It is quite common to get backache during pregnancy.
Due to physiological changes during pregnancy, the ligaments in the body naturally become softer and stretch for preparation of labour. This can put strain on the joints of the lower back and pelvis, which can cause back pain.
Reasons for Backache
During a healthy pregnancy, women typically gain between 25 and 35 pounds. The spine has to support that growing weight. That can cause lower back pain. The weight of the uterus due to growing baby also puts pressure on the blood vessels and nerves in the pelvis, back and lower limbs.
Pregnancy shifts the centre of gravity. As a result, gradually the body begins to adjust your posture. This may result in back pain or strain.
During pregnancy, the hormone called relaxin that allows ligaments in the pelvic area to relax and the joints to become looser in preparation for the birth process. The same hormone can cause the ligaments that support the spine to loosen, leading to instability and pain.
Emotional stress can cause muscle tension in the back, which may be felt as back pain or back spasms.
Things to do to avoid backache
both knees should be bent and back should be straight while lifting or picking something up from the floor
lifting heavy objects should be avoided
Move feet while turning to avoid twisting the spine
should wear flat shoes to evenly distribute the body weight
Keep back straight and well supported while sitting at work and at home
Should get enough rest, particularly later in pregnancy.