Proenkephalin neurons in the adBNST mitigate stress-induced anxiety and estrous cycle disruption in female mice.

Musculoskeletal (MSK) pain encompasses a broad group of conditions affecting the muscles, bones, joints, ligaments, tendons, and associated soft tissues, and is commonly characterized by pain, reduced mobility, and functional limitations . According to the World Health Organization, musculoskeletal disorders are a leading contributor to disability worldwide, significantly affecting individuals’ physical function and quality of life . During pregnancy, MSK pain is highly prevalent, affecting approximately 50–70% of pregnant women globally, with reported variation depending on population characteristics and assessment methods , , . The most frequently affected anatomical regions include the lower back, pelvic girdle, hips, and, less commonly, the neck, shoulders, wrists, and lower extremities. Low back and pelvic girdle pain are particularly common, with prevalence estimates ranging from 34% to 72% , . The etiology of pregnancy-related MSK pain is multifactorial. Hormonal changes—particularly increased levels of relaxin and progesterone—result in ligamentous laxity and joint instability. In addition, gestational weight gain and an anterior shift in the center of gravity lead to altered biomechanics and increased mechanical stress, especially in the lumbopelvic region , . These physiological adaptations collectively increase susceptibility to pain and functional impairment.