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n. A female hormone secreted by the corpus luteum that helps soften the cervix and relax the pelvic ligaments in childbirth.

n. A peptide hormone of the insulin superfamily.

n. hormone secreted by the corpus luteum during the last days of pregnancy; relaxes the pelvic ligaments and prepares the uterus for labor

"In addition, there is a hormone called relaxin that "relaxes" all your joints to enable these structural changes to occur."

endocrine    internal secretion    hormone