Chromosomal abnormalities are one of the factors known to interfere with no
rmal embryo development; thus preimplantation genetic diagnosis (PGD) for c
hromosome anomalies may be a new tool for improving the pregnancy rate in s
elected groups of patients. Embryos from three groups of patients (control,
aged and recurrent miscarriage patients) were screened by PGD using specif
ic DNA probes for chromosomes 13, 16, 18, 21, 22, X and Y. The control and
aged groups were included in the PGD study because the women carried sex-li
nked genetic disease. The frequencies of chromosome anomalies observed in o
lder women (46.3%) and in recurrent miscarriage patients (53%) were signifi
cantly higher (P < 0.05) than the frequency in the control group (19.3%). A
fter PGD screening and transfer of normal embryos, pregnancies were obtaine
d in women who had undergone repeated abortions (approximate 25% pregnancy
rate per transfer) but not in older women. On the basis of these data, it s
eems that PGD screening of embryos can help some women undergoing repeated
abortions, as these techniques allow successful pregnancies to be obtained
or, if no pregnancy can be obtained, the results may help the couple to dec
ide whether to enter an embryo or gamete donation programme.