Foetal death and injury due to maternal injury was a largely invisible but important component of child injury mortality, he said.
"The problem remains hidden, and under-reported, because of the way foetal trauma is coded in vital statistics and the lack of pregnancy status recorded in crash and injury surveillance systems."
The research was published in the latest issue of the journal Australian Epidemiologist.
Prof Weiss said there needed to be more attention paid to reporting and preventing maternal injuries and adverse foetal outcomes.
Ministry of Transport data showed that from the early 1990s to the mid 2000s the average annual distance driven per woman for ages 15-39 increased by about 40 per cent to 7000 km, which contributed to increased exposure to the risk, Prof Weiss said.
He recommended a combination of increased protection for vehicle occupants, less driving and less risky driving to suit different lifestyles.