- ABC Club - The largest German organisation for families with higher multiple birth children, from triplets onwards.
- Malta Multiple Connection - Multiple Connection is a Malta based support group offering support to families of twins, triplets and multiples on the Maltese islands.
- National Organization of Mothers of Twins Clubs, Inc. - Official site; a non-profit, nation-wide support group for parents of twins and higher order multiple birth children.
- The Association of Finnish Triplet Families - Mostly in Finnish, but has an English section and lots of international links.
- Twins Plus Singapore - Support group for parents of twins and other multiples in Singapore.
