In reviewing the literature initially:
Searches of Scholar for these phrases:
- 'physiological effects driving'
- 'women driving'
- 'ergonomics driving'
- 'pelvis driving'
- 'driving + ovaries'
...all returned no relevant studies discussing any effect of this kind, suggesting that if this kind of phenomenon has occurred, no one has thought it significant enough to study.
A search for 'driving pelvis' turns up one semi-relevant paper on the design of seats, according to the position of the pelvis. This paper, considering the ergonomics of driving position specifically related to the pelvis and published by a manufacturer of automobile and aerospace systems, doesn't specially address the supposed problems of women driving.
Additonally, a Scholar search for "dislodged pelvis" returns exactly 0 results, although without the quotes you find a number of irrelevant articles. A Google web search for "Dislodged pelvis" yields 106 results, of which one is this very question, and the majority of others concern either a dislodging during childbirth (which is of course an outward dislodging of the pelvis) or a dislodging after a fracture, which is a high energy traumatic injury, not really the kind of thing one might encounter whilst driving an uneventful route!
Finally, choosing a country in which women regularly drive (I've chosen the UK, because I'm used to perusing their health statistics, and with 30 million women, there's a decent sample size), there is not significantly high incidence of pelvic trauma at all regardless of gender. Code S33 of the 2012 Hospital Episode Statistics shows that during that year, 220 people were admitted with a dislocation, ligament damage or weakening, or strain to the the lumbar spine or pelvis, of which number 148 were male.
From this, it's easy to see that, at least in the UK (where approximately 66% of women hold a driver's licence, around 80% of women under 50 hold a licence), approximately 67% of those presenting at hospital with pelvis injuries of this type are male.
Taking into account that one cause of injury to the pelvis is giving birth, I think I can say with relative confidence that driving is very unlikely to cause injury to the pelvis of a woman in a significantly higher proportion than it does to men.
NB: I would have liked to address this with statistics from Saudi Arabia itself, but I was unable to find such detailed information for the country.