Randomised controlled trial of labouring in water compared with standard of augmentation for management of dystocia in first stage of labour
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《英国医生杂志》
1 Nightingale Building (67), University of Southampton, Southampton SO17 1BJ, 2 Medical Statistics Group, Health Care Research Unit (805), Southampton General Hospital, Southampton SO16 6YD, 3 Trust Management Office (Mail point 18), Southampton General Hospital, Southampton SO16 6YD
Correspondence to: E R Cluett ec1@soton.ac.uk
Abstract
Slower than expected progress in the first stage of labour (dystocia) occurs in 20% of nulliparous women in labour and accounts for 20% of caesarean sections and 40% of instrumental deliveries, and results in longer hospitalisation.1 For women at low risk of complications, it marks the transition from midwifery to obstetric management. Since proponents of active management first claimed the benefits of shorter labour and lower rates of caesarean section,2 3 debate has continued over conservative versus aggressive management and the medicalisation of birth. Management strategies for dystocia vary from immediate augmentation4 5 to delayed intervention up to four hours after diagnosis.6-8 Comparison between strategies is difficult as specific features often differ; for example, one-to-one care is recognised to have beneficial effect on labour outcomes.9
Our current trial was based on two precepts. Firstly, that incomplete understanding of labour may lead to unnecessarily early intervention. Secondly, that anxiety and pain may trigger a stress response,10 leading to reduced uterine activity and dystocia.11 Labouring in water may ameliorate this stress response by aiding relaxation and pain relief. Few trials have evaluated labouring in water, perhaps because of the difficulty in randomising women who may have strong preferences.12 A Cochrane review concluded that, for women at low risk of complications, there was no clear evidence of advantage or disadvantage in using a pool in labour but further research was needed.13 Two national surveys concluded that labour and birth in water had no effect on perinatal mortality.14 15
In preparation for the trial reported here, we conducted a feasibility study comparing labour in water with augmentation and conservative management for women with dystocia,16 but conservative management was considered unacceptable by women and clinicians. Our current trial therefore compares labour in water with augmentation in nulliparous women with dystocia.
Participants and methods
Recruitment
Of 3825 nulliparous women who delivered in the unit during the two years of recruitment, 741 were defined as being at low risk of complications at the time of the diagnosis of dystocia (see figure). Consent was sought from 176 eligible women, of whom 99 (56%) agreed to participate, and were randomised. The two groups of women showed no important differences in baseline characteristics (table 1). There was good adherence to the trial protocol, with 48 of the 49 women allocated to labour in water using the pool, and 48 of the 50 women allocated to standard care receiving augmentation. The woman who declined to enter the water requested an amniotomy. Two women in the augmentation group progressed before augmentation could be started.
Flow of participants through trial
Table 1 Baseline characteristics of nulliparous women with dystocia allocated to labour in a birth pool or standard augmentation (amniotomy and intravenous oxytocin). Values are numbers (percentages) of women unless otherwise indicated
Primary outcomes
Twenty three women (47%) allocated to labour in water received epidural analgesia after randomisation compared with 33 (66%) in the augmentation group (relative risk 0.71 (95% confidence interval 0.49 to 1.01), number needed to treat 5) (table 2). The numbers of operative deliveries (caesarean sections and ventouse and forceps deliveries) were similar in both arms of the trial, with 24 (49%) women allocated to labour in water receiving an operative delivery compared with 25 (50%) women allocated to augmentation (relative risk 0.98 (0.65 to 1.47), number needed to treat 98).
Table 2 Epidural analgesia, mode of delivery, and secondary outcomes among nulliparous women with dystocia allocated to labour in a birth pool or standard augmentation (amniotomy and intravenous oxytocin). Values are numbers (percentages) of women unless otherwise indicated
Secondary outcomes
Twenty five of the 27 women in the water labour arm who had made slow progress at the assessment four hours after recruitment received augmentation. A further three women progressed slowly subsequently and also received augmentation. Seven women who progressed satisfactorily received an amniotomy for other indications. The number of women who received augmentation (amniotomy or oxytocin) in the water labour arm was significantly lower than that in the standard care arm (35 (71%) v 48 (96%), relative risk 0.74 (0.59 to 0.88), number needed to treat 4) (table 2).
