The most recent published estimates of the numbers and rates of abortions and pregnancies among teenagers, by state and race, were for 1988.1 Since then, the Centers for Disease Control and Prevention (CDC) and the National Center for Health Statistics (NCHS) have reported on teenage pregnancy rates or birthrates by state, but neither has provided a complete picture of all relevant measures.

In the CDC report, pregnancy rates are presented for 1991 and 1992 among women younger than 15, 15-17 and 18-19; the report also includes rates for black women and whites among all those aged 15- 19.2 However, the published data do not include abortion rates or abortion ratios. Moreover, the pregnancy rates are based on abortion data that are imperfect in several respects. Abortion reporting is incomplete in most states: In half, 13-51% of ab ortions are missed.3 In addition, the data have not been adjusted for women who obtain abortions out of state and do not include estimates for the nine states with no information on the age distribution of women having abortions.

The NCHS report shows trends in teenage birthrates by state from 1990 to 1994 and has 1994 breakdowns by race and ethnicity.4 However, it contains no estimates of pregnancy rates.

This article provides an update of national trends in rates of abortions and pregnancies among women aged 15-19 through 1992 (the latest year for which data are available) and births through 1995. It also presents the most accurate available estimates of state-level teenage abortion and pregnancy statistics.

Methods

The data sources and methods of estimation used in this study are the same as those used for the 1988 calculations. Birth data were taken from publications of the NCHS,5 which obtains birth certificate informat ion from state vital statistics agencies. The most recent NCHS data tabulate race according to the race of the mother rather than the child, and the NCHS has retabulated data from the 1980s in the same way; consequently, the birthrates presented here for the 1980s by race differ from those published previously. Racial groups other than white and black are not shown separately because of small numbers and the heterogeneity of this population. Hispanics may be of any race, and the figures for whites include the large majority of Hispanics.

Surveys conducted by The Alan Guttmacher Institute (AGI) of all known abortion providers in the country were the source for the annual number of abortions.6 Information from the surveys was available for 1980 173;1982, 1984-1985, 1987-1988 and 1991-1992; data for other years were interpolated, taking into account trends in the totals compiled by the CDC. Sample surveys of physicians and hospitals indicate that the AGI surveys miss some providers that perform small numbers of abortions; the result may be a 3% undercount of abortions.

National totals according to race and age were estimated using the distributions published by the CDC, with adjustments for year-to-year changes in the reporting states.* To estimate the distribution of abortions by race according to age, we applied iterative proportional fitting to calculate cell percentages that are as close as possible to the percentages in the CDC's age-by-race table, but that add up to our separate age and race distributions. We used the same procedure to estimate the age-by-ethnicity and age-by-marital status distributions.

For each state, we used data the CDC obtained from the state health statistics agency to determine the percentage distribution of women who had abortions in the state in 1992 by their state of residence. In 10 states for which CDC data were unavailable, w e asked a sample of abortion facilities for information about the state of residence of their patients.† To estimate the number of nonresidents who had abortions in each state, we applied the percentage d istribution of women having abortions, by their state of residence, to our count of the total number of abortions that took place in the state.

The proportions of abortions in each state that were obtained by women younger than 15, 15-17 and 18-19 were calculated from data published by the CDC.7 For the eight states whose health statistics ag encies did not have this information available, we estimated the proportions from data for neighboring states or nearby states that were similar in racial distribution and degree of urbanization. These proportions were then applied to the number of abortions obtained by residents of each state to yield the number of abortions obtained by teenagers in each state.

Information on the race of teenagers having abortions was unavailable for 14 states and the District of Columbia, and Hispanic ethnicity was unavailable for 31 states and the District of Columbia. No estimates were made for these jurisdictions, but the national estimates assume that their distributions are similar to those of the states with data.

The numbers of teenage abortions estimated in this way are generally higher and more accurate than those published by the state statistics agencies. Nevertheless, some inaccuracy can occur if the age distribution of women whose abortions are not reported to the states differs significantly from the distribution of those whose abortions are reported. Additional inaccuracy can result if the age distribution of residents who have abortions outside a state differs from that of women having abortions in the state.

