Relaxin, which may be an important hormone in pregnancy, is stimulated
by human chorionic gonadotropin. The exact role of relaxin in pregnan
cy is not completely defined, but it is known to be secreted by the co
rpus luteum, and its target areas in women are the uterine cervix, the
myometrium, the endometrium, and the decidua. Abnormal relaxin levels
have been associated with complications of pregnancy, and thus the pr
ecise role of relaxin in pregnancy needs to be a priority for further
research.