The mean duration of the first stage of labour was similar in the two groups, 10.47 hours in the water labour group and 10.26 hours in the augmentation group (table 3). Women allocated to labour in water reported significantly lower mean pain scores at 30 minutes after start of the allocated management (49 mm v 64 mm) and a reduction in mean pain (-26 mm) compared with an increase for women receiving augmentation (12 mm). Women allocated to labour in water were more likely to report satisfaction with freedom of movement (91% v 63%) and with experience of privacy (96% v 81%), but there was no difference between groups in overall satisfaction (table 3).
Table 3 Labour length and retrospectively reported pain and satisfaction among nulliparous women with dystocia allocated to labour in a birth pool or standard augmentation (amniotomy and intravenous oxytocin). Values are numbers (percentages) of women unless otherwise indicated
Maternal and neonatal wellbeing
Maternal and neonatal infection rates were similar in the two groups (table 4), as was neonatal condition at birth indicated by Apgar score and umbilical cord pH. Six neonates born to women in the water labour group were admitted to the neonatal unit compared with none in the augmentation group (P = 0.013). The reasons for admission were: cardiac defects (1), hypothermia (2), fever (1), suspected infection on day 2 (1), and poor feeding on day 3 (1). There was a mean delay of 6 hours (range 2-10 hours) between women leaving the pool and birth. With the exception of the infant with cardiac defects, all these neonates, who had required an operative delivery, were reunited with their mothers within 48 hours and experienced no subsequent problems.
Table 4 Maternal and neonatal morbidity, including infection, for nulliparous women with dystocia allocated to labour in a birth pool or standard augmentation (amniotomy and intravenous oxytocin). Values are numbers (percentages) unless otherwise indicated
Discussion
Department of Health. NHS maternity statistics, England 1989/90 to 1994/95. Statistical Bulletin No 28. London: Stationery Office, 1997: 1-16.
Johanson R, Newburn M, MacFarlane A. Has the medicalisation of childbirth gone too far? BMJ 2002;324: 892-5.
Impey L, Boylan P. Active management of labour revisited. Br J Obstet Gynaecol 1999;106: 183-7.
Cammu H, Van Eeckhout E. A randomised controlled trial of early versus delayed use of amniotomy and oxytocin infusion in nulliparous labour. Br J Obstet Gynaecol 1996;103: 313-8.
Sadler LC, Davison T, McCowen LME. A randomised controlled trial and meta analysis of active management of labour. Br J Obstet Gynaecol 2000;107: 909-15.
World Health Organisation maternal health and safe motherhood programme. World Health Organisation partograph in the management of labour. Lancet 1994;343: 1399-404.
Blanch G, Lavender T, Walkinshaw S, Alfirevic A. Dysfunctional labour: a randomised trial. Br J Obstet Gynaecol 1998;105: 117-20.
Lavender T, Walkinson S, Walton I. A prospective study of women's views of factors contributing to a positive birth experience Midwifery 1999;15: 40-6.
Hodnett ED. Support from caregivers during childbirth. (Cochrane review) In: Cochrane Library. Issue 1. Oxford: Update Software, 2003.
Brownridge P. The nature and consequence of childbirth pain. Eur J Obstet Gynecol Reprod Biol 1995;32(suppl): S9-15.
De Punzio C, Neri E, Metelli P, Bianchi MS, Venticinqui M, Ferdeghini M, et al. The relationship between maternal relaxation and plasma beta endorphin levels during parturition. J Psychosom Obstet Gynaecol 1994;15: 205-10.
Garland D, Jones K. Waterbirth, first stage immersion or non immersion? Br J Midwifery 1994;2(3): 113-20.
Nikodem VC. Immersion in water during pregnancy, labour and birth. In: Cochrane Library. Issue 1. Oxford: Update Software, 2003.
