text: Similar precision imaging studies have captured dynamic brain 
  reorganization across other neuroendocrine transitions, such as the 
  menstrual cycle (see review in ref. 28), underscoring the powerful 
  role steroid hormones have in shaping the mammalian brain29. Endo- 
  crine changes across pregnancy dwarf those that occur across the 
  menstrual cycle, which highlights the critical need to map the brain’s 
  response to this unique hormonal state. Broad physiological changes 
  occur in tandem with the rise in steroid hormones, including changes 
  in body mass composition, water retention, immune function and  The neuroanatomical changes that unfold during matrescence 
  may have broad implications for understanding individual differences 
  in parental behavior13,24,30,31, vulnerability to mental health disorders32,33 
  and patterns of brain aging18,19,34–36. Decreases in GMV may reflect 
  ‘fine-tuning’ of the brain by neuromodulatory hormones in prepara- 
  tion for parenthood26. For example, in rodents, steroid hormones 
  promote parental behavior by remodeling specific neural circuits in the 
  medial preoptic area of the hypothalamus. These behavioral adapta- 
  tions are critical to the dam’s ability to meet the demands of caring for 