This is a very serious complication that is fortunately rare.
It is serious for the mother because the blood loss that ensues can be life-threatening.
For the fetus, this occurrence causes very severe acute fetal distress, where the
only hope of saving the baby is delivery within minutes of the rupture occurring.
Delivery in this situation is almost always abdominal (caesarean).
The uterus could rupture as a result of over-stimulation of an already weakened womb.
Mothers who have had many babies are at particular risk of this complication. Over-stimulation
may be spontaneous, probably combined with another factor such as a big baby. It
could also result from administration of an oxytocin infusion.
Rupture of the uterus may occur in the presence of normal contractions in cases where
there is an abnormally weak scar on the uterus following previous surgery.
When a uterus ruptures, the baby is likely to be lost. Even the few that survive
are at high risk of ending up with brain damage, because of prolonged oxygen starvation
lasting several minutes.
Lying on one's back is regarded as unwise in labour. Why is that?
The heavy uterus will be lying on top of the major blood vessels in the mother's
abdomen. This may be severe enough to reduce the amount of blood flowing through
these vessels. This will result in inadequate oxygen delivery to the uterus itself
and hence to the baby. It could lead to fetal distress. Propped-up, sitting up and
left side positions are considered more ideal, as far the baby's welfare is concerned.
How is fetal distress recognized?
If fetal distress occurs before the onset of labour, the mother may get a warning
in the form of suddenly reduced or complete disappearance of fetal movements. In
cord accidents, the fetus may react by suddenly increasing movements. The mother
may therefore experience uncharacteristic vigorous fetal activity. In many cases,
pre-labour fetal distress may go unsuspected and unrecognised, sometimes with catastrophic
results. Pre-labour fetal distress is not common.
What about fetal distress in labour?
This is where the essence of fetal surveillance during labour is demonstrated. Many
cases of fetal distress will have no warning whatsoever and it is only the fetal
monitoring which will give a clue that something may not be right.
Electronic fetal monitoring in the form of cardiotocography (CTG) is now the standard
form of fetal surveillance in labour in most countries.
How does CTG monitoring help in detecting fetal distress?
CTGs monitor the unborn baby's heartbeat and how this is behaving. The contractions
are also monitored and their frequency, timing and duration are recorded. Standard
CTGs do not measure the strength of contractions.
By looking at the pattern of the heartbeat both in isolation and in relation to the
uterine contractions, it is possible for a midwife or doctor to identify signs of
Does this mean CTG monitoring needs to be continued throughout the entire duration
Not at all. Different units operate different policies on this matter. However, the
scientific evidence available indicates that properly timed intermittent monitoring
is just as good as continuous monitoring in its ability to detect fetal distress.
This applies to low-risk pregnancies, which are the majority.
For high-risk pregnancies, such as in cases of intrauterine fetal growth restriction
(IUGR) or previous unexplained stillbirth, all agree that continuous monitoring is
the appropriate policy. This is because the behaviour of such babies is less predictable
and this measure will be reassuring to the parents, who will be inevitably anxious.