If I get an infection caused by gum disease, can that be transferred to my fetus?

Probably not. But any infection can sneak anyplace. So, getg it taken care of.
Preterm delivery. It is not that the baby will 'get' the infection, but women with peridontal disease have a higher risk of preterm delivery.
Preterm and low lbs . The constant inflammation your body produces due to gum disease or periodontal infection increases a chemical called prostaglandin. This has been linked to preterm and low birth weight babies. The hormonal changes during pregnancy make the expecting mother more succeptable to gum disease. Have regular cleanings and get the gums treated by a periodontist.
Early delivery. The main effect of the gum disease is your increased chance of having a pre-term baby.
Very slim chance . While the recent researches & publications in periodontology are heavily concentrating on the "perio-systemic" relationships, it is not still coming to a certainty that the mode of transference for the periodontal pathogens are always through the circulatory system, & in this case through fetal first pass bundle. There are some sporadic evidence only so far, and we need more solid evidences.
Probably not, but... The one thing medical science does know for sure is that women with gum disease do give birth to full term baby's with lower full term birth weights.So obviously there is some connection, but i don't have a direct answer to your question. Infer what you want from the answer .