This is a poor statement I feel. How is it more dangerous? You drive once, and have a baby once, one for once the giving birth is vastly more dangerous.
Historical average death rate for the mother alone would approach 10%, and in 3rd world countries, it is still over 1%. For driving the death rate is something like 20 per 100,000, or as a better measure, something number of tens or hundreds of millions of KM of driving per death.
But, yes, giving birth can involve complications.