Dr. Kim Foster: Wicked Health


Is It Safe To Dye Your Hair When You're Pregnant?

Do you have to choose between beauty and health?

Is it safe to colour your hair when you’re pregnant? Many, many women wonder about this. And, as with so many things, there is a lot of rumour out there, a lot of urban myth, and a lot of confusion. Is hair dye harmful to your developing baby? How much gets absorbed? Are there safe alternatives?

So let’s clear some stuff up.

One of the reasons why this is a tricky issue is because we have limited research on the topic. Mostly, this is due to the obvious ethical conflict of subjecting women and their unborn babies to unknown, potential risk. That said, we can still make some recommendations.

First thing to know: there is very limited absorption of the chemicals used in hair dye through your skin. This is true, unless you have burns or open sores on your scalp. Or unless you’re eating the stuff (which, by the way, I heartily discourage.)

Motherisk is our gold-standard source of information on all things related to pregnancy and safety. It’s run by the awesome folks at Sick Kids in Toronto, and it’s the go-to resource for physicians when we need to advise women on these sorts of issues.

Motherisk reviewed 25 studies on the subject of hair treatments and pregnancy, and concluded that hair treatments are “unlikely to cause adverse fetal effects.” There are no known or identified risks or birth defects that have been linked to hair chemicals, and “for the average pregnant woman, receiving hair treatments 3 to 4 times during pregnancy does not appear to increase risk of adverse effects on the fetus.”

One of the most convincing lines of research, in my opinion, are the studies that look at hairdressers themselves: a population that is exposed to hair chemicals on a more or less daily basis. One such study compared 550 hairdressers to a control group of women never exposed, and they found “no statistically significant differences in fetal loss, preterm birth, small for gestational age babies, congenital malformations, or achievement of developmental milestones among their children.”

All of this is extremely reassuring. Years of experience and observation, coupled with the existing research, tells us that there is no cause for concern.

Bottom line: colouring your hair when you are pregnant is considered safe.

Of course...the thing about research is that there’s always new stuff coming to light. Although this is how things look right now, I cannot promise that we will never find any data that contradicts the basic position that colouring your hair is safe.

So what to do?

Well, for what it’s worth, I continued to highlight my hair throughout both my pregnancies. But “throughout” means every 3 months...so that meant a total of 3 times during pregnancy. I avoided the first trimester, when most of the critical fetal development is happening. And I only did partial highlights. This was not particularly science-based, but it was a personal choice, and I just felt better about it.

Which is no small thing, and ultimately, what I want you to consider.

You have to weigh things for yourself, personally: it’s important to feel good about yourself when you’re pregnant. Maybe, for you, that means taking particular care of your appearance and colouring your hair. Or, maybe for you that means not having to worry about a potential, unknown risk. It has to be up to you.

(For more reading on harmful stuff in pregnancy, read about the effects of stress in pregnancy, and pregnancy nutrition dos and don’ts.)

So...what do you think? Did you colour your hair during pregnancy? Was it something you worried about? Would you make a different decision if you were pregnant today? And—for you preggos out there—has this post changed your mind about colouring your hair?