In general, out-of-state abortions should not introduce large errors because, according to our calculations, 94% of U.S. residents who have abortions obtain them within their home state. However, state laws requiring parental consent or notification when minors are seeking abortions may cause a higher proportion of young women to travel outside their state for services. Consequently, in the 21 states that had such laws in 1992,‡ the estimated number of minors having abortions may be too low; in the neighboring states, to which minors might have traveled to obtain abortions, the number may be too high. Thus, the estimated abortion and pregnancy numbers and rates should not be used to assess the impact of parental involvement laws on minors' abortion and pregnancy rates.

Pregnancies, births and abortions are shown according to the woman's age at the time of the pregnancy outcome, not at the time of conception. Therefore, the data exclude pregnancies that began when the woman was 19 but ended when she was 20, while they include a small number of pregnancies that began when the woman was 14 and ended when she was 15. The numbers and rates of pregnancies include an estimated number of miscarriages and stillbirths.§

The population estimates used to calculate rates were obtained from the Census Bureau. Small differences in state rates, particularly those by race and ethnicity, should be viewed with caution because of variability in the estimates of state population sizes and the numbers of abortions and, for rates based on small populations, because of the possibility of random fluctuations. To minimize the latter problem, rates based on populations of less than 500 were not calculated.

The proportion of females aged 15-19 who have ever had sexual intercourse was taken from surveys conducted in 1976, 1982, 1988 and 1995, and was interpolated for the intervening years.8 Small differences per 1,000 sexually experienced teenagers should be interpreted with caution because of uncertainties introduced by the interpolations and the margin of error in the surveys.

In examining the geographic patterns of the statistics, we refer to the standard census groupings of states into four regions (Northeast, Midwest, South and West), each of which consists of at least two divisions.**

Findings

National Trends

In all, 112 pregnancies occurred for each 1,000 women aged 15-19 in 1992; 61 of these pregnancies ended in births, 36 in abortions and 15 in miscarriages (Table 1). When births and abortions are recorded according to the woman's age at conception, the rate is 130 pregnancies per 1,000 (not shown). About half of teenage women are not sexually experienced and therefore not at risk of pregnancy. For teenagers who had ever had intercourse, the pregnancy rate was 216 per 1,000. These rates mean that about 11% of young women aged 15-19 and 22% of those who were sexually experienced had a pregnancy that ended in 1992.

Black teenagers had 2.4 times the pregnancy rate of whites in 1992 (219 vs. 93 per 1,000), 2.2 times the birthrate (112 vs. 52 per 1,000) and 2.7 times the abortion rate (76 vs. 28 per 1,000). White teenagers' birthrate and abortion rate were reduced when Hispanic teenagers were excluded (to 42 and 25 per 1,000, respectively—not shown), but they were still higher than those of teenagers in most developed countries.9 Hispanic teenagers' birthrate was close to that of blacks, and their abortion rate was between those of whites and blacks (Table 2).

Unmarried teenagers, with a pregnancy rate of 93 per 1,000, accounted for 79% of pregnancies among women aged 15-19; they had 97% of abortions and 70% of births (not shown). *†10 The abortion rate among unmarried young women was somewhat higher than that for married teenagers (36 vs. 26 per 1,000).

Rates have fluctuated considerably since 1980. From 1980 to 1987, the pregnancy rate fell by 4% (from 111 to 107 per 1,000) and the birthrate declined by 5% (from 53 to 51 per 1,000), while the abortion rate changed little. By 1990, however, the pregnancy rate had risen by 10%, to 117 per 1,000, a level higher than any other since 1972, when abortion statistics became available. Between 1987 and 1991, the birthrate climbed by 23% (from 51 to 62 per 1,000), and the abortion rate declined by 10%. By 1995, the birthrate had fallen back to 57 per 1,000 (not shown), still well above the 1987 level. The abortion rate also declined in 1992, and preliminary data suggest that it has continued to fall since then.11

For sexually experienced teenagers, the pregnancy rate fell from 247 to 206 per 1,000 between 1980 and 1987. It then began to climb, reaching 223 per 1,000 in 1990 before declining again, to 216 per 1,000 in 1992.

Among white teenagers, the trends in pregnancy rates and birthrates followed the overall pattern, dropping until 1987, then rising sharply to peaks in 1990 and 1991, respectively. The birthrate then drifted down 5% (to 50 per 1,000) by 1995. Excluding His panics, the birthrate declined 7% between 1990 and 1994, the latest year for which data are available. The abortion rate of white teenagers tracked the birthrate in a slow decline until 1987, then plateaued until 1989 and fell by 19% through 1992.

