3.1 Assessing the Start of Labour

Assessing the start of labour is one of the most important aspects of the management of labour. Signs of the start of labour are:

- painful contractions with a certain regularity
- effacement and/or dilatation of the cervix
- leakage of amniotic fluid
- bloody discharge

Rupture of the membranes is a clear sign that something irreversible has occurred. The other symptoms are less obvious: contractions may be felt long before labour actually starts, and cervical dilatation may be present weeks before the end of pregnancy, and may progress slowly to the time of labour (Crowther 1989). Notwithstanding these difficulties the birth attendant should be able to distinguish between false labour and the beginning of labour; usually a vaginal examination is necessary to detect alterations of the cervix. The establishment of the onset of labour is, inevitably, the basis for identifying prolonged labour requiring action. If the diagnosis “start of labour” is made erroneously, the result may be unnecessary interventions, such as amniotomy or oxytocin infusions. The diagnosis “prolonged latent phase” is usually better substituted by “false labour”, because actually labour has not yet started. Sometimes the distinction between “start of labour” and “false labour” can only be made after a short period of observation. In the WHO multicentre trial of the partograph (WHO 1994b) only 1.3% of the women were reported to have a prolonged latent phase. The cause of this small percentage can be twofold: at the introduction of the partograph in the hospitals a discussion of labour management took place which may have affected the way the latent phase is perceived. Also, active intervention in the latent phase is postponed by 8 hours in the partograph.

Spontaneous prelabour rupture of the membranes (PROM) at term provokes a lively discussion about the risk of vaginal examination (Schutte et al 1983), induction of labour and prophylactic antibiotics. In a recent randomized study on induction after 12 hours versus expectant management during 48 hours, in the induction group the need for pain medication was significantly greater and there were more interventions, while mild neonatal infection occurred in 1.6% in the induction group versus 3.2% in the group with expectant management. No routine prophylactic antibiotics were used and vaginal examination was only performed if labour had started (Ottervanger et al 1996). A conservative approach, which is supported by the existing evidence, would indicate a policy which requires observation without vaginal examination and without antibiotics, during the first 48 hours after PROM. If labour has not commenced spontaneously during that period (in about 20% of the women), consideration could be given to oxytocin induction. However, these results are obtained in populations of women from developed countries in good health, and in hospitals where it was possible to maintain high standards of hygiene at all times. In different populations a more active management may be advisable, with the use of antibiotics and earlier induction of labour. Given that in the developing world puerperal sepsis is often the third or fourth cause of maternal mortality all efforts should be made to prevent it, whatever its source.