The Management of
Normal Labour
|
The
objective of intrapartum care is to deliver a healthy baby to a
healthy mother. The preparation of the mother for the process of
parturition begins well before the onset of labour. This
includes
antenatal care and
antenatal classes to educate the parents-to-be. It is
important for the mother and her partner to understand what
actually happens during the various
stages
of labour.
The mother
should be advised to come into hospital, or to call the midwife
in the event of a home birth, when contractions are at regular
10?15 minute intervals, when there is a show or if and when the
membranes rupture. If the mother is in early labour, she should
be encouraged to take a shower and to empty her bowels and
bladder. Shaving of the pubic hair is no longer considered
necessary unless there is a likelihood of delivery by caesarean
section, in which case the abdomen should be shaved down to the
pubic hairline. It is common practice in the United Kingdom to
organize ?domino? (domiciliary
in
and
out)
deliveries, whereby the mother is discharged home 6 hours after
delivery, provided that the delivery is uncomplicated.
The Management of
Normal Labour
|
When a woman is admitted in labour, a history is taken and an
examination undertaken. The examination includes:
- temperature,
- pulse,
- respiration,
- blood pressure
- and state of hydration;
- the urine should be tested for glucose,
ketone bodies and protein
- examination of the abdomen: inspection,
palpation and auscultation to determine the fetal lie,
presentation and position, and the station of the presenting
part, as well as to determine the presence of a fetal
heartbeat
- vaginal examination in labour should be
performed only after cleansing of the vulva and introitus
and using an aseptic technique with sterile gloves and an
antiseptic cream. The following factors should be noted:
-
the consistency, effacement and
dilatation of the cervix
-
whether the membranes are intact or
ruptured and,
-
if ruptured, the colour of the
amniotic fluid
-
nature and presentation of the
presenting part
-
its relationship to the level of the
ischial spines
-
assessment of the bony pelvis and in
particular of the pelvic outlet.
The Management of
Normal Labour
|
The principles are:
- Observation and intervention if the
labour becomes abnormal
- Pain relief during labour and emotional
support for the mother
- Adequate hydration throughout labour.
The introduction of graphic records (partograms)
has proved to be a major advance in the management of labour
because it enables the early recognition of a labour that is
becoming dysfunctional. The value of this type of record
system is that it draws attention visually to any aberration
from normal progress in labour.
The fetal heart rate is charted as
beats/minute and decelerations of heart rate that occur
during contractions are recorded by an arrow down to the
lowest heart rate recorded on the partogram. These records
are an adjunct to the actual recording of fetal heart rate.
The time of rupture of the membranes and the
nature of the amniotic fluid (i.e. whether it is clear or
meconium-stained) are also recorded. Moulding of the fetal
head and the presence of caput are also noted they provide
an indicator of obstructed labour.
The Management of
Normal Labour
|
Progress in labour is measured by assessing
the rate of cervical dilatation and descent of the
presenting part. To assess the rate of progress, vaginal
examination should be performed on admission to hospital and
every 4 hours during the first stage of labour. Cervical
dilatation is recorded in centimetres along the scale of
0?10 of the cervicograph and a plot of the cervical
dilatation is recorded. The graph for progress in a normal
labour is recorded on the chart. Dilatation of the cervix
occurs in two well-defined phases. The
latent phase
starts at the onset of labour and ends at 3 cm
dilatation. This takes up some two thirds of the whole time
of labour. This is followed by the
active phase
that extends from the end of the latent phase
until the onset of the second stage when full cervical
dilatation has been reached.
If the dilatation of the cervix lags more
than two hours behind the expected rate of dilatation, the
labour is considered to be abnormal. The rate of dilatation
increases rapidly during the active phase of labour although
it slows again near the phase of full cervical dilatation.
The station of the head is also charted on the partogram
using the following definitions
- If the head is high, the level is
five-fifths above the pelvic brim
- If the head is just descending into the
pelvic brim, it is four-fifths above the brim
- If less than half the head is through
the brim, it is three fifths above the brim
- If more than half the head is through
the brim it is two-fifths above the brim
- If just the base of the skull is
palpable abdominally, it is one-fifth above the brim.
The station of the head is plotted on the
0?5 gradation of the partogram.
Descent is also recorded by assessing the
level of the presenting part above or below the level of the
ischial spines at vaginal examination. The nature and
frequency of the uterine contractions are recorded on the
chart by shading in the number of contractions per 10
minutes. Dotted squares indicate contractions of less than
20 seconds duration, crosshatched squares are contractions
between 20 and 40 seconds duration, while contractions
lasting longer than 40 seconds are shown by complete shading
of the squares.
The Management of
Normal Labour
|
If there is a likelihood that the mother will
need operative delivery under general anaesthesia, then it is
clearly important to avoid oral intake at any significant level
during the first stage of labour. Delayed gastric emptying may
result in vomiting and inhalation of vomitus if general
anaesthesia for operative delivery is needed. On the other hand,
most operative deliveries are now achieved under epidural
anaesthesia and therefore there is a case for giving some fluids
and light nutrition orally if labour is progressing normally and
a vaginal delivery can be anticipated. Intravenous fluid
replacement should be considered after 6 hours in labour if
delivery is not imminent. Dehydration is the major cause of
acidosis and ketosis.The classic signs of
dehydration in labour include tachycardia, mild pyrexia and loss
of tissue turgor. Remember that labour can be hard physical work
and that the environmental temperature of delivery rooms is
often raised to meet the needs of the baby rather than the
mother, leading to considerable insensible fluid loss.If
delivery is not imminent at the end of 6 hours, an intravenous
infusion should be commenced.