Nonwhite teenagers' pregnancy rate changed little between 1980 and 1986, but their birthrate fell 7% because of a 10% increase in the abortion rate. From 1986 to 1991, the birthrate rose 16% among nonwhites, a smaller change than occurred among whites (25%). Over this period, the abortion rate fell 9%, accounting for some of the increase in the birthrate. From 1991 to 1995, the birthrate declined by 17%, to 82 per 1,000 (not shown). Almost half of the drop occurred between 1994 and 1995. Among black teena gers alone, there was also a 17% drop in the birthrate, to 96 per 1,000, a level close to the lows of the mid-1980s.

Among Hispanic teenagers, both the abortion rate and the birthrate increased between 1990 and 1992 (Table 2). Like white teenagers, Hispanics experienced only a small birthrate decline between 1992 (107 per 1,000) and 1995 (106 per 1,000—not shown).

Another way to understand teenagers' reproductive behavior is to look at the proportion of pregnancies terminated by abortion (the abortion ratio). Of the 15-19-year-olds who had a birth or an abortion in 1992, 37% had an abortion. The proportion was about the same for young women aged 15-17 and those aged 18-19 (38% and 36%, respectively—not shown).

Once pregnant, black teenagers were about as likely as non-Hispanic white teenagers to end their pregnancy by abortion (40% and 38%, respectively). Hispanic teenagers were less likely to do so (29%).

Between 1980 and 1987, the national abortion ratio hovered around 45-47% for all teenagers and for whites. Among nonwhites, the ratio rose from 42% to 45%. After 1987, it dropped sharply for white teenagers (from 45% to 35%) and less steeply among nonwhites (from 45% to 40%). No trend was evident among Hispanics over the three years for which data were available.

State-Level Statistics

Nationally, there were 960,000 teenage pregnancies in 1992 (Table 3, page 118). The numbers in each state largely reflect the size of the teenage population: California, Texas and New York had the largest number of both teenagers (not shown) and teenage pregnancies (154,000, 80,000 and 70,000, respectively). The fewest teenage pregnancies were found in states with relatively small teenage populations: North Dakota, Vermont and Wyoming (1,300-1,400 pregnancies).

As Table 4 (page 119) shows, the five highest pregnancy rates per 1,000 women aged 15-19 were in the West*‡: California (159), Nevada (145), Hawaii (138), Arizona (133) and New Mexico (129). The next five highest rates were in the South: Georgia, Florida, Texas, Mississippi and North Carolina. The lowest rates were in geographically scattered states: Minnesota, New Hampshire, North Dakota and Utah. Of the other rates that ranked among the lowest 10, four were in West North Central states (Iowa, Nebraska, South Dakota and Wisconsin) and two were in New England (Maine and Vermont). The rates among women aged 15-17 and 18-19 followed similar patterns by state; the correlation between the pregnancy rates of the two age-groups was high (r=.96).

Differences between the rates shown here and those reported by the CDC illustrate the effects of the incompleteness of the CDC data. For example, according to the CDC, Georgia had the highest pregnancy rate for women aged 15-19, while our data show five states with rates higher than Georgia's. The CDC shows a rate of 77 pregnancies per 1,000 teenagers for Maryland and 23 states with higher rates; our data indicate a rate of 118 per 1,000 (or 103 per 1,000 when miscarriages are excluded, as in the CDC data) and only 12 states with higher rates.

Overall, the birthrate among women 15-19 years old was 61 per 1,000 in 1992; the rate per 1,000 teenagers varied from 84 in Mississippi to 31 in New Hampshire. Six of the 10 highest birthrates were in the South (Alabama, Arkansas, Georgia, Louisiana, Mississippi and Texas), three were in Mountain states (Arizona, New Mexico and Nevada) and one was in the Pacific division (California). The 10 lowest birthrates were in five New England states (Connecticut, Maine, Massachusetts, New Hampshire and Vermont), four West North Central states (Iowa, Minnesota, Nebraska and North Dakota) and one Middle Atlantic state (New Jersey).

