A True Hermaphrodite Chimera Resulting from Embryo Amalgamation after in Vitro Fertilization

Abstract

High rates of successful pregnancy after in vitro fertilization depend on placing more than one embryo into the mother, a practice resulting in a 30-to-35-fold increase in dizygotic-twin deliveries.1 Increased frequencies of twin-associated anomalies might also therefore be expected. Chimerism, the presence in a single person of cells derived from two or more zygotes, is one such rare anomaly. It is usually ascertained through anomalous blood-grouping results or (for XX/XY chimeras) sex reversal or intersex. We used DNA polymorphisms to investigate a 46,XX/46,XY hermaphrodite conceived by in vitro fertilization. We found not only that the child is a chimera, but . . .