Notably, whereas α2,6-linked sialylation remained relatively stable throughout pregnancy (Figure 4, bottom row), a drastic increase of α2,3-linked sialylation (e.g., per galactose on di- or triantennary glycans, respectively, A2GL and A3GL) was observed up to the third trimester (βA2GL = 1.11 ± 0.05; βA3GL = 1.16 ± 0.05), followed by a rapid return to baseline levels at the first time point after delivery (βA2GL = −1.19 ± 0.05; βA3GL = −1.42 ± 0.04) (Figure 4, top row).