Intrauterine diagnosis of sex chromosome aneuploidy.

OBJECTIVE: To provide current information on sex chromosome aneuploidies to obstetricians who encounter such diagnoses and who counsel prospective parents faced with the prenatal diagnosis of a sex chromosome aneuploidy. DATA SOURCES: Unbiased information about the natural course of sex chromosome aneuploidy has become available only in the last few years. Current knowledge is based on seven prospective studies on unselected individuals with sex chromosome aneuploidy identified 20-30 years ago. All literature on sex chromosome aneuploidy was reviewed. Karyotypes specifically addressed included the following: 47,XXY, 47,XXX, 47,XYY, 45,X, 45,X/46,XX, 46,XX/47,XXX, and 46,XY/47,XXY. METHODS OF STUDY SELECTION: The international studies followed the affected subjects from birth to young adulthood. All published reports, case studies, and articles were reviewed. TABULATION, INTEGRATION, AND
RESULTS: All prospective studies were included in the course of determining necessary information for obstetricians and prospective parents. Points addressed for each of the aneuploid karyotypes included expected phenotype, reproductive competence, developmental risks, and intervention therapies.
CONCLUSION: Information about sex chromosome aneuploidy can assist obstetricians in providing accurate and comprehensive genetic counseling to parents of affected fetuses, and thereby facilitate the process of making an informed decision about pregnancy management.