Size of testes, ovaries, uterus and breast buds by ultrasound in healthy full-term neonates ages 0–3 days

Background Hormonally sensitive organs in the neonate can change size within days of birth as circulating maternal estrogen wanes. Although several reports document the size of these organs through infancy, few focus attention on the near-birth period. Clinical and research evaluation of hormonal and genitourinary disorders would benefit from reference size standards.