Gilbert RE, Tookey PA. Perinatal mortality and morbidity among babies delivered in water; surveillance study and postal survey. BMJ 1999;319: 483-7.
Alderdice F, Renfrew M, Marchant S, Ashurst H, Hughes P, Berridge G, et al. Labour and birth in water in England and Wales. BMJ 1995;310: 837.
Cluett ER, Pickering RM, Brooking JI. An investigation into the feasibility of comparing three management options (augmentation, conservative and water) for nulliparae with dystocia in the first stage of labour. Midwifery 2001;17: 35-43.
Altman DG. Confidence intervals for the number needed to treat. BMJ 1998;317: 1309-12.
Green JM, Coupland VA, Kitzinger JV. Great expectations. A prospective study of women's expectations and experiences of childbirth. 2nd ed. Cheshire: Books for Midwives, 1998.
Schorn MN, McAllister JL, Blanco JD. Water immersion and the effect on labor. J Nurse Midwifery 1993;38: 336-42.
Rush J, Burlock S, Lambert K, Loasley-Milman M, Hutchinson B, Enkin M. The effects of whirlpool baths in labour: a randomised controlled trial. Birth 1996;23: 136-43.
Cammu H, Clasen K, Wettere L, Derde M-P. To bathe or not to bathe during the first stage of labor. Acta Obstet Gynecol Scand 1994;73: 468-72.
Eckert K, Turnbull D, MacLennan A. Immersion in water in the first stage of labour: a randomised controlled trial. Birth 2001;28: 84-93.
Aird IA, Luckas MJM, Buckett WM, Bousfielf P. Effects intrapartum hydrotherapy on labour parameters. Aust N Z J Obstet Gynaecol 1997;37: 137-42.
Otigbah CM, Dhanjal MK, Harmsworth G. A retrospective comparison of water births and conventional vaginal deliveries. Eur J Obstet Gynecol Reprod Biol 2000;91: 15-20.
Ohlsson G, Buchhave P, Leandersson U, Nordstrom L, Rydhstrom H, Sjolin I. Warm tub bathing during labor; maternal and neonatal effects. Acta Obstet Gynecol Scand 2001;80: 311-4.(Elizabeth R Cluett, lectu)
Correspondence to: E R Cluett ec1@soton.ac.uk
Abstract
Slower than expected progress in the first stage of labour (dystocia) occurs in 20% of nulliparous women in labour and accounts for 20% of caesarean sections and 40% of instrumental deliveries, and results in longer hospitalisation.1 For women at low risk of complications, it marks the transition from midwifery to obstetric management. Since proponents of active management first claimed the benefits of shorter labour and lower rates of caesarean section,2 3 debate has continued over conservative versus aggressive management and the medicalisation of birth. Management strategies for dystocia vary from immediate augmentation4 5 to delayed intervention up to four hours after diagnosis.6-8 Comparison between strategies is difficult as specific features often differ; for example, one-to-one care is recognised to have beneficial effect on labour outcomes.9
Our current trial was based on two precepts. Firstly, that incomplete understanding of labour may lead to unnecessarily early intervention. Secondly, that anxiety and pain may trigger a stress response,10 leading to reduced uterine activity and dystocia.11 Labouring in water may ameliorate this stress response by aiding relaxation and pain relief. Few trials have evaluated labouring in water, perhaps because of the difficulty in randomising women who may have strong preferences.12 A Cochrane review concluded that, for women at low risk of complications, there was no clear evidence of advantage or disadvantage in using a pool in labour but further research was needed.13 Two national surveys concluded that labour and birth in water had no effect on perinatal mortality.14 15
In preparation for the trial reported here, we conducted a feasibility study comparing labour in water with augmentation and conservative management for women with dystocia,16 but conservative management was considered unacceptable by women and clinicians. Our current trial therefore compares labour in water with augmentation in nulliparous women with dystocia.
