During the second trimester of pregnancy, circulating levels of corticotrophin-releasing hormone (CRH) increase exponentially Ordinarily, such a surge would stimulate an overproduction of glucocorticoids in the mother. Pregnant women produce large quantities of a CRH-binding protein (“CRH-BP") that prevent CRH from being recognized and used by receptors. The situation changes in the last weeks of pregnancy.Blood levels of glucocorticoids rise dramatically in the last three weeks of gestation, CRH levels climb even higher but CRH-binding proteins diminish. .
I also agree with Jarosław Króliczewski. Unfortunately, Hasanain did not specify the species. So we can only suppose that the question relates to humans.
Chrousos, G.P. et al. (1998) Interactions between the Hypothalamic-Pituitary-Adrenal Axis and the Female Reproductive System: Clinical Implications. Ann. Intern. Med. 129, 229