Ó Breasail M, et al. - The neonatal skeleton contains 20 to 30 g calcium (Ca) at birth. Per hypothesis, fetal skeletal development may involve maternal bone mineral mobilization, researchers here sought for evidence of pregnancy‐induced mineral mobilization. Healthy pregnant (n = 53) and non‐pregnant non‐lactating (NPNL; n = 37) women aged 30 to 45 years (mean age 35.4 ± 3.8 years) were recruited. Peripheral quantitative CT (pQCT) and high‐resolution pQCT (HR‐pQCT) scans from the tibia and radius were obtained at 14 to 16 and 34 to 36 weeks of pregnancy, with a similar scan interval for NPNL. Both groups exhibited decrease in volumetric bone mineral density (vBMD) outcomes; however, pregnancy‐related decreases for pQCT total and trabecular vBMD were greater. Decrease in HR‐pQCT total and cortical vBMD compared with NPNL was observed; both groups had similar magnitude of trabecular vBMD decrease. Compared with NPNL changes in bone microarchitecture, pregnancy‐related changes significant exceeded for trabecular number, trabecular separation, cortical thickness, and cortical perimeter. At the proximal radius, there was increase in cortical vBMD and endosteal circumference vs NPNL, whereas there was decrease in cortical thickness. Higher total and compartment‐specific vBMD decreases were observed in relation to pregnancy vs age‐related change at the distal tibia. Changes at the radius were only evident with pQCT at the cortical‐rich proximal site and suggest endosteal resorption. Although these pregnancy‐related changes in the appendicular skeleton are small in magnitude, if they indicate global changes across the skeleton at large, they may contribute substantially to the Ca requirements of the fetus.