Participants and methods
Recruitment
Of 3825 nulliparous women who delivered in the unit during the two years of recruitment, 741 were defined as being at low risk of complications at the time of the diagnosis of dystocia (see figure). Consent was sought from 176 eligible women, of whom 99 (56%) agreed to participate, and were randomised. The two groups of women showed no important differences in baseline characteristics (table 1). There was good adherence to the trial protocol, with 48 of the 49 women allocated to labour in water using the pool, and 48 of the 50 women allocated to standard care receiving augmentation. The woman who declined to enter the water requested an amniotomy. Two women in the augmentation group progressed before augmentation could be started.
Flow of participants through trial
Table 1 Baseline characteristics of nulliparous women with dystocia allocated to labour in a birth pool or standard augmentation (amniotomy and intravenous oxytocin). Values are numbers (percentages) of women unless otherwise indicated
Primary outcomes
Twenty three women (47%) allocated to labour in water received epidural analgesia after randomisation compared with 33 (66%) in the augmentation group (relative risk 0.71 (95% confidence interval 0.49 to 1.01), number needed to treat 5) (table 2). The numbers of operative deliveries (caesarean sections and ventouse and forceps deliveries) were similar in both arms of the trial, with 24 (49%) women allocated to labour in water receiving an operative delivery compared with 25 (50%) women allocated to augmentation (relative risk 0.98 (0.65 to 1.47), number needed to treat 98).
Table 2 Epidural analgesia, mode of delivery, and secondary outcomes among nulliparous women with dystocia allocated to labour in a birth pool or standard augmentation (amniotomy and intravenous oxytocin). Values are numbers (percentages) of women unless otherwise indicated
Secondary outcomes
Twenty five of the 27 women in the water labour arm who had made slow progress at the assessment four hours after recruitment received augmentation. A further three women progressed slowly subsequently and also received augmentation. Seven women who progressed satisfactorily received an amniotomy for other indications. The number of women who received augmentation (amniotomy or oxytocin) in the water labour arm was significantly lower than that in the standard care arm (35 (71%) v 48 (96%), relative risk 0.74 (0.59 to 0.88), number needed to treat 4) (table 2).
The mean duration of the first stage of labour was similar in the two groups, 10.47 hours in the water labour group and 10.26 hours in the augmentation group (table 3). Women allocated to labour in water reported significantly lower mean pain scores at 30 minutes after start of the allocated management (49 mm v 64 mm) and a reduction in mean pain (-26 mm) compared with an increase for women receiving augmentation (12 mm). Women allocated to labour in water were more likely to report satisfaction with freedom of movement (91% v 63%) and with experience of privacy (96% v 81%), but there was no difference between groups in overall satisfaction (table 3).
Table 3 Labour length and retrospectively reported pain and satisfaction among nulliparous women with dystocia allocated to labour in a birth pool or standard augmentation (amniotomy and intravenous oxytocin). Values are numbers (percentages) of women unless otherwise indicated
Maternal and neonatal wellbeing
Maternal and neonatal infection rates were similar in the two groups (table 4), as was neonatal condition at birth indicated by Apgar score and umbilical cord pH. Six neonates born to women in the water labour group were admitted to the neonatal unit compared with none in the augmentation group (P = 0.013). The reasons for admission were: cardiac defects (1), hypothermia (2), fever (1), suspected infection on day 2 (1), and poor feeding on day 3 (1). There was a mean delay of 6 hours (range 2-10 hours) between women leaving the pool and birth. With the exception of the infant with cardiac defects, all these neonates, who had required an operative delivery, were reunited with their mothers within 48 hours and experienced no subsequent problems.
Table 4 Maternal and neonatal morbidity, including infection, for nulliparous women with dystocia allocated to labour in a birth pool or standard augmentation (amniotomy and intravenous oxytocin). Values are numbers (percentages) unless otherwise indicated
Discussion
Department of Health. NHS maternity statistics, England 1989/90 to 1994/95. Statistical Bulletin No 28. London: Stationery Office, 1997: 1-16.
Johanson R, Newburn M, MacFarlane A. Has the medicalisation of childbirth gone too far? BMJ 2002;324: 892-5.
