Its job done, however, relaxin lingers in female bodies for up to a year, when softer ligaments make new mothers more prone to injury, as Jessica Ennis-Hill, an Olympic champion heptathlete, discovered in training after giving birth in 2014.

然而，正如杰西卡·恩尼斯-希尔（奥运会七项全能冠军）于2014年分娩后在训练中发现的那样，松弛素在女性体内会持续起作用长达一年之久，这时较软的韧带会使新妈妈们更容易受伤。