Beta-2-microglobulin (B2MG), has been reported as a biomarker for the fetal renal function development, including the maturation of the tubular reabsorption mechanisms. The aim of this work was to collate and integrate data from different clinical studies to describe the longitudinal changes in B2MG during pregnancy. Clinical data on maternal serum B2MG, fetal serum and urinary B2MG, and amniotic B2MG during normal pregnancy were fitted to mathematical equations to quantify B2MG changes at different gestational weeks (GWs). Data on maternal plasma B2MG levels during pregnancy between 6 and 40 GWs as well as in non-pregnant women were available from eleven studies. Data on B2MG levels in fetal plasma between 12 and 40 GWs were reported in ten studies. Retrieved data on fetal urinary B2MG levels were available from seven studies. Amniotic B2MG levels were available from thirteen studies. These data indicated a reduction in both fetal urinary and amniotic B2MG, while fetal serum was relatively constant. There was a slight (40%), increase in maternal serum B2MG during the third trimester. Continuous gestational dependent equations have been developed to predict the level of B2MG in these biological matrices at different GWs and can be integrated within feto-maternal system pharmacology tools. Current clinical data indicated that the maturation of fetal tubular reabsorption and catabolism begins in the middle of the second trimester of pregnancy. Further studies are required to elucidate these processes separately to prevent xenobiotic accumulation in the developing kidney and protect it from any possible nephrotoxicity.