<P> In females , relaxin is produced mainly by the corpus luteum , in both pregnant and nonpregnant females ; it rises to a peak within approximately 14 days of ovulation , and then declines in the absence of pregnancy , resulting in menstruation ) . During the first trimester of pregnancy , levels rise and additional relaxin is produced by the decidua . Relaxin 's peak is reached during the 14 weeks of the first trimester and at delivery . It is known to mediate the hemodynamic changes that occur during pregnancy , such as increased cardiac output , increased renal blood flow , and increased arterial compliance . It also relaxes other pelvic ligaments . It is believed to soften the pubic symphysis . </P>
<P> In females , relaxin is produced mainly by the corpus luteum , in both pregnant and nonpregnant females ; it rises to a peak within approximately 14 days of ovulation , and then declines in the absence of pregnancy , resulting in menstruation ) . During the first trimester of pregnancy , levels rise and additional relaxin is produced by the decidua . Relaxin 's peak is reached during the 14 weeks of the first trimester and at delivery . It is known to mediate the hemodynamic changes that occur during pregnancy , such as increased cardiac output , increased renal blood flow , and increased arterial compliance . It also relaxes other pelvic ligaments . It is believed to soften the pubic symphysis . </P>
when does the hormone relaxin start in pregnancy
when does the hormone relaxin start in pregnancy
14 weeks of the first trimester
14 weeks of the first trimester