[fcallagy]

I agree with what Trux said above,AFAIK there is little or no solid information on this subject in relation to freediving or scuba as any tests would be unethical. Ama divers aside as they may have physiological adaptations from generations before them and what works for them may not work for others. If in doubt stay out my 2 cent in any case. I don't think any doctor would give any advise other than don't do it.
I am male so the above is very easy for me to say but I am sure there are other freediving mothers out there that could advise.
Congratulations in any case