Will it harm my baby if I have abscess teeth while pregnant?

Infection can spread. Disease of teeth and gums can affect health of a person in many ways, eg, difficulty eating, spreading infection, later chronic illness. If pregnant, a woman with dental disease should inform her OB and get dental care as soon as possible. The dentist and OB should share information before and after treatment, with patient's consent and involvement.
Possible. Any infection can be passed along to the unborn child. An abscessed tooth is infected and this is in your blood stream which is connected to your baby's. Get them taken care of.
Possibly! Abscesses teeth during pregnancy lends itself to the potential for blood poisoning and even you becoming septic! with your baby on board, that means you baby, too! if you have any doubts as to getting dental care while pregnant and have your oby-gynie set the treatment ground rules for the dentist! moms with periodontal disease have babies with lower birth weights and so this means abscesses, too!
It could. A few years ago the focus was on prevention of preterm birth by proper dental hygiene. This was explored by several investigators and, despite initial enthusiasm, getting rid of your carries does not really help prevent a preterm birth. So my answer would be: it does not hurt to have good dental hygiene, but do not count on it to prevent preterm birth.