Sister-chromatid exchanges in newborns after normal and progesterone-treated pregnancies.

Two groups of newborns were selected for SCE analyses, one consisting of infants born after progesterone-treatment during pregnancy (PTP) and a control group. A slight, but statistically significant difference in the number of SCEs was found: in the control group 5.55 +/- 0.62, and in the PTP group 7.99 +/- 0.88. This effect also proved to be true in an in vitro system, where various concentrations of progesterone were tested. The authors offer two possible explanations: one involving the biochemical pathways of progesterone and the influence on the level of excretory products; the other involving a direct relationship between progesterone and DNA.