Body Mass Index (BMI) and Childbirth.
Risks:
One of the aims of care during pregnancy is
to identify women who may need extra help
during the birth of their baby. One factor that
increases the risk of problems during birth is
being overweight. Women with a BMI of 45
and above will be referred to anaesthetist.
BMI is the relationship between your height
and weight. Women who are very overweight
have a BMI higher than 35. These women
are slightly more likely to need a caesarean
section to deliver their baby.
This means that women with a high BMI are
more likely to need an anaesthetic to allow a
caesarean section to be carried out. A high
BMI can also make some procedures more
difficult and time consuming, such as putting
a drip into a vein.
It is usually best for you to remain awake
during the birth of your baby by choosing
to have a spinal or epidural anaesthetic for
your caesarean section. A high BMI can
make general anaesthesia more difficult. For
example, when asleep it may be harder to put
a breathing tube into your throat.
Benefits:
Being awake for a caesarean section has
many advantages to you and your baby, both
during and after the operation. Pain relief
drugs given with a spinal or epidural are
more effective so that the amount of pain
felt afterwards is often much less than after
having a general anaesthetic.
However, it can be more difficult to find the
right place in the back to put a needle for
spinal or epidural injection, and therefore it
may take longer.
More information about having an epidural,
spinal or general anaesthetic, including the
risks, is given in our separate leaflets. Please
ask if you have not been given a copy of these.
During pregnancy an appointment to meet
an anaesthetist may be offered. This will
allow an anaesthetist to meet you and make
an assessment, and discuss pain relief and
anaesthetic choices for the labour and birth.
This is better done in relaxed surroundings
during pregnancy, rather than when in labour.
After meeting with the anaesthetist some
recommendations about pain relief in labour
may be made. For example, the anaesthetist
may suggest to you that, if labour is not
straightforward, having an epidural earlier
rather than later may be needed, because
putting an epidural in may take longer than
usual.
When arriving on delivery suite please tell
the midwives if an anaesthetic assessment
has been done. The anaesthetist on duty
will review the plan suggested by the
senior anaesthetist during pregnancy. If an
anaesthetist has not made a plan during
pregnancy, the duty anaesthetist will make one.
Omeprazole tablets will be given to you
during labour. This is a drug that helps to
reduce the acidity in the stomach, and will
make it safer if an urgent anaesthetic to
deliver the baby is needed.
Soon after the birth of your baby heparin
injections may be given for a few days and
compression stockings may need to be worn.
These help prevent blood clots in the legs
or lungs, which are more common during
and after pregnancy, and even more likely in
women with raised BMI. We will discuss this
after the baby is born.
To summarise:
• If your BMI is above 35, it is more likely
that some form of help with the birth of
the baby is needed, than someone with
a lower BMI.
• It is generally better to stay awake
during a caesarean section birth.
• General anaesthesia may be more
difficult and time consuming and the
anaesthetists need to plan for this.
• It can be more difficult to site epidurals
and spinals.
• When admitted to delivery suite to
have your baby, the anaesthetist on
duty may see you.
For further information about the details in
this leaflet please speak to your midwife.
Related documents:
Pain Relief in Labour (OAA publication)
Caesarean Section: your choice of
anaesthesia (OAA publication)
References
Saving Mothers Lives (CEMACH). London;
RCOG Press; 2007 [www.cemach.org.uk]
