Successful diagnosis of fetal gender using conventional PCR analysis of maternal serum.

BACKGROUND Fetal DNA has been found in maternal plasma and serum. Diagnosis of fetal gender using maternal plasma and serum has been attempted in an effort to develop a new noninvasive method of prenatal diagnosis. METHODS Peripheral blood samples were obtained from 61 pregnant women at 10-17 weeks of gestation before amniocentesis. DNA was extracted from 800 microL of each plasma or serum sample. To detect the Y-chromosome-specific sequences DYS14 and DYZ3 in the maternal plasma and serum, 40 cycles of PCR were carried out for each DNA extract. The PCR products were analyzed by 2.5% agarose gel electrophoresis and ethidium bromide staining, and the results were compared with the results of the cytogenetic analyses of amniocentesis. RESULTS Cytogenetic analysis of amniocentesis revealed that 31 pregnant women had a male fetus and the remaining 30 pregnant women had a female fetus. Both DYS14 and DYZ3 were detected in 27 of the 31 plasma samples obtained from pregnant women carrying a male fetus and in all of 31 serum samples obtained from the same women. Neither DYS14 nor DYZ3 was detected in either the plasma or serum samples obtained from any of the 30 pregnant women carrying a female fetus. CONCLUSION PCR analysis of maternal serum can be used to diagnose fetal gender.