Labour Augmentation by Means of Oxytocin - Obstetric Outcome and Women's Experiences
Condition: Slow Labour Progress
Study type: Interventional

Summary: 
      Slow labour progress is common in nulliparous women and is associated with childbirth
      complications and negative birth experiences. Oxytocin augmentation is widely used to treat
      slow labour despite associated risks for the fetus. An ongoing debate concerns whether
      oxytocin should be administered directly or postponed after arrested labour. The overall aim
      is to study labour progress in healthy nulliparous women and to compare childbirth outcomes
      and experiences in women randomised to expectant versus early oxytocin augmentation for slow
      labour progress.

      The hypothesis is that it is to early to start oxytocin treatment when labour progress has
      been slow for 2 to 3 hours in healthy women having their first baby and therefore beneficial
      for childbirth outcomes to postpone oxytocin for another 3 hours. In this randomised
      controlled trial nulliparous women with a normal pregnancy, spontaneous onset of active labor
      at term, and a cervical dilatation of 4 - 9 centimetres on admission to the delivery ward
      were included (n=2,072). All women whose labour did not progress after amniotomy (n=630) were
      randomly allocated either to labour augmentation by oxytocin infusion (Early oxytocin, n=314)
      or to postponement of oxytocin augmentation for another three hours (Expectant, n=316). One
      month postpartum the women received a postal questionnaire concerning their experiences of
      labour and birth. All participating women gave their informed consent. Maternal and neonatal
      outcomes like mode of delivery, postpartum haemorrhage, perinatal lacerations, low Apgar
      score, need of neonatal intensive care and maternal experiences of childbirth were compared
      between the randomised groups.
    

Detailed description: 
      In contemporary handling of labouring women in the western world, it has become extremely
      common to intervene through "active" or disciplined" management (Enkin et al., Widela et al.,
      Gerdhardstein et al., Frigoletto et al). It is a widespread routine - and potential side
      effects will therefore have a great impact. The use of the hormone oxytocin to enhance and
      speed up labour is the most common method, but the sparse scientific data regarding its
      effect are inconsistent and mostly demonstrate uncertain and sometime side effects (Thornton
      & Lilford, Frazer 1994, 1998, Cammu & Van Eeckhout).

      The effects, when evaluated, are short-term effects of maternal (obstetric) and fetal
      outcomes. The studies performed have mostly aimed to investigate whether the active
      management can reduce the rate of caesarean sections. However, in a meta-analysis of four
      randomised studies of the effects of oxytocin as intervention in spontaneous labour (Frazer),
      no significant reduction in the incidence of caesarean section, instrumental deliveries, and
      use of analgetics or hyper stimulation of labour was found. The only statically significant
      differences were in side effects: an increased incidence of discomfort and of pain in the
      group given oxytocin. In this meta-analysis, no significant differences in fetal conditions
      between the groups were found.

      Only one of the studies found sought the women's view on the augmentation procedures (Enkin).
      Over half of the women who were interviewed, said that the oxytocin treatment was unpleasant
      and indicate that they would like to try without the drug when giving birth the next time.
      Over 80% felt that it had increased the amount of pain that they had experienced.

      In spite of poor evidence of benefits, around half of birth giving women in Sweden receive
      oxytocin during labour and in some other countries, far more than that (Waldenström,
      O'Driscoll, Enkin). It has become the standard care of treating labours with slow progress.
      According to an investigation by the Swedish National Board of Health and Welfare
      (Socialstyrelsen 1996), the indications for oxytocin use and the amounts administered are not
      systematically recorded, and the assessments of its effects are even less well recorded. This
      makes evaluation by using existing documents very unreliable, and randomised controlled
      studies.

