A new study by the Centers for Disease Control finds that birth rates are down in the United States and are currently at their lowest since 1986. But birth rates are different for younger versus older women.  Provisional birth rates declined for women aged 15–34 from 2017 to 2018 but rose for women aged 35–44.

Good news on the teen front

The CDC statistics show that birth rates declined for nearly all age groups of women under 35, but rose for women in their late 30s and early 40s. Teenagers are the age group with the biggest drop in birth rates, likely due to ongoing sex education in the classroom in order to prevent pregnancy as well as sexually transmitted diseases. The availability of birth control is likely another influence. The birth rate for teenagers aged 15–19 was down 7% in 2018. Rates declined for both younger (aged 15–17) and older (aged 18–19) teenagers. 

Birth rates for older moms increased

Probably the best news from this report shows that the pregnancy rate for women age 35 and older is increasing. With more women waiting until they are more settled in their career, trying to conceive well into their 30s and 40s, and taking advantage of fertility treatments such as IVF, the birth rates for this group continue to be on an upswing:

• The provisional birth rate for women aged 35–39 was 52.6 births per 1,000 women, up 1% from 2017 (52.3). The number of births to women in their late 30s increased by 2% from 2017 to 2018.
• The provisional birth rate for women aged 40–44 in 2018 was 11.8 births per 1,000 women, up 2% from 2017 (11.6). The rate for this age group has generally risen since 1982 by 3% per year (3,6). The number of births to these women increased by 2% from 2017 to 2018.
• The provisional birth rate for women aged 45–49 (which includes births to women aged 50 and over) was 0.9 births per 1,000 women, unchanged since 2015. The number of births to women in this age group rose 3% from 2017 to 2018. 

Overall cesarean delivery rates are down again

The overall cesarean delivery rate decreased further to 31.9% in 2018; the low-risk cesarean delivery rate decreased to 25.9%. Thus, cesarean rates returned to the lowest rate since 2009 (the rate peaked in 2009 at 32.9%) after an uptick in 2017. There was a wide range of overall cesareans between the states with Utah the lowest (Overall: 22.7% and low-risk 18.3%) and Mississippi the highest (Overall: 38.3% and low-risk 31.2%) cesarean rate.

The so-called "low-risk" cesarean delivery rate also decreased in 2018 to 25.9% of births from 26.0% in 2017. A low-risk cesarean is a cesarean delivery among nulliparous (first birth), term (37 completed weeks or more based on the obstetric estimate), singleton (one fetus), vertex (head-first) births. 

Source: Hamilton BE, Martin JA, Osterman MJK, Rossen LM. Births: Provisional data for 2018. Vital Statistics Rapid Release; no 7. Hyattsville, MD: National Center for Health Statistics. May 2019.