Getting involved with research should not be seen as a way to cure your diabetes or to have a child. If they know you wish to have children they could actually refuse you for any study...
Normally the research companies will state their terms of criteria for age, sex, hba1c and pregnancy etc...
I do blood tests for research at QE2 hosp in Birmingham for 10 years. Just donate my blood and have general measurements etc done. If companies need blood from a female, long term diabetic.. My blood will be given...