Melajour Skin Rejuvenating Serum contains Vitamin C, 4-n-Butylresorcinol, Hyaluronic Acid, and L-Glutathione. While most of these ingredients are generally safe during pregnancy, 4-n-Butylresorcinol is a skin-lightening agent with limited safety data in pregnant women and may not be recommended. The serum is free from hydroquinone and parabens. Still, due to the presence of 4-n-Butylresorcinol, it’s best to avoid using it during pregnancy unless your doctor specifically approves it.