Pregnancy is a whirlwind of hormonal fluctuation: in addition to oestrogen, relaxin and progesterone are key players when it comes to physiological changes in your body. These hormones prepare you for birth and labour by loosening your joints and muscles, ligaments and supporting tissues. You may notice an increased joint mobility, particularly in the pelvic area, as the sacroiliac joints (SI joints) and pubic joint become looser, to allow the pelvis to open during birth. Due to the loosening of ligaments and the weight gain, it is not unusual for the arches of your feet to also lower. This in turn also affects the position of your whole body.