Vaginal Birth Can Cause Blindness in retinopathic Type I diabetic?

[healthinfo6]

A pregnant 30 year old female type 1 diabetic has due date of November 6 and has retinopathy.
So far, no complications, but was hospitalized a couple of months ago with some odd false labor pains but nothing was concluded.
The allo doctors want to induce labor a week or so before due date.
Now, she has been told by her OBGYN that medical clearance is needed from a retinal specialist because if she has vaginal birth there's high-risk of her going blind because of the retinopathy. Now family is so worried that even with clearance maybe she should have a Caesarian birth regardless.
Has anyone EVER heard of this? Can the force of labor exacerbate retinopathy and cause blindness?
Thanks for any info, homeopathic and non.
Susan