January 30,2014 — Summary of "Shifts in Intended and Unintended Pregnancies in the United States, 2001-2008," Finer/Zolna, American Journal of Public Health, Dec. 19, 2013.
HHS in its Healthy People 2020 initiative set the goal of reducing unintended pregnancy rates as a means of improving the nation's health. Since estimates were last published in 2006, there have been several notable developments that can affect unintended pregnancy rates, including the release of more precise population estimates, the start of the economic recession in 2007 and a slight increase in use of highly effective, long-acting contraceptive methods, according to Lawrence Finer and Mia Zolna of the Guttmacher Institute.
In this study, Finer and Zolna estimated intended and unintended pregnancy rates among all women of reproductive age and among various subgroups between 2001 and 2008.
The researchers defined unintended pregnancies as those that were mistimed or unwanted, while intended pregnancies were those that women desired at the time they occurred or sooner, or about which the woman felt indifferent.
The researchers relied on data from Guttmacher's previously published studies and the National Center for Health Statistics' 2006-2010 National Survey of Family Growth (NSFG) to calculate rates of unintended births, miscarriages and abortions. They used population data from the U.S. Census Bureau.
Specifically, the researchers calculated the total number of unintended pregnancies by adding the number of unintended pregnancies ending in birth, miscarriage and abortion, then dividing the sum by the population of women of reproductive age, which was defined as ages 15 to 44. The process was repeated for several population subgroups.
The researchers found that 51% of the nearly 6.6 million U.S. pregnancies in 2008 were unintended, with an unintended pregnancy rate of 54 unintended pregnancies per 1,000 women of reproductive age.
Although there was little change in the overall pregnancy rate between 2001 and 2008, the researchers observed "a small shift from intended to unintended pregnancies." The intended pregnancy rate decreased to 51 per 1,000 women, while the rate of unintended pregnancies rose to 54 per 1,000.
Meanwhile, the percentage of unintended pregnancies ending in abortion decreased between 2001 and 2008, from 47% to 40%, while the rate of such pregnancies ending in birth increased to 27 per 1,000 women.
The study also found that existing disparities in unintended pregnancy rates by education, income and relationship status increased.
When the researchers analyzed the results based on age, they determined that the proportion of unintended pregnancies in 2008 decreased as age increased, with the rates of unintended pregnancy and unintended pregnancy ending in birth highest among women ages 18 to 24.
Among unmarried women, the proportion of pregnancies that were unintended was more than twice the proportion for married women. Cohabitating women had the highest unintended pregnancy and unintended birth rates. Rates of intended pregnancy, unintended pregnancy and unintended births increased significantly among cohabitating women during the study period, while rates of unintended pregnancies ending in abortion decreased substantially.
The researchers also noted large disparities across income levels. The lowest-income women had a total pregnancy rate more than triple that of women with the highest incomes, and they had an unintended pregnancy rate more than five times that of the highest-income group. The researchers observed a clear shift from intended to unintended pregnancies among the lowest-income women; the shift was slighter among other women who had low incomes but were not in the poorest group.
Further, the report showed that women with a college degree were less likely to have an unintended pregnancy than those who did not have a college degree. Women who had not completed high school had the highest rates of unintended pregnancy and unintended birth. However, this group also had a lower proportion of pregnancies ending in abortion, compared with women with a high school degree or higher.
In addition, the study showed that rates for both unintended pregnancy and unintended birth for minority women were more than twice the rates for white women. Black women had the highest unintended pregnancy rate, while Hispanic women had the highest unintended birth rate.
Finally, the study found that unintended pregnancy rates were highest among women with no religious affiliation. Among those with a religious affiliation, the proportion of unintended pregnancies that ended in abortion was highest among Catholics.
"Our results indicate that unintended pregnancy is a stubborn problem in the United States," the researchers wrote, noting that "[b]etween 2001 and 2008, there was a slight shift from intended to unintended pregnancy."
Although the poor economy "likely indirectly lowered women's pregnancy intentions," the researchers emphasized that disparities in unintended pregnancy rates by relationship status, income and education are "dramatic and growing." They added, "The differentials by subgroup suggest that solving the problem of unintended pregnancy will require more than just the efforts of public health professionals; addressing fundamental social inequities in income and education are also essential."
They also noted that "[p]ersistently high" unintended pregnancy rates could be evidence of "a complex interplay of shifts in the timing of partnering and childbearing, changes in desire for pregnancy, and changes in contraceptive use-effectiveness." As people increasingly tend to marry and bear children at later ages, "the period after childbearing -- during which sterilization or other highly effective long-acting methods are typically used -- has become shorter," while the period between first intercourse and first birth -- during which less-effective methods are typically used -- has lengthened.
The authors suggested that research should continue to explore various questions, "both quantitative and qualitative," surrounding the issue of unintended pregnancy, such as how women's reproductive "desire[s]" differ by relationship status and economic level; identifying the "biggest obstacles to effective contraceptive use"; and the effects of the Affordable Care Act's contraceptive coverage requirements.
"Answering some of these questions may bring us closer to the goal of enabling all women and couples to become pregnant when they want and avoid pregnancy when it is not desired," they concluded.