Are there any substances that normally are used in toiletries that may adversely affect pregnant women.
A friend of mine who used to work in a Lush stop in town advised against buying anything with Lavender and other substances as they may induce labour.
Risking nothing I didn’t buy them, not wanting to harm my baby to be. Is there any truth to the claims? Are there any products/substances to avoid during pregnancy that can be found in toiletries or the like?
Ask your doctor. However, odds are you have nothing to worry about.
Rosemary is supposed to be another one to avoid; not sure if this is just accepted wisdom, or whether there’s any proper medical evidence that it causes any increased risks.
Pennyroyal oil gets used in some soaps. It’s also used as an abortifacient.
Herbalist with five years aromatherapy experience checking in. IANAD.
Lavender, to my knowledge, has never been implicated in inducing labor or miscarriage. There are certain essential oils you should avoid during pregnancy, but lavender isn’t one of them.
Here’s an excellent list of common essential oils to avoid. The ones labelled “possible irritant” are probably fine in a finished product or diluted in a carrier oil, unless you have very sensitive skin.
In general, finished commercial products contain very little essential oil - far below a true therapeutic dose. The rosemary in a rosemary salt scrub is not going to hurt you. But if it makes you anxious, just choose the honey and oatmeal one instead.
Squink, the pennyroyal oil incident I think you’re referring to was two girls who each drank an ounce of essential oil and died from it. It is very poisonous, and, like most essential oils, should never be taken internally for any reason.
WhyNot’s advice is bound to be excellent; she’s a new Mom with a sensitive preemie, so I’d imagine she’s honed her herbal knowledge for pregnancy and infants greatly. She didn’t toot her own horn in this regard, so thought I would. 
This site had some nice info: www.bayhousearomatics.co.uk/essential.htm I see there that spike lavender, L. stoechas, is listed, because of it’s higher camphor content. Most lavender species are considered the safest of essential oils, though.
As said, essential oils used in commercially prepared toiletries are already quite diluted, so there shouldn’t be need for alarm. I’ll have to add, there often seems to be an alarm for the toxicity of plant extracts, and caution is quite wise, but one should have an open alert for a lot of the synthesized chemicals in products we use as well.
Thanks WhyNot, elelle
Massage therapist who dabbles in aromatherapy weighing in.
AFIK, lavender (frequently regarded as the “desert island” oil, because if its safety and mulitplicity of uses) is perfectly safe for use during pregnancy. Aside from pennyroyal, which is seldom used in aromatherapy anyway, the oil I hear most about as being one you should avoid during pregnancy is marjoram.
Damn, if I had known this question was going to turn up on the SDMB, I would have brought my aromatherapy books home from work.
Aromatherapist checking in (see screenname).
Spanish Lavender, which is hard to find and not usually used in products is listed as an oil to avoid in the Essential Oil Safety Data Manual by Robert Tisserand. Spike Lavender has a similar chemical composition, and would probably make the list as well, but I’d have to check. The lavender essential oil used in most toiletries is L. Officianalus, and there are no contraindications for using it during pregnancy in the reference books I have.
I get asked this question a lot, and I have to say, there have been no extensive studies done on the use of essential oils in pregnancy. There have been no reports of complications in pregnancy due to the use of skin care products with safe dilutions of essential oils.
Of course, consult with your doctor for any questions you might have about your particular situation. The only note I’d make is that if you have problems with blood pressure, avoid rosemary e.o., which has been shown to raise blood pressure.
The biggest problem with using scented toilletries and what-have-you in pregnancy is that hormonal changes may make you very sensitive to scent in general. I’ve had more pregnant ladies tell me they couldn’t stand anything scented around them during the first few months. YMMV
But if you are uncomfortable using something, then let your conscience be your guide.