Statewide rates for women aged 15-17 and women aged 18-19 followed similar patterns, with some minor differences. For example, Arizona and New Mexico replaced Mississippi as the states with the highest birthrates among women 18-19.

Patterns of abortion rates were distinctly different. The highest rates per 1,000 women 15-19 years old were in Hawaii (67), California (64) and New York (60). The 10 highest rates were in three Pacific states (California, Hawaii and Washington), three South Atlantic states (Delaware, Florida and Maryland), two Middle Atlantic states (New Jersey and New York), Connecticut and Nevada. The 10 lowest abortion rates were in relatively rural states: four in the West North Central division (Iowa, Minnesota, North Dakota and South Dakota), four in the South (Kentucky, Louisiana, Oklahoma and West Virginia) and two in the Mountain division (Idaho and Utah).

As with pregnancy rates and birthrates, the relative rankings of the states with respect to abortion rates among 15-17-year-olds and 18-19-year-olds are similar (r=.97, excluding states for which the proportion of teenage abortions was estimated). The same 10 states have the highest rates for both age-groups, and differences among the 10 states with the lowest rates are generally minor. One exception is Kentucky, which has the eighth lowest rate for women 18-19 but the 20th lowest for 15 73;17-year-olds. The reason for the relatively higher rate among the younger teenagers may be the lack of a parental involvement law in Kentucky in 1992 and the ability of minors from Indiana, Ohio and West Virginia to avoid restrictions in those states by obtaining abortions in Kentucky.

Abortion rates showed much greater variation by state than did birthrates. The highest rate of abortions per 1,000 teenagers (67, in Hawaii) was 7.4 times the lowest rate (9, in Utah), while the highest birthrate per 1,000 (84, in Mississippi) was only 2.7 times the lowest rate (31, in New Hampshire).

The proportion of teenage pregnancies that were terminated by abortion also varied considerably by state—from 57% in New York to 16% in Utah. The abortion ratio tended to be highest in the states with the highest abortion rates. Of the 10 highest abortion ratios, three each were in New England (Connecticut, Massachusetts and Rhode Island) and Pacific states (California, Hawaii and Washington), and two were in the Middle Atlantic division (New Jersey and New York); the remaining two were in Maryland and Nevada. Except Massachusetts and Rhode Island, these states also had the highest abortion rates.

Two of the lowest abortion ratios were in Utah and Idaho, possibly in part because these states have large populations of Mormons, who generally value high fertility and oppose abortion. The remainder of the 10 lowest abortion ratios (including three that tied for 10th) were in four West South Central states (Arkansas, Louisiana, Oklahoma and Texas), five states elsewhere in the South (Kentucky, Mississippi, Tennessee, South Carolina and West Virginia) and South Dakota.

For comparison, the last column of Table 4 shows the 1988 pregnancy rate for women aged 15-;19. *§ In general, the rates were similar in the two years (r=.95). However, decreases of 10% or more occurred in six states, all in the Northeast (Connecticut, Maine, Massachusetts, New Hampshire, New Jersey and Vermont), and increases at least that large were found in the District of Columbia and three states (Mississippi, Montana and Rhode Island).

For U.S. teenagers as a whole, the birthrate was 15% higher in 1992 than in 1988; all but three states (Maine, Maryland and New Hampshire) also had higher rates in 1992. The District of Columbia experienced by far the greatest increase—57%. Rates were 20 -27% higher in five states: California, Colorado, Iowa, North Dakota and Rhode Island.

Between 1988 and 1992, the national abortion rate among women aged 15-19 decreased by 18%. Only Mississippi and the District of Columbia registered increases, while nine states had declines of more than 30% (Iowa, Louisiana, Maine, Minnesota, New Hampshire, Ohio, Oklahoma, Utah and Vermont).†*

There was a slight but not statistically significant tendency for decreases in abortion rates to be associated with decreases or below-average increases in birthrates. New Hampshire, for example, had the largest proportional decrease in both its birthrate and its abortion rate. On the other hand, Iowa and North Dakota saw little change in their pregnancy rates but large increases in birthrates and decreases in abortion rates. Thus, while changes in pregnancy rates generally affected both births and abortions, a reduction in abortions was associated with an increase in births in some areas.

