Expectant mothers
During pregnancy, as many as 30% of women experience low back
pain or sciatica (referred
or irradiated
pain in the leg). They also frequently experience pain after giving
birth.
During pregnancy, pain occurs in the vast majority of cases
as a result of spasm of the back muscles, which can cause
pain by way of several mechanisms. Once the pain occurs, regardless
of the factors that started it, there is a neurological mechanism
that may cause the pain to persist until the end of pregnancy or
may cause referred pain in the leg.
Only in exceptional cases does pain occur as a result of
an organic disorder of the spinal column. Of the rare cases where
this happens, the most common organic disorder during pregnancy
is a herniated
disc.
After giving birth, women often experience pain in the
lower part of the back. This is frequently due to one or more of
the muscular mechanisms referred to later on, but it can sometimes
be caused by luxation of the coccyx.
What is it that increases the risk of back pain during pregnancy
and labor?
There are several factors peculiar to pregnancy and labor that
can render you more liable to back pain, although there are few
studies that show which of these factors are most important:
In normal conditions, the balance of tension in the abdominal
and back
muscles helps keep the musculature straight in the same way
as the stays that support the mast of a sailing-ship.
Such relaxation is necessary to allow the womb (or "uterus")
to grow in the later stages of pregnancy. However, if the abdominal
muscles are weak before the pregnancy, then relaxation can occur
early. In fact, in the population at large lack of abdominal muscle
strength is also a factor that increases the risk
of pain appearing and lasting longer.
Relaxation of the abdominal muscles increases the tendency of
expectant mothers to bend backwards - in the hyperlordosis
posture (see further below) - and place too much demand on the back
muscles to keep their balance. The principle is rather like that
of a chair; it is stable when resting on all four legs, but if we
want to keep our balance on the two back legs only, then we have
to correct our posture constantly.
These mechanisms make it more likely for the muscles of the lower
back to spasm
and for pain to occur.
Hyperlordosis increases the load on the spinal column, and more
importantly forces the muscles in the lower back to work harder
than necessary. This makes them liable to spasm and can trigger
pain in this zone and/or referred
pain in the leg.
In some cases hyperlordosis can also overload the facetary
joint, and this can eventually be affected by a facetary syndrome.
This syndrome can also cause pain in the lower back and referred
pain in the leg. However, normally the overload has to be sustained
for much longer than a pregnancy for the facetary joint to be affected,
so that pregnancy is unlikely to cause pain in this way if the joint
is perfectly sound at the outset.
3. Weakness of the gluteal muscles.
In normal conditions, the gluteal muscles stabilize the pelvis
and provide stable support for the lower spinal column.
During pregnancy, as the weight increases and the posture of the
spinal column alters, if the gluteal muscles are too weak, they
may not be capable of steadying the sacroiliac joint, which joins
the column to the pelvis, and this can cause pain in the lower
back and the buttocks.
4. Sendentariness and repose. Some women are forced to
repose during pregnancy for gynaecological reasons. Others do so
from habit, without any medical reason to warrant it.
Sedentariness and repose in themselves increase the risk of
pain appearing
and lasting longer.
In normal conditions, the nerves detect the degree of tension
in the muscles. This information automatically keeps you aware of
your body posture, which helps you maintain the requisite postures
better and with less strain on the muscles. With repose, these nerves
lose their habit and cease to function properly, which makes you
more liable to adopt bad postures unconsciously and to overload
the muscles.
In normal conditions, there are reflexes that coordinate the
abdominal and back muscles so that you retain proper balance at
rest, and especially in movement. Training and activity keep these
reflexes in good repair. But contrariwise, repose makes it harder
for these reflexes to work properly and so increases the likelihood
of overloading the muscles.
Sedentariness and repose quite rapidly produce loss of muscle
strength and mass, which increases the likelihood over overloading
or lesion of the muscles.
5. Weight gain. In a normal pregnancy where the mother
follows the correct diet, there is no important weight gain until
after the fifth month, and this does not usually exceed 8 kilos
in all.
Weight gain forces the lower back muscles to work harder
and aggravates the tendency to spasm due to abdominal relaxation,
lordosis and repose, especially if the abdominal and back muscles
were not strong to begin with.
Moreover, in pregnancy the weight gain is concentrated in the
lower half of the body. This overloads the front part of the
vertebral disc, which in turn increases the pressure on the back
wall of the disc,
which is thinner than the front wall. This increases the likelihood
of a fissure,
protrusion or herniated disc, which can cause low back pain
and sciatica (irradiated pain in the leg).
