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.