  , the behaviour of the women was observed and recorded . The findings from the observational part of the study are reported in this paper . When pushing spontaneously women do not instinctively take a deep breath , they do not start expulsive effort with the commencement of the contraction , and they use both  open and closed glottis pushing .  In order to assist women in the second stage of labour , those caring for them should be aware of what is normal behaviour when women are using spontaneous expulsive effort It is routine to require women to ' take a deep breath in , hold it and push ' in the second stage of labour , but there is no scientific evidence to support this practice . In a r and omized controlled trial of  spontaneous ( n = 15 ) versus directed ( n = 17 )  pushing in the second stage , no adverse effects of spontaneous pushing on the woman or baby were found . There was a negative correlation between the length of the second stage and the venous cord blood pH at delivery in the directed pushing group , suggesting that a long second stage was disadvantageous to the fetus when the woman was using a directed pushing technique . No such association was found in the spontaneous pushing group , despite the fact that the women in this group had a significantly longer mean second stage Background . Pushing in the second stage of labor can be forced or follow the spontaneous urge to bear down . Recent studies have shown that spontaneous pushing results in a longer second stage , fewer CTG changes , higher arterial pH and less damage to the birth canal . Method . R and omized trial of spontaneous vs. forced pushing in 350 primiparous women . Results . There was no difference between the r and omized groups in duration of second stage of labor , umbilical arterial pH or damage to the birth canal . Of the women allotted to spontaneous pushing , 65.6 % used the closed glottis technique for more than half the expulsive phase . When dividing the women into two groups according to the actual pushing technique used most , open or  closed glottis  , it turned out that women who used the open glottis technique had a shorter second stage of labor and gave birth to infants with lower birth weight OBJECTIVE Episiotomy rates are declining in the United States . In setting s with very low rates , evidence remains sparse on how best to facilitate birth without lacerations . The purpose of this investigation was to identify maternal and clinical factors related to genital tract trauma in normal , spontaneous vaginal births . METHODS Data from a r and omized clinical trial of perineal management techniques were used to address the study objective . Healthy women had spontaneous births with certified nurse-midwives in a medical center setting . Proportions of maternal characteristics and intrapartum variables were compared in women who did and did not sustain sufficient trauma to warrant suturing , according to parity ( first vaginal births versus others ) . Logistic regression using a backward elimination strategy was used to identify predictors of obstetric trauma . RESULTS In women who had a first vaginal birth , risk factors for trauma were maternal education of high school or beyond , Valsalva pushing , and infant birthweight . Risk factors in women having a second or higher vaginal birth were prior sutured trauma and infant birthweight . For all mothers , delivery of the infant 's head between contractions was associated with reduced trauma to the genital tract . CONCLUSIONS Delivery technique that is unrushed and controlled may help reduce obstetric trauma in normal , spontaneous vaginal births OBJECTIVE It is believed that delivery is faster if women are instructed to voluntarily bear down in synchrony with their uterine contractions . Confronted by the large variance in the duration of the second stage of labor , many clinicians attribute a " fast " or a " short " expulsion time solely to the patient 's willingness to cooperate or to the strength of epidural anesthesia if it is a factor . Yet , knowledge of pushing performance and the factors affecting it remain limited . We investigated the maternal , fetal , and labor characteristics that influence the maternal " pushing performance " and sought to design a predictive index that prospect ively identified " high " versus " low " pushing performers . STUDY DESIGN  Intrauterine pressure ( IP ) was prospect ively measured during the second stage of labor in 52 women recruited at one North American hospital . Recordings were begun after documentation of full cervical dilatation and descent of the fetal head to + 2 station ( on a -3/+3 scale ) . Each woman acted as her own control , received epidural anesthesia , and was alert and responsive throughout the study . Pushing ( closed glottis technique ) was performed in a st and ardized fashion . Multivariate analysis with linear regression was applied to identify significant associations between maternal , fetal , or labor characteristics as the independent variables and the percent increase in IP consequent to active pushing as the dependent variable . RESULTS Women in labor increase their IP 62 % by actively pushing with a contraction during the second stage . A scattergram of the individual percent increase above the baseline IP integral revealed that for some women , pushing more readily increased their IP than it did for others ( range , 0 % to 192 % ) . The percent increase was best calculated by a linear combination of myometrial thickness , estimated fetal weight , the maternal body mass index , and the obstetric need for labor augmentation ( P = .007 , r = 0.52 , power = 0.975 ) . A 66 % change in IP provided the best separation between high and low pushing performance . Myometrial thickness provided the single strongest contribution to the regression equation 's predictive value ( P = .01 , r = -0.36 ) . A myometrial thickness of 6 mm had a specificity of 88 % ( but only 53 % sensitivity ) for the identification of women able to increase their IP by 66 % over baseline . CONCLUSIONS In women in labor who have received epidural anesthesia , the efficiency with which maternal expulsive efforts are converted into increased IP is directly related to the patient 's body mass index but inversely related to myometrial thickness , the sonographic estimate of fetal weight , and the need for labor augmentation OBJECTIVE The purpose of this study was to determine if refraining from coached pushing during the second stage of labor affects postpartum urogynecologic measures of pelvic floor structure and function . STUDY DESIGN Nulliparous women at term were r and omized to coached ( n = 67 ) vs uncoached ( n = 61 )  pushing . At 3 months ' postpartum women underwent urodynamic testing , pelvic organ prolapse examination ( POPQ ) , and pelvic floor neuromuscular assessment . RESULTS Urodynamic testing revealed decreased bladder capacity ( 427 mL vs 482 mL , P = .051 ) and decreased first urge to void ( 160 mL vs 202 mL , P = .025 ) in the coached group . Detrusor overactivity increased 2-fold in the coached group ( 16 % vs 8 % ) , although this difference was not statistically significant ( P = .17 ) . Urodynamic stress incontinence was diagnosed in the coached group in 11/67 ( 16 % ) vs 7/61 ( 12 % ) in the uncoached group ( P = .42 ) . CONCLUSION Coached pushing in the second stage of labor significantly affected urodynamic indices , and was associated with a trend towards increased detrusor overactivity 
    Output:
    
Neonatal outcomes did not differ significantly .
Urodynamic factors measured 3 months postpartum were negatively affected by Valsalva pushing .
The evidence from our review does not support the routine use of Valsalva pushing in the second stage of labour .
The duration of the second stage of labour is shorter with Valsalva pushing but the clinical significance of this finding is uncertain .