Trends in Fertility and Mother’s Age at First Birth Among Rural and Metropolitan Counties: United States, 2007–2017

October 17, 2018

Questions for Danielle Ely, Health Statistician and Lead Author of “Trends in Fertility and Mother’s Age at First Birth Among Rural and Metropolitan Counties: United States, 2007–2017

Q: Why did you decide to look at fertility rates and mother’s age at first birth among rural and metropolitan U.S. counties?

DE: Rural and metropolitan counties have a variety of differences related to general health, birth outcomes, and mortality rates. However, we noticed that recent research did not focus on the overall fertility differences in these areas or maternal age, which can affect birth outcomes. Looking at these items can help us understand why we might see differences between rural and metro counties in births and birth outcomes.


Q: How did the findings vary by race?

DE: Patterns for total fertility rates were similar by race and Hispanic origin. There were higher total fertility rates in rural counties than in metropolitan counties among the three race and Hispanic origin groups in 2007. In 2017, this pattern was the same for non-Hispanic white and Hispanic women, but non-Hispanic black women had higher total fertility rates in small or medium metro counties compared with rural and large metro counties. Hispanic women had the highest total fertility rates for each urbanization level in both 2007 and 2017

Non-Hispanic white, non-Hispanic black and Hispanic women had lower ages at first birth in rural counties compared with both metro county types. This was true in both 2007 and 2017, and differences between county types widened over this time.


Q: How did the findings vary by mean age of mothers at first birth?

DE: Mean age at first birth was lower in rural counties than small or medium metro counties and large metro counties from 2007-2017. Each of the three race and Hispanic origin groups had lower mean age at first birth in rural counties compared with metropolitan counties.


Q: Is there any comparable trend data prior to 2007?

DE: We have not computed trend data on total fertility rates or mean age at first birth by urbanization level prior to 2007.


Q: What is the take home message in this report?

DE: The important message in this report is that there are differences in the fertility rates and mean age at first birth between rural and metro areas, and these differences have gotten larger over time. These trends are generally the same by race and Hispanic origin. Information on differences in birth rates and maternal age by urbanization level can inform decisions on resource allocation and ultimately lead to improvement in infant and maternal health.

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Births: Provisional Data for 2017

May 17, 2018

Questions for Brady E. Hamilton, Ph.D., Demographer, Statistician, and Lead Author of “Births: Provisional Data for 2017

Q: What did you think was the most interesting finding in your new analysis?

BH: The report includes a number of very interesting findings. The general fertility rate, 60.2 births per 1,000 women aged 15–44, declining 3% in 2017 and reaching a record low is certainly noteworthy. In addition, the continued decline in the birth rate for teens, down 7% from 2016 to in 2017, and reaching another record low, is very significant. The increase in the cesarean delivery rate following several years of decline is noteworthy as are the recent increase in rates of preterm and low birthweight births.


Q: Why does fertility keep going down in the U.S.?

BH: In general, there are a number of factors associated with fertility. The data on which the report is based comes from the birth certificates registered for births in the U.S. While the scope of this data is essentially all births in the country, and provides detailed information about rare events, small areas, or small population groups, the data does not provide information about the parent’s decision to have (or not have) a child. And so, accordingly, we cannot examine the “why” of the changes and trends in births.


Q: Does the decline in the Total Fertility Rate essentially mean fertility is down below “replacement” levels?  Could you explain this in general terms?

BH: “Replacement” refers to a minimum rate of reproduction necessary for generation to exactly replace itself, that is, enough children born to replace a group of 1,000 women and their partners. For the total fertility rate, this rate is generally considered to be 2,100 births per 1,000 women. In 2017, the total fertility rate, 1,764.5 births per 1,000 women, was below replacement.


Q: Do the increases among women over 40 suggest a “new norm” in people waiting till much later to have children?

BH: Birth rates for women aged 40-44 and 45-49 years have increased generally over the last 3 decades. Given this, it reasonable to expect this trend to continue.


Q: Are the annual declines in teen pregnancy something that we are in danger of taking for granted?

BH: The birth rate for females aged 15-19 has decreased 8% per year from 2007 through 2017. For comparison, the decline in the birth rates for women aged 20-24 and 25-29 was 4% and 2% from 2007 through 2017. The decline in teen births is very noteworthy.


Q: Can you explain how the increases in preterm births and low birthweight are connected?

BH: Infants born preterm are also often, but not exclusively, born low birthweight and vice-versa.  The causes of the recent upward shift in these rates are not well understood.


