Precaution - If you have any of the following conditions while pregnant, then you should avoid henna: G6DP Deficiency (glucose-6 phosphate dehydrogenase deficiency), hyperbilirubinemia, anaemia, any chronic or acute condition which affects the your blood system, or any chronic or acute condition which affects your immune system. It is always wise to consult your doctor or midwife before using henna when pregnant