Scientists have discovered that a sizeable minority of women have Y-chromosome gene sequences in their blood. This is interesting because as you may know, Y-chromosomes are the chromosomes that belong to men, so ladies, what are they doing there, and where did they come from?
An obvious answer would be from pregnancy with a male son, every woman who has been pregnant still carries cells from her fetus within her bloodstream. Cells from the pregnancy will reside within the mother’s bloodstream and organs for the rest of her life. Even if the pregnancy was terminated or if there was a miscarriage these said genes would remain with the Mother. There is a name for this so-called condition, it is called microchimerism (1), which is named after the Greek chimera, a mythical, monstrous fire-breathing animal that is composed of the parts of three animals a lion, a snake and a goat. Okay so that explains it, well at least it does for the women who have given birth to sons. But what about the women without sons that still had male cells in their bloodstream?
This called for a study (2) that was done by immunologists at the Fred Hutchinson Cancer Center in 2004. In this study they took samples from 120 women who had never had sons. They found that 21% of these women had male DNA. The women were then categorized into 4 groups according to pregnancy history: Group A had only daughters, Group B had had one or more miscarriage(s), Group C had induced abortions and Group D had never been pregnant before. The prevalence of male michrochimerism was considerably greater in Group C although it was still present in each group. Group A 8%, Group B 22%, Group C 57% and Group D 10%.
The conclusions of this study noted that the possible sources of male michrochimerism included, known pregnancies, miscarriages, vanished male twin, or sexual intercourse. This means, that through intercourse alone there is a potential for women to hold onto male genes and DNA within their organs and blood stream for their entire life!