There are three commonly used methods of comparing abortion incidence across populations. The first and most widely used is the abortion rate. This is the number of abortions per 1,000 women of reproductive age, 15-44. Using New York State Population data and abortion data from 2013, the New York City abortion rate in 2013 was 15. According to the CDC, the US abortion rate in 2011 was 13.9.
The second method is what the CDC calls the abortion ratio. When the CDC says abortion ratio, they mean the number of abortions per 1,000 live births. In 2013 NYC had a CDC abortion ratio of 505. The US had a CDC abortion ratio of 219 in 2011.
The third method, which was included in the Guttmacher Institute’s most recent report on abortion statistics for 2011, is what they call the abortion ratio. When the Guttmacher Institute’s researchers say abortion ratio, what they mean is “abortions per 100 pregnancies ending in abortion or live birth,” which is to say, abortions as a percentage of all pregnancies excluding miscarriages. In 2013, NYC had a Guttmacher abortion ratio of 37%. The US had a Guttmacher abortion ratio of 21% in 2011.
That means that in New York City, 37% of all pregnancies except those which ended in miscarriage ended in abortion. In the Bronx, the abortion ratio reaches 45%. By all three measures, NYC has rates far beyond the national average. But the abortion ratio puts it in perspective: in parts of NYC, women choose to end nearly half of their pregnancies with abortion.