All these things have a very bad effect on that developing embryo and that developing fetus. Now, what do we mean by medicinal drugs? Well, these are those legal drugs that you can get in a pharmacy or you can get at the physician's office. And for example, one very common type of medicinal drug is aspirin. This basically is used to relieve headaches, to relieve different types of pains and so forth. Now, almost every single type of medicine will have some type of effect on that developing fetus as long as that medicine can get across as long as that drug can get across the membrane of the placenta.