Twinstuff Outreach, our 501(c)(3) non-profit charity benefitting families with multiples in need, has begun an ongoing research project to develop the world's most comprehensive registry of twins. Thanks to the kindness of an initial grant from the Cardinal Health Foundation, we have developed the following survey to help populate our twins registry. The purpose of this database is to assist researchers who are seeking twins to interview for scientific medical research projects.

All researchers must contact Twinstuff Outreach via one of the contact methods listed below and then receive approval from our Board of Directors for access to this registry information. No other third parties or non-scientific researchers will be granted access to the actual information submitted in these surveys. Twins who fill out this survey who are later contacted by researchers will be free to determine whether they wish to participate in these specific research projects on an individual basis.

This survey should be completed separately by each twin (ages 18-and-older only, please) and will take approximately 15-20 minutes to complete. Parents who are filling out the survey for their children under the age of 18 who are twins should not fill out this survey but should instead start by filling out the following linked survey.

The first part of this survey is general background information. After filling out all required fields and hitting the 'send' button at the bottom of this page, you will be taken to part two of our survey in which you will be asked some questions to help determine your zygosity.