Identifying Oxytocin Deficiency in Pediatric Patients With Pituitary Disease

Inclusion criteria (participants with AVP-D): * AVP-D diagnosed in clinic using standard of care diagnostic tools; * Stable pituitary hormone replacement (no change in dose of hormone replacement in six weeks prior to baseline); * If on estrogen/progestin, female participants agree to stop for at least 6 weeks prior to Main study visits; * English language proficiency. Inclusion criteria (participants with hypopituitary disease): * Hypopituitary disease diagnosis; * If receiving pituitary hormone replacement, no change in dose in six weeks prior to baseline); * If on estrogen/progestin, participants agree to stop for at least 6 weeks prior to Main study visits; * English language proficiency. Exclusion criteria (all participants): * History of pulmonary embolism or unprovoked deep venous thrombosis; * History of breast/endometrial cancer as well as current therapies on estrogen modulators/blockers (i.e., tamoxifen, raloxifene, aromatase inhibitors); * History of stroke, transient ischemic attack, myocardial infarction, angina pectoris, or peripheral arterial disease; * Pregnancy or breastfeeding within the last 8 weeks; * Medication changes within 2 weeks of enrollment or within 5 half-lives of the respective medication; * History of stage 3 chronic kidney disease or cirrhosis; * Any significant illness or condition that the investigator determines could interfere with study participation, data collection or safety; * Active tobacco smoking or nicotine patch use; * Psychosis or active suicidality.