      Aims of the study

      The aims of the study are:

        -  To study the effects of oxytocin treatment vs no or delayed oxytocin treatment on the
           obstetrical and fetal outcome of spontaneous, but prolonged labour. Primary outcome is
           rate of spontaneous vaginal deliveries. Secondary outcome are length of labour,
           postpartum haemorrhage, sphincter lacerations, Apgar score, perceived pain and sense of
           safety.

        -  To study labour experiences in women exposed to oxytocin treatment vs women without
           oxytocin treatment.

      Methods

      The planned study design is a randomised controlled study with healthy women with normal
      pregnancies and spontaneous labour, where labour progression is deemed to be prolonged.

      Inclusion criteria

      Healthy women with full-term, normal pregnancies, spontaneous onset of active labour (effaced
      cervix and minimum 4 cm dilated) and about to give birth to their first child.

      Exclusion criteria

      Women with multiple pregnancies, complicated pregnancies, maternal disease during
      pregnancies, ruptured membranes for more than 2 hours before onset of labour contractions,
      and fetus in breech presentation.

      Sample size calculation

      A sample size of 247 in each group is needed to show a difference in spontaneous vaginal
      deliveries from 81,2% to 90% with a 2-sided test, alpha=0,05 and 80% power.

      Procedure

      Women fulfilling the criteria as described above are regarded as potential study subjects.
      Information about the study is distributed during the last trimester at the antenatal clinic.
      On arrival at the delivery ward, all women fulfilling these criteria are again informed about
      the study and asked for consent to participate. The progression of labour is thoroughly
      followed and documented for women who have agreed to participate. If the labour is prolonged
      during the active phase and is classified as inertia, i.e. with no further opening of the
      cervix for 2 hours or less than 1 cm in 3 hours, the subject are randomly allocated to either
      labour augmentation by means of oxytocin infusion within twenty minutes (standard care) or to
      expectancy and observation another 3 hours (experimental group) If the subjects in the
      experimental group after the 3 hours still do not progress in their labour, a reassessment
      regarding the need for labour augmentation is done. Women fulfilling inclusion criteria, and
      who have agreed to participate, but whose labours proceed normally, are followed according
      the same protocol, hence serving as external controls.

      Assessment and follow-up

      The handling of the participants will be done according to a standard protocol holding
      continuous documentation of the progression of labour, of the amount of oxytocin
      administered, of the analgesia used and of the obstetric outcome (caesarean section,
      instrumental vaginal delivery, length of labour, Apgar score etc). At the inclusion in the
      study, the women assess their expectancies, their perceived pain and sense of safety, using a
      visual analogue scale. Pain and sense of safety is then assessed at several occasions during
      and after delivery.

      In order to study the women's retrospective perceptions of their labour, they receive a
      questionnaire regarding their perceived experience one month post partum. This instrument
      focus on perceived pain, perceived safety, perceived participation in decision-making, sense
      of control and patient satisfaction. This questionnaire also contains questions regarding
      breast-feeding and a separate part is to be answered by the father. The latter part holding
      questions about the fathers' levels of preparation for the delivery, and his expectations and
      experiences as a supportive person in the labour room. A subgroup of the subjects (24 + 24) -
      oxytocin exposed and unexposed women - will be interviewed at one and four months after
      birth, using a qualitative interview method.

      Assessment of the baby is done at birth through Apgar scoring, fetal pH and base excess from
      the umbilical cord blood. In addition to this, a subgroup of the neonates will get their
      motor activity, heart frequency and respiration activity continuously registered during the
      first night after birth. This is done with the help of a so-called "sleep-box"

      Safety

      Three hours after the inclusion in the study, a reassessment of the progress of the labour is
      performed to evaluate whether the progression is satisfactory, or if oxytocin for those
      assigned to the experimental group is assessed to be required (procedures).

      Reassessments are then done regularly with 2-3 hours interval.

