Purpose: to analyze the occurrence of conjoined twins at a tertiary perinatology reference university hospital over a period of 25 years (January 1982 to January 2007) and to describe the successful separation of one of the pairs.
Methods: we consulted retrospectively the database of the University Hospital of the Medical School of Ribeirão Preto, University of São Paulo, Brazil, in order to determine the number of pairs of conjoined twins, their frequency, classification, gender, type of pregnancy resolution, attempted surgical separation, prenatal diagnosis and survival.
Results: we detected 14 pairs of conjoined twins (1/22,284 live births and 1/90 pairs of twin live births) born during this period (six males, seven females and one of indeterminate sex).