During pregnancy, all the hormones can make it so that melanocytes come to the surface, not only in that linea nigra, but you can notice darker areas in your skin and your face and other places.

孕期间，激素的变化会使黑色素细胞更加活，不仅会在妊娠中线处显现，还可能导致皮肤、其他位变得更深色。