Abstract
The complement system of normal human serum (NHS) manifests
a strong, dose dependent embryotoxic potential when administered
to chick embryos inducing, among others, also malformations
of the brain. We have demonstrated, however, that the degree
of complement-induced embryotoxicity varied remarkably in the
course of the menstrual cycle of fertile healthy women, although
the complement serum activity (CH100) exhibited no significant
fluctuation. On the other hand, the variation of embryotoxicity
appeared negatively associated with progesterone levels. Following
our results high progesterone levels occurring physiologically
in luteal phase of the menstrual cycle suppress the embryotoxic
action of the complement system.