      Ethics

      Making a randomised, clinical study with care/treatment group and non-care/non-treatment
      group, always raises the question whether it is good ethics or not to abstain from the
      presently applied care programme. In this case, scientific data regarding the beneficial
      outcomes are ambiguous and inconsistent, and it is thus not obvious which of the procedures
      offered is "best" for the woman and the child. With this background, performing the study
      including well informed subjects and aiming at evaluating effects of standard procedures,
      must be considered ethically acceptable.

      Importance of the study

      There are few controlled studies on the effects of the standard procedure of treating slow
      labour progression with oxytocin and these show conflicting results. Considering this
      widespread treatment involving large population of women and newborns, it is of great
      importance to evaluate potential benefits and side effects in controlled studies. Knowledge
      about this is especially important in the reorganisation and rationing of resources within
      obstetric services. In the attempts to shorten women's hospital stays, the shortening of
      duration of labour has sometimes been considered a means to make obstetric care more
      cost-efficient and this fact makes independent evaluation of the care even more important.

      Furthermore, patients have the right to get evidence based care and treatment. This study
      will hopefully contribute to a better evidence based handling of women in labour who are
      subjected to secondary inertia, and in addition it will give us more information about
      fathers' experiences, which will help us enhance the care of the next-to-kin of the labouring
      woman.

      References

      Cammu H, Eeckhout E. A randomised controlled study of early versus delayed use of amniotomy
      and oxytocin infusion in nulliparous labour. Br J Obstet Gynaecol 1996 Apr;103(4):313-8

      Elwood JM. Causal relationships in medicine. Oxford medical publications, Oxford University
      Press, 1992

      Enkin M, Keirse MJNC, Chalmers I. A guide to effective care in pregnancy and childbirth. Pp
      205-210, 1994, Oxford University Press Fleiss. Statistical methods for rates and proportions.
      2nd ED. Wiley, 1981.

      Frazer W, Vendittelli F, Krauss I, Breart G. Early augmentation of labour with amniotomy and
      oxytocin in nulliparous women: a meta-analysis. Br J Obstet Gynaecol 1998Feb;105(2):189-94.

      Frazer WD. Early oxytocin to shorten spontaneous labour. In:Keirse MJNC, Renfrew MJ, et al.,
      eds. Pregnancy and childbirth module, Cochrane Databas of Systematic Reviews. (Cochrane
      updates on disk. The Cochrane Collaboration; Issue 2, Oxford:

      Update software, 1995).

      Frigoletto FD, Lièberman E, Lang JM, et al. A Clinical trial of active management of labour.
      NEJM, 1995;333(12):745-50.

      Gerhardstein LP, Allswede MT, Sloan CT, et al. Reduction in the rate of cesarean birth with
      active management of labour and intermediate-dose oxytocin. J Reprod Med 1995;40(1):4-8

      Linde A. Active management of labour - positiva och negativa effekter på den normala
      förlossningen. 10-poängsuppsats, Barnmorskeutbildningen, Vårdhögskolan i Göteborg, Jan 1997

      O'Driscoll K, Foley M, Macdonald D. Active management of labour as an alternativ to cesarean
      section of dystocia. Obstet Gynaecol 1984;63:485-90

      SoS-rapport 1996:24 Hur säker är förlossningsvården?

      Thornton JG. Active management of labour: current knowledge and research issues. BMJ
      1994;309:366-69.

      Videla FK, SatinAJ, Barth WH, et al. Trial of labour: A disciplined approach to labour
      management resulting in a high rate of vaginal delivery. AM J Perinatol 1995 May;12(3):181-4

      Waldenström U, Bergman V, Vasell G. The complexity of labour pain: experiences of 278 women.
      J Psychosom Obstet Gynaecol 1996 Dec;17(4):215-28.
    

Intervention name(s): Expectancy of standard oxytocin treatment
Intervention type(s): Other
Intervention MeSH terms: Oxytocin
Allocation: Randomized
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: randomised controlled trial; nulliparous women; slow labour progress; prolonged labour; oxytocin augmentation; operative delivery; childbirth experience