I have been part of the Harvard Nurses Health study II for many years. They are now coming out with the NHS III. Any nurses who want to join this and are between 22 and 45 can become part of it by going to www.nhs3.org
This can be passed on to any female nurses one knows who might be interested. The survey you fill out is usually only once a year. They do a newsletter and also over some of the results of what they find in the large no of people involved.