I confess that I knew the figures were totally false - but the overriding concern was to get the laws eliminated, and anything within reason that had to be done was permissible.
As this interesting article by David van Gend explains, it seems that it is advances in medicine, and not legalisation, which has caused a dramatic decline in deaths from abortion procedures. It was due to improvements in medicine, rather than any changes to the law, that deaths from illegal abortions declined from about 100 a year in Australia in the 1930s to just 1 in 1969.
Meanwhile, very extensive research from Finland shows that women who undergo abortions are 6.5 times more likely to suicide in the following year than women who completed the pregnancy. (There are graphs showing the research results here.)
So it certainly should not be assumed that legalising abortion leads to a lower female mortality rate. First, because illegal abortions have been made safer by modern medical treatment, and second, because legalisation increases the total number of abortions, which increases the total number of female deaths by suicide.