The New Sesquizygotic Twins and More: Exotic Twin Types/Twin Research Reviews: Parental Affection and Co-Twins’ Personality; Prenatal Demise in Twin Pregnancies; Heteropaternal Superfecundation; Selective Feticide in Dichorionic Twins/In the News: Identical Twin Oscar Winner; ‘Superfecundated’ Twins with Gay Fathers; Partly Living Apart; Which Twin Committed the Crime?

Abstract

AbstractThe second recorded case of sesquizygotic (SQZ) twins is summarized. It is suspected that SQZ twins result from the fertilization of an egg by two separate spermatozoa, followed by division of the fertilized ovum. Next, recent studies examining how differences in parental affection affect co-twins’ personality profiles, the prenatal demise of fetuses during twin pregnancy, a forensic case of heteropaternal superfecundation and selective feticide in dichorionic twins are reviewed. Finally, summaries of newsworthy items featuring an identical twin Oscar winner, a case of ‘superfecundated’ twins born to a gay couple, identical twins who try partly living apart and new molecular techniques to distinguish an innocent identical twin from his or her guilty co-twin are presented.