Although we see children in our practice, a few of our patients are actually new mom's to be. They are usually those in their older teens or young twenties. We sometimes end up caring for these new mom's dental health.
Now, when a woman is pregnant, there are a lot of obvious hormonal changes. Dentally this can manifest as bleeding gums. The best preventative there is closer attention to good oral hygiene and a good diet.
Sometimes ladies develop a red purple bump or swelling on the gums called a pregnancy tumor (which sounds scary, but is benign).
It is best to avoid x-rays or medications especially during the first trimester, so we may delay any treatment or routine diagnostic x-rays a few months. Hopefully, the patient has good oral health so that little problems will not turn into bigger ones because of treatment delay. I'm sure there are many other good sites with information for expectant moms. In fact, here is one from the: ADA. Things are not always so easily planned but, if you are thinking about starting a family, make sure your dental treatment needs are in good order beforehand.
Oh, and don't forget to schedule your baby for their first dental visit by age one!