We have investigated the use of a nested polymerase chain reaction assay for the detection of a fetal-specific Y-chromosomal sequence (DYS14) from DNA extracted from unsorted maternal peripheral blood. Serial dilutions of male DNA into female cord blood DNA indicated that the assay could detect an equivalent of a single male cell in 300,000 female cells. The assay exhibited absolute specificity for male DNA with no amplification from a DNA panel obtained from 10 female cord blood samples. When used on DNA extracted from unsorted peripheral blood from a series of pregnant women, the predictive values of a positive test for a male fetus were 86%, 67% and 87% in the first, second and third trimesters, respectively. We have also demonstrated that retesting the samples allows the detection of a proportion of male-bearing pregnancies with a high degree of accuracy, in that all 15 women who gave positive signals in two consecutive amplifications had male fetuses. We have also applied the test at 8 weeks postpartum to eight women who had previously delivered male babies; no Y-specific signal could be detected in any of them, suggesting that most women have cleared their circulation of fetal cells by 8 weeks after parturition.

Type

Journal article

Journal

Hum Genet

Publication Date

01/1993

Volume

90

Pages

483 - 488

Keywords

Base Sequence, DNA, False Negative Reactions, False Positive Reactions, Female, Fetal Blood, Gestational Age, Humans, Male, Molecular Sequence Data, Polymerase Chain Reaction, Predictive Value of Tests, Pregnancy, Pregnancy Trimester, First, Prenatal Diagnosis, Reproducibility of Results, Sensitivity and Specificity, Sex Determination Analysis, Y Chromosome