A new study suggests that women who have babies from donor-egg pregnancies have fetal cells in their systems years after giving birth.

In a small study of 11 healthy women, researchers found that fetal cells from a donor-egg pregnancy survived for at least nine years after five of the mothers gave birth. All five of the women had delivered boys.

The finding is significant because fetal cells from a donor egg pregnancy are genetically foreign to the mother, as half are from the father and half from the egg donor.

Fetal cells live for decades in a mother following a normal pregnancy, but that is due to the fact that half of the genetic material comes from her.

Because the mother did not reject the foreign tissues, these findings could be a first step toward developing treatments from stem cells donated by embryos.

The study was conducted by researchers from Brigham and Women's Hospital in Boston. The findings were published in the online edition of Fertility and Sterility.

Abstract

Objective

To determine whether allogenic fetal cells resulting from donor egg pregnancies persist in maternal circulation.

Design

Nested polymerase chain reaction (PCR) amplification of the DYS14 sequence, a region of the Y chromosome, from DNA purified from peripheral blood cells.

Setting

Academic medical center.

Patient(s)

Healthy 18-60-year-old women who have had donor egg pregnancies resulting in a male offspring (n = 11) or, as a control, female offspring (n = 8), at least 1 year previously and without any other source for male cells in their peripheral blood or a healthy male.

Intervention(s)

None.

Main Outcome Measure(s)

Detection of DYS14 sequence by nested PCR.

Result(s)

DYS14 was detected in 5/11 (45%) of women who had donor egg pregnancies resulting in a male offspring, but in 0/8 (0) of women who had donor egg pregnancies resulting in a female offspring. The longest interval between delivery of a male offspring and detection of the DYS14 gene was 9 years.

Conclusion(s)

Unmatched, allogenic fetal cells from donor egg pregnancies are able to persist in the circulation of healthy women for at least 9 years after delivery. This implies a novel mechanism by which immunologic detection is avoided by these cells and may impact on how they may be used for regenerative and transplant medicine.

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