Rapid prenatal determination of fetal sex by polymerase chain reaction on amniocyte DNA.

Sex determination in early gestation is important for fetuses at risk for X-linked disorders or congenital adrenal hyperplasia. One hundred and seventy consecutive samples of amniocytes were collected between the 12th and 31st gestational week. Seven women received early amniocentesis before the 14th week. Fetal sex was determined by amplification of Y-specific DNA fragments within five hours. All results of the polymerase chain reaction, except for one false-negative, were compatible with cytogenetic analyses. Polymerase chain reaction of amniocyte DNA provides a rapid technique for sex determination in early gestation with high specificity and sensitivity.