DominiConnor, thanks for that explanation on conditional probability. Probability was never my strong suit and you put it in words what I could only understand instinctively.
I will grill them on the 10% as you suggested. But I do feel 90% IS an outright lie. The consultant was talking about VBAC and intervention rate (which includes cs, ventouse and forceps). I don't believe that any doctor can give 90% non-intervention rate even for first time mothers or mothers in general. I cross-checked the figure with a obstetrician friend, and she agreed that 70% is a more likely figure and depending on the hospital, some even have a 90% intervention rate!
I know what you mean about feeling like I have to win an argument with the hospital, rather than getting proper considered medical advice and presentation of risks.
It is not just the risk of intervention that I have to consider (whether it be 90%, 70% or 10%), it is the magnitude of the consequences should I fall on the wrong side of it. eg, the risk of uterine rupture in a VBAC is tiny, but the consequences of that risk being realised are catastrophic for mother and baby. Similarly, they might tell me I am at low risk for a second emergency cs, or forceps of ventouse, but if I am unlucky, then the consequences are unacceptable to me.
No one can dictate whether or not a risk is acceptable to me because, as Highlander says, I bear the consequences. Which is what riles me when a medical professional tries to pressure me, particularly on grounds of policy.
I like your approach about saying I will record their advice on whether VBAC is safer for mother and baby. Another thing I will ask is whether they can guarantee that VBAC will be safe for me and baby. Of course they can't. But it would put the fear of litigation into them.
Sad that it has to come to this ... and I hate to bring my profession into anything.