Births: Final Data for 2015

January 5, 2017

Questions for Joyce A. Martin, M.P.H., Demographer, Statistician, and Lead Author on “Births: Final Data for 2015

Q: Was there a result in your study’s analysis of births in the United States that you hadn’t expected and that really surprised you?

JM: Although small, (from 9.57% to 9.63%) the rise in the preterm birth rate (births of less than 37 completed weeks of gestation) was unexpected. This rate had been declining steadily since 2007.

Also of note is the decline in the triplet and higher-order multiple birth rate, down 9% from 2014 to 2015, and a decrease of 46% since 1998. The year 2015 also is the third straight year of declines in the rate of cesarean delivery (rate of 32.0% in 2015).

The continued, large decline in the teen birth rate (down 8% from 2014 to 2015) was also somewhat surprising, although not unprecedented. From 2007 through 2014, the teen birth rates had declined 7% annually.


Q: What is the difference between this new births report and the other reports your office produced on 2015 birth data, like the preliminary data report on 2015 births and the Data Brief on teen births?

JM: The annual report “Births: Final Data for 2015” offers substantially more detail (e.g., age, race and Hispanic origin of mother, state) on key topics, than does the report on preliminary birth statistics (“Births: Preliminary Data for 2015”). The final report also includes information on topics not included in the preliminary reports such as multiple births, attendant and place of birth, birth order and birth rates for fathers.


Q: How has the number of births in the United States changed in 2015 from previous years?

JM: The number of births in the United States declined slightly in 2015 (by 9,579 births to 3,978,497) from 2014. The decline for 2015 followed an increase in births for 2014, which was the first increase since 2007.


Q: What differences, if any, did you see among race and ethnic groups, and among various ages?

JM: Of continued concern are the higher risks of poor birth outcomes as measured by levels of preterm birth and low birthweight among non-Hispanic black mothers compared with total births and other race and Hispanic origin groups. For example, in 2015 the preterm birth rate for births to non-Hispanic black mothers was more than 50% higher at 13.41% than for non-Hispanic white women (8.88%) and nearly 50% higher than the rate for births to Hispanic mothers (9.14%).


Q: Did you observe any regional or state differences in this study on births?

JM: Differences by state were observed for many of the demographic and medical/health items included in the 2015 final birth report. For example, from 2014 to 2015, the general fertility rate–which is the number of births per 1,000 women aged 15–44–declined in eight states and was essentially unchanged in the 42 states and the District of Columbia (DC). In 2015, the general fertility rate ranged among states from 51.1 births per 1,000 women aged 15–44 in Vermont to 78.2 in South Dakota.

Also, increases in preterm birth rates were limited to four states from 2014 to 2015: Arkansas, California, Nebraska, and North Carolina. Rates declined in four states: Montana, New York, Texas and Wyoming. Nonsignificant differences were reported for the remaining states and DC.


Women starting their families later in life

August 12, 2009

Did you know that in the United States, the average age of a mother at first birth has increased 3.6 years since 1970? Not only are U.S. women starting their families later in life, but the trend depends a great deal on a person’s race/ethnicity and where she lives. Also, the U.S. has a much lower average age at first birth than many developed countries. To read more about this, visit the new Data Brief from the National Center for Health statistics, “Delayed Childbearing: Women Are Having Their First Child Later in life.” Also, you can listen to the Statcast or ask questions of the author on this blog.


New birth statistics released–teen birth rate raises once again

March 18, 2009


New birth statistics released today by CDC’s National Center for Health Statistics (NCHS) reveal that the U.S. teen birth rate increased slightly in 2007 for the second straight year.
The findings are published in a new report, “Births: Preliminary Data for 2007,” based on analysis of nearly 99% of birth records reported to 50 States and the District of Columbia as part of the National Vital Statistics System.

The report shows that the birth rate for teens increased 1 percent between 2006 and 2007, from 41.9 births per 1,000 females ages 15-19 years in 2006 to 42.5 in 2007. Birth rates remained unchanged for younger females, ages 10-14, but increased for women in their twenties, thirties, and early forties.

For more information on births to unmarried women, preterm births, lowbirthweight, cesarean births, and more, visit http://www.cdc.gov/nchs/data/nvsr/nvsr57/nvsr57_12.pdf.


Mother’s Age at First Birth

July 19, 2007

One of the interesting demographic phenomena is the steady upwards creep in the age of women when they give birth to their first child.

In 1940 the age at first birth was 23.0 years. It dipped downwards to 21.5 in 1960 and was at 25.2 in 2004.

The data can be found here.