Women resort to dyeing their hair to change its color or to hide the white hair that results from aging, and hair dyes are composed of chemicals at different concentrations, and there are several types of hair dyes; Temporary dye that does not penetrate the hair shaft, and disappears after washing the hair once or twice, and the second type is the semi-permanent dye that penetrates the hair shaft and almost disappears after Washing hair five to ten times, and the last type is permanent (oxidative) hair dye, and it is the most famous type that women usually use, as the dye penetrates the hair shaft and makes a permanent change in it, and the color remains until it falls The hair is replaced by a new hair, and it is worth noting that the darker the color of the dye, the more colorful chemicals it contains. 
Damage to hair dye on a pregnant woman
Research based on the study of hair dye damage during pregnancy is still limited, but some studies have shown that there is a relationship between the use of hair dyes during pregnancy or one month before pregnancy and the increased incidence of children with neuroblastoma ,  while studies have shown Another is that the woman's body absorbs a very small amount of the chemicals in hair dyes, and this percentage does not pose a threat to the fetus, and the percentage that pose a risk to the fetus is much greater than that of hair dyes, but many doctors advise that a pregnant woman should avoid dyeing her hair During pregnancy, especially in the first trimester, it is recommended to replace chemical hair dyes with henna , as this is safer for the health of the fetus.  
Tips when dyeing hair during pregnancy
Many specialists advise to postpone dyeing hair after childbirth due to the lack of sufficient evidence and studies on this subject as mentioned, but if a woman insists on dyeing her hair during pregnancy, then she should follow the following advice:   
- Follow the instructions included with the hair dye.
- Wear special gloves while mixing the dye and applying it to the hair.
- Dye hair in a well-ventilated room.
- Not to leave hair dye on the head for a period exceeding the period specified in the instructions, and it is preferable to apply the dye for the shortest possible time.
- Wash hair and rinse the scalp well after completing the hair dyeing process.
- Try to dye hair tuft without access to the scalp, because the dye is absorbed if it reaches the scalp head and not the hair itself.
- Do not mix different types of hair dye products together.
Henna as an alternative to dye during pregnancy
You can resort to using henna as an alternative to dye during pregnancy, but there are some tips that women should follow when using henna, including the following:   
- Ensure that the type of henna used is safe for the fetus. As there are many types of henna .
- The use of pure natural henna , which often lasts for one to four weeks, and it should be noted that black henna cannot be natural, so it is worth avoiding its use.
- Performing an allergy test before completing the hair dyeing process, to ensure that you do not experience allergic reactions to the product.
- Avoid using henna that contains para-phenylenediamine (PPD), which can cause a serious allergic reaction to the skin for some. The allergic response may last for months and it is often difficult to diagnose and treat. It is worth noting that black henna contains this matter.
- Read the ingredients of henna or dye before using it, to make sure that all its materials are safe and that the woman does not suffer from any sensitivity to any compound present in it, and not to use henna of unknown ingredients and source.
Using hair dye while breastfeeding
There is insufficient evidence on the extent of the effect of hair dye on the mother's milk and thus on the nursing child , but because the amount that is absorbed into the blood is small, the possibility of harm to the infant is small, and it should be noted that no cases have been recorded as a result of using hair dye during breastfeeding . However, studies are still ongoing to give definite results on this topic. 
Damage to hair dye on women in general
Some studies have shown that there is a relationship between the use of hair dyes and the incidence of some types of cancer , while other studies have shown that there is no relationship between the use of hair dyes and cancers, and in general the manufacturers of hair dyes have reduced the use of substances that have been found to be carcinogenic when studied in animals, except In general, it is advised to reduce the use of hair dyes, or start using them only when the appearance of white hair, or to use natural alternatives to dye hair, with emphasis on the importance of following the instructions attached to the packages of hair dyes, and it is worth noting that doing the patch test before using any dye is necessary, and the test is performed by placing a small amount of hair dye behind the earOr on the inner part of the elbow, and then wait until the dye dries up. If signs of allergy appear or the woman feels uncomfortable, the dye should not be used, in order to avoid the occurrence of contact dermatitis or allergic reaction or an allergic reaction. : Allergic Reaction).  
- ^ A b "Hair Dyes" , Www.cancer.org , 27-3-2014, Retrieved 26-10-2017. Edited.
- ^ McCall EE, Olshan AF and Daniels JL (16-8-2005), “Maternal hair dye use and risk of neuroblastoma in offspring.” , Www.ncbi.nlm.nih.gov , Retrieved 8-11-2017. Edited.
- ^ A b t "Is it safe to use hair dye when I'm pregnant or breastfeeding?" , www.nhs.uk , 11-5-2015, Retrieved 26-10-2017. Edited.
- ^ A b "Hair Treatment During Pregnancy" , Www.americanpregnancy.org , 4-3-2017, Retrieved 8-11-2017. Edited.
- ↑ "Pregnancy week by week" , www.mayoclinic.org , 13-7-2017, Retrieved 26-10-2017. Edited.
- ↑ [ http://americanpregnancy.org/pregnancy-health/tattoos/ “Tattoos When Pregnant”], www.americanpregnancy.org , Retrieved 11-11-2017. Edited.
- ↑ "Temporary Tattoos, Henna / Mehndi, and" Black Henna ": Fact Sheet" , www.fda.gov , 4-18-2001, Retrieved 8-11-2017. Edited.
- ↑ "Hair Dye Safety" , www.webmd.com , Retrieved 7-11-2017. Edited.
- ↑ "Hair dye reactions" , www.nhs.uk , Retrieved 7-11-2017. Edited.