The effect of progesterone, oestrogens and hydrocortisone on the mitogenic response of lymphocytes to phytohaemagglutinin in pregnant and non-pregnant women.

The mitogenic response to phytohaemagglutinin of lymphocytes from women in the third trimester of pregnancy is not inhibited by progesterone, oestriol or oestradiol even at much greater than normal physiological levels. There was no difference in the response of lymphocytes from pregnant or non-pregnant women. Inhibition in the mitogenic response to phytohaemagglutinin was achieved with hydrocortisone but not at the physiological levels found in pregnancy. The results from this in vitro study would not support the view that the level of steroid hormones in pregnancy significantly affects the immunological status of the mothers.