In theory, weight gain can also aggravate pre-existing spondylolisthesis.
However, this does not normally happen if the spondylolisthesis
is mild - grades I and II - or the muscles are strong.
6. Problems of space.
The increasing volume of the uterus and the congestion of the pelvis
can increase the likelihood of compression
of a nerve root, causing sciatica (irradiated
pain in the leg).
7. Labor. Women often experience pain in the lower back
during and immediately after labor. There are several mechanisms
which can cause this.
Muscular strain: In some cases labor can entail a great
deal of strain, provoking a muscle
spasm that may last for several days after labor.
Alterations of the pelvic joints. . During labor, the
pelvis dilates to let the foetus emerge. In normal conditions,
this dilation is minimal and simply entails the relative separation
of the bones forming the pubis, at the front of the pelvis. There
are several possible causes of excessive dilation of the pelvis,
the most common being that the diameter of the mother's pelvis
does not match the size of the baby. Excessive dilation can affect
the sacroiliac joints at the back of the pelvis; which
join the pelvis to the spinal column. if this happens, it may
cause pain and muscle spasm in the lower back and buttocks.
Exceptionally, the strain of labor may cause a fissure,
protrusion or herniated disc. In that case, there may be low
back pain and/or sciatica (irradiated
pain in the leg).
Luxation of the coccyx. . If the foetus presses the coccyx
back during labor, stretching or breaking fibres in the ligament
binding it to the sacrum, the coccyx may be displaced. This is
known as "luxation of the coccyx". It can cause intense pain at
the base of the spinal column, especially when sitting on a hard
surface.
Can this have prejudicial consequences for the mother or the foetus?
Not for the foetus. And not normally for the mother. Only
in exceptional cases where there are pre-existing risk factors or
the right treatment is not administered in time, can the pain caused
by pregnancy or labor trigger off neurological mechanisms that
may cause the pain to persist, irrespective of what produced it.
However, with preventive measures and the right treatment, the
vast majority of the back problems that may arise during pregnancy
or labor can be prevented or satisfactorily treated.
Can back problems be so severe as to make pregnancy inadvisable?
They do not normally definitively rule out pregnancy.
There are some specific disorders of the spinal column that may
constitute temporary contraindications that are better dealt
with before becoming pregnant. Examples of these are:
Herniated
disc. The fact that Magnetic
Resonance detects a herniated disc is not in itself important
and definitely does not contraindicate pregnancy. However, if
the hernia produces symptoms, it is best to have it treated before
becoming pregnant. Otherwise, pregnancy will probably make it
worse.
Spondylolisthesis,
where it produces symptoms, is progressive or reaches grades III
or IV. If the spondylolisthesis is there but does not produce
symptoms, all that is needed is to religiously do the right exercises
to control it. There is a section of this site that shows effective
exercises for enhancing the strength, resilience or elasticity
of the back muscles. However, patients with spondylolisthesis
should be examined first by a doctor to determine what exercises
are appropriate in each case.
In some cases of post-surgical
fibrosis where the symptoms are especially intense, do not respond
to treatment and hinder rehabilitation of the muscles, the mother
must weigh her desire to become pregnant against the risk of increased
pain during pregnancy due to mechanical factors and the fact that
some treatments cannot be administered.
It is up to the potential mother and her doctor in each case to
assess the foreseeable effect of pregnancy and decide accordingly.
What to do to prevent or treat back pain during pregnancy.
Of the measures that are effective in preventing back pain, the
most important in the case of pregnancy and labor are:
- Avoid taking repose unless it is necessary for medical
reasons.
- Observe the rules of postural
hygiene.
- Do exercises
to train and strengthen the muscles that have an important function
for the back.
Some authors recommend the use of pelvic corsets (that
is, corsets worn around the hips rather than the waist) to assist
the gluteal muscles. Although there are no studies demonstrating
their effectiveness, they can be used during pregnancy and after
giving birth, when the pain at that moment is due to the effects
on the rear pelvic joint.
If you experience pain during pregnancy, although there are some
medications you cannot take because of the possible danger to the
foetus, there are treatments
that can deal with it satisfactorily in most cases. If the pain
does not respond to general measures, then neuroreflexotherapy is
a highly recommended option. |
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