Impey L, Boylan P. Active management of labour revisited. Br J Obstet Gynaecol 1999;106: 183-7.
Cammu H, Van Eeckhout E. A randomised controlled trial of early versus delayed use of amniotomy and oxytocin infusion in nulliparous labour. Br J Obstet Gynaecol 1996;103: 313-8.
Sadler LC, Davison T, McCowen LME. A randomised controlled trial and meta analysis of active management of labour. Br J Obstet Gynaecol 2000;107: 909-15.
World Health Organisation maternal health and safe motherhood programme. World Health Organisation partograph in the management of labour. Lancet 1994;343: 1399-404.
Blanch G, Lavender T, Walkinshaw S, Alfirevic A. Dysfunctional labour: a randomised trial. Br J Obstet Gynaecol 1998;105: 117-20.
Lavender T, Walkinson S, Walton I. A prospective study of women's views of factors contributing to a positive birth experience Midwifery 1999;15: 40-6.
Hodnett ED. Support from caregivers during childbirth. (Cochrane review) In: Cochrane Library. Issue 1. Oxford: Update Software, 2003.
Brownridge P. The nature and consequence of childbirth pain. Eur J Obstet Gynecol Reprod Biol 1995;32(suppl): S9-15.
De Punzio C, Neri E, Metelli P, Bianchi MS, Venticinqui M, Ferdeghini M, et al. The relationship between maternal relaxation and plasma beta endorphin levels during parturition. J Psychosom Obstet Gynaecol 1994;15: 205-10.
Garland D, Jones K. Waterbirth, first stage immersion or non immersion? Br J Midwifery 1994;2(3): 113-20.
Nikodem VC. Immersion in water during pregnancy, labour and birth. In: Cochrane Library. Issue 1. Oxford: Update Software, 2003.
Gilbert RE, Tookey PA. Perinatal mortality and morbidity among babies delivered in water; surveillance study and postal survey. BMJ 1999;319: 483-7.
Alderdice F, Renfrew M, Marchant S, Ashurst H, Hughes P, Berridge G, et al. Labour and birth in water in England and Wales. BMJ 1995;310: 837.
Cluett ER, Pickering RM, Brooking JI. An investigation into the feasibility of comparing three management options (augmentation, conservative and water) for nulliparae with dystocia in the first stage of labour. Midwifery 2001;17: 35-43.
Altman DG. Confidence intervals for the number needed to treat. BMJ 1998;317: 1309-12.
Green JM, Coupland VA, Kitzinger JV. Great expectations. A prospective study of women's expectations and experiences of childbirth. 2nd ed. Cheshire: Books for Midwives, 1998.
Schorn MN, McAllister JL, Blanco JD. Water immersion and the effect on labor. J Nurse Midwifery 1993;38: 336-42.
Rush J, Burlock S, Lambert K, Loasley-Milman M, Hutchinson B, Enkin M. The effects of whirlpool baths in labour: a randomised controlled trial. Birth 1996;23: 136-43.
Cammu H, Clasen K, Wettere L, Derde M-P. To bathe or not to bathe during the first stage of labor. Acta Obstet Gynecol Scand 1994;73: 468-72.
Eckert K, Turnbull D, MacLennan A. Immersion in water in the first stage of labour: a randomised controlled trial. Birth 2001;28: 84-93.
Aird IA, Luckas MJM, Buckett WM, Bousfielf P. Effects intrapartum hydrotherapy on labour parameters. Aust N Z J Obstet Gynaecol 1997;37: 137-42.
Otigbah CM, Dhanjal MK, Harmsworth G. A retrospective comparison of water births and conventional vaginal deliveries. Eur J Obstet Gynecol Reprod Biol 2000;91: 15-20.
Ohlsson G, Buchhave P, Leandersson U, Nordstrom L, Rydhstrom H, Sjolin I. Warm tub bathing during labor; maternal and neonatal effects. Acta Obstet Gynecol Scand 2001;80: 311-4.(Elizabeth R Cluett, lectu)