Note: always speak first to your doctor or pediatrician before you apply henna if you are pregnant or breastfeeding. That being said, henna has been used for pregnancy body art for thousands of years. The pregnant figure, the rounding, developing bellies, are regularly painted with body art henna in India and the Middle East. And have been for thousands of years. Unless you have specific allergies to henna-based products, dyeing your hair while pregnant will cause zero problems. There are No harsh, noxious chemicals like traditional, conventional hair dyes. All plant-based, organic, and natural.