The short answer: most dermatologists suggest pausing hydroquinone during pregnancy. There's no strong proof it causes harm, but it's absorbed into the body far more than most creams, so guidance leans toward avoiding it until you've talked with your provider. This reflects positions from the FDA and the American Academy of Dermatology (AAD).
Hydroquinone is a topical skin-lightening ingredient. It's commonly used to fade melasma and dark spots, including the pregnancy-related pigmentation sometimes called the 'mask of pregnancy.' It works by reducing melanin production in the skin. In many places it's prescription-strength, though lower concentrations have appeared in some over-the-counter products.
The main concern is absorption. Research cited by dermatology sources estimates that roughly 35-45% of a topical dose can be absorbed into the body, which is high compared with most skincare ingredients. The FDA has classified it as pregnancy category C, and the AAD and melasma treatment guidelines commonly list pregnancy and nursing as reasons to avoid it. Existing human data haven't clearly shown birth defects, but the data are limited, so the consensus leans toward avoiding it rather than relying on thin evidence.
Many providers point to gentler alternatives with better pregnancy safety profiles. Azelaic acid is often recommended (FDA category B), and vitamin C, glycolic acid, and diligent sunscreen use are frequently suggested to manage pigmentation. It also helps to know that pregnancy-related melasma often fades on its own in the months after birth. Your dermatologist or obstetrician can help you build a plan that's safe for your stage.