Is sciatica preventable?

She can get a specific McKenzie Assessment of her back.
Even if she is currently symptom free she will usually have signs of the underlying problem (such as blockage or stiffness of certain back, hip and nerve movements). 
Sciaitca is simply a disc problem, but one where the disc bulges far enough to compress the nerve behind the disc (branch of the sciatic nerve, hence sciatica is the term for nerve symptoms down the leg along the path of the sciatic nerve). 
Changes in pregnancy such as the altered body shape and postures adopted can tip this underlying disc problem to become symptomatic and produce sciatica. 2/3 of the disc has no nerve supply, which means no pain is felt. This is the reason trivial things such as a bend forward early in the AM can trigger a major onset of back pain. The disc problem is there, but is not producing pain, and then something like this forward bend triggers it to start produce symptoms again.
A qualified McKenzie practitioner like myself (you can find one at www.mckenziemdt.org.au and search for a mckenzie practitioner in your state or country) can identify te particular problem, and teach you specific exericses and postural advice that could significnatly minimise the chances of getting the sciatica again.
if it did recurr, at least your wife could rapidly treat herself and ease it!

Back pain is common during preganancy.  It can resolve but often it does return.  It is important to strengthen muscles are your tummy (know as core muscles), watch the way she sits and learning a few key stretches to prevent a recurrence. 

As Joel mentioned above, this is where a McKenzie trained physiotherapist can help.  They perform a mechanical assessment to determine the key exericses which are applicable.  McKenzie therapists are always aiming to show clients how to stop the pain from coming back. 

To locate your closest McKenzie Method Physiotherapist, click here. 

Sciatica is preventable.  Unfortunately, sciatica is quite common during pregnancy although, when appropriately assessed by a professional, exercises can be prescribed to prevent and alleviate the discomfort associated with the sciatic nerve.  For further information or an appropriate exercise program, please feel free to contact me at any time (mary@btrehab.com.au).

Sciatica during pregnancy is preventable. During pregnancy, tendons become more flexible in preparation for birth. Unfortunately this may also increase the instability of the lower back and pelvic area. The lower back muscles tighten to try to stabilize the area and frequently irritate the sciatic nerve in doing so. A remedial massage therapist will release the spasmed muscles and show their client some simple stretches that can be performed at home safely whenever the tension builds up again. Massage will also ease the lower back ache associated with the addition weight being carried during pregnancy and assist with feet swelling, aching shoulders and other pregnancy-associated symptoms. 

Sciatica pain is due to compression of the sciatic nerve. In pregnancy this can be caused by pressure of the gravid uterus and in advanced pregnancy of the baby on the sciatic nerve. I once had a gynaecology patient who had severe sciatica and a large fibroid uterus filling her pelvis. I cured her sciatica by doing a hysterectomy.

Sciatica can be due to circumstances peculiar to that pregnancy such as how big the baby is, how the baby’s head is turned, how low in the pelvis the baby’s head is, etc. So it may not recur next pregnancy.

If there is a pre-pregnancy back problem that predisposes her to sciatica this can be exacerbated in pregnancy.