Women aged 50 and over—There were 677 births to women aged 50 and over in 2013, up from 600 in 2012 (Tables 2 and 6) (14). The number of births to women in this age group has generally increased since 1997 (144), when data for women aged 50 and over became available again. The birth rate for women aged 50–54 was 0.7 births per 10,000 women in 2013, up from 0.5 in 2012 (data not shown in tables). Because of the small number of births to women in this age group, the birth rate for women aged 50–54 is expressed per 10,000 women. For rates shown elsewhere in this report, births to women aged 50 and over are included with births to women aged 45–49 when computing birth rates by age of mother (the denominator for the rate is women aged 45–49). The increase in birth rates for women aged 35 and over during the last 20 years has been linked, in part, to the use of fertility-enhancing therapies (17,18).