Source: National Vital Statistics System, 2017
Source: National Vital Statistics System, 2017
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.
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.
Confidentiality concerns can impact adolescent and young adults’ access to sexual and reproductive health services. Young people who are covered by their parents’ private health insurance may be deterred from obtaining these services due to concerns that their parents might find out about it. Similarly, confidentiality concerns may arise because youth seeking such services may not have time alone during a visit with a health care provider.
A new NCHS report describes two measures related to confidentiality concerns and sexual and reproductive health care.
NCHS has released provisional estimates of selected reproductive indicators from birth data for 2014 through the second quarter of 2016. Estimates for 2014 and 2015 are based on final data.
The estimates for the first and second quarter of 2016 are based on all birth records received and processed by NCHS as of August 28, 2016.
Estimates are presented for: general fertility rates, age-specific birth rates, total and low risk cesarean delivery rates, preterm birth rates and other gestational age categories. These indicators were selected based on their importance for public health surveillance as well as the feasibility of producing reliable estimates using available provisional data. Future quarterly releases will include additional birth indicators from natality data.
Quarterly estimates are compared with estimates for the same quarter of the preceding year; for example, the second quarter of 2016 is compared with the second quarter of 2015. For comparability with rates for 12-month periods, the quarterly (3-month) rates have been annualized to present births per year per 1,000 population that would be expected if the quarter-specific rate prevailed for 12 months.
In addition, the rates and percentages for a 12-month period ending with each quarter (i.e., 12-month moving average) are presented to account for seasonality. Estimates for the 12-month period ending with the fourth quarter in each year can be interpreted as an annual provisional estimate for that year.
Gestational weight gain was within the recommended range for 32% of women giving birth to full-term, singleton infants in 2015, with 48% gaining more weight and 21% less weight than recommended.
Approximately 44% of women who were underweight before pregnancy gained within the recommendations, compared with 39% of women who were normal weight, 26% of women who were overweight, and 24% of women with obesity before pregnancy.
Weight gain above the recommendations was highest among women who were overweight (61%) or had obesity (55%) before pregnancy.