“The 13/100K statistic implies that the ratio of #4 to #2 is about 13:100K. That does not imply that the ratios of #3 to #1, nor (#3+#4) to (#1+#2) are are similar.”
Yes, but since the everyone admits that the overwhelming majority of cases health isn’t the reason women get abortions, there is good reason to assume that the ratio of 3 to 1 would not be differ significantly from the ratio of 4 to 2.
But don’t believe me, check out the numbers. In Ireland, where abortion is illegal, the maternal mortality rate is a minuscule 2 per 100,000 birth.
Given the low frequency the matter actually comes into play, the maternal health risk issue is a complete red herring in the abortion debate. Brought up only to distract us from the real issue.
Sorry, but I don't think that argument works. Suppose that in a hypothetical community, there are 200,113 pepople broken down into the four categories thusly: 100,000; 100,000; 100; 13. You will observe that about half of pregnancies result in abortions, and that only 0.1% of abortions are of pregnancies that would otherwise be life threatening. Nonetheless, the ratio of #3 to #1 is not even close to the ratio of #4 to #2.
In reality, I suspect that the percentage of what would-be life-threatening pregnancies that end in abortion is nowhere near as large as in the hypothetical examine above, but the statistics you cited would not preclude that possibility.