Pregnancy can cause back pain due to changes in your body as your baby grows. Most pregnant women experience back pain, especially in the second half of pregnancy. The pain typically occurs where the pelvis meets the spine, at the sacroiliac joint. Some common causes include weight gain, posture changes, hormone changes, and muscle separation. To alleviate back pain, you can try exercises that strengthen your back and abdomen, maintain good posture, wear comfortable shoes, and avoid lifting heavy objects. Applying heat or cold packs, using support belts, and getting a gentle massage may also help. If back pain persists, consult your doctor before taking any medication. Acetaminophen (Tylenol) is generally safe, but avoid NSAIDs like ibuprofen or aspirin. In rare cases, severe back pain may be related to conditions like pregnancy-associated osteoporosis or vertebral osteoarthritis, so it's important to see a doctor if you experience severe or rhythmic pain.