For the serum N-glycosylation characteristics likely originating from the Fc portion of IgG (diantennary N-glycans without sialylation; A2S0) (15, 26), we confirmed with progressing pregnancy a decrease in fucosylation (A2S0F, βA2S0F = −0.59 ± 0.05) and increase in galactosylation (A2FS0G, βA2FS0G = 0.59 ± 0.04), both rapidly reversing after delivery (βA2S0F = 0.67 ± 0.04; βA2FS0G = −0.81 ± 0.04) (Figure 3, bottom row).