Race and Ethnicity

White women aged 15-19 had 616,000 births, abortions and miscarriages in 1992 (Table 5), or 66% of all pregnancies among teenagers. Black women had 286,000 pregnancies (31% of the total), and Hispanics had 177,000 (19%). Among white and Hispanic teenagers, the largest number of pregnancies undoubtedly occurred in California, but racial and ethnic breakdowns are unavailable for that state. Of the states with data, Texas accounted for the largest number of pregnancies among white and Hispanic teenagers, and New York reported the largest number among blacks.

Among white teenagers in states with data, pregnancy rates and birthrates tended to be highest in the West and Southwest. To some extent, this could reflect a concentration of Hispanics in those areas. Many of the lowest rates were in the West North Central states, but abortion data by race were unavailable for New England states other than Rhode Island. Of the six highest abortion rates, four were in the West (Colorado, Hawaii, Nevada and Washington), one was in the Northeast (New York) and one was in the South (Maryland). By far the lowest abortion rate among white teenagers was in Utah. The next lowest rates were in rural states with small populations (Idaho, North Dakota, South Dakota and West Virginia); these were followed by rates in Missouri and Ohio.

For black teenagers, the highest pregnancy rates were in Wisconsin and Minnesota. A third midwestern state (Missouri) also had one of the highest rates, as did three states in the Northeast (New Jersey, Pennsylvania and Rhode Island). The highest birthrates among black teenagers also were in Wisconsin and Minnesota, and four more of the 10 highest rates were in the Midwest (Illinois, Iowa, Kansas and Missouri). The lowest pregnancy rates were in the South and West (Alabama, Hawaii, Mississippi, New Mexico, South Carolina and West Virginia), but the lowest birthrates were not concentrated in any particular area (Alaska, Hawaii, New Mexico, New York, Washington and West Virginia).

The highest abortion rates for black teenagers were in New Jersey and New York, which may help to explain why birthrates in those states were low or average. The lowest abortion rates were in the South and West (Alabama, Arkansas, Mississippi, New Mexico, South Carolina and Texas).

Many southern states that had high overall teenage pregnancy and abortion rates were close to the national rates for black and white teenagers examined separately. Pregnancy rates of white teenagers in the South tended to be close to the national rate, birthrates slightly above it and abortion rates well below it. Among black teenagers, pregnancy and abortion rates were usually below, and birthrates close to, the national rates for blacks. The fact that black teenagers represent a higher proportion of the population in the South than in other regions explains the high overall rates in these states.

Little geographic consistency is evident in Hispanic teenagers' rates of pregnancies, births and abortions, except that the states with the four lowest pregnancy rates (Arkansas, Mississippi, South Carolina and Tennessee) and birthrates (Kentucky, Louisiana, Maryland and Mississippi) were all in the South. The highest abortion rates were in New Jersey and New York.

Discussion

Three factors can contribute to shifts in birthrates and abortion rates: changes in intended pregnancy rates, in unintended pregnancy rates and in the proportion of unintended pregnancies that are resolved by abortion. Since only 15% of pregnancies among teenagers are intended,12 however, the desire to have children presumably is a minor factor in explaining teenage pregnancy. Nevertheless, changes in the level of motivation to prevent childbearing could affect pregnancy rates and decisions about pregnancy resolution. The most important factors are probably the rate of unintended pregnancy (which is a function of contraceptive use and the level of sexual activity) and the decision between abortion and childbearing when an unintended pregnancy occurs (which is affected by the accessibility of abortion services, attitudes toward abortion, the level of motivation to avoid childbearing and other factors).

The sharp increase in the birthrate of teenagers between 1987 and 1991 has never been fully explained. Reduced use of abortion appears to account for only about one-third of the change, since the abortion rate declined by four abortions per 1,000 teenagers, while the birthrate increased by 12 births per 1,000. Rising opposition to abortion among teenagers may have resulted in less use, although no data are available to demonstrate a change in attitude, and public opinion about the legality of abortion has changed little or become more favorable over time.13

Greater acceptance of childbearing outside marriage could have been a factor, as could reduced availability of abortion services.14 New parental consent or notification laws probably had at most a very small effect: Between the beginning of 1986 and the beginning of 1991, six states (Alabama, Arkansas, Maine, Ohio, South Carolina and Wyoming) implemented new parental involvement laws, but these states contain only 10% of all women aged 15-19.

It is even more difficult to explain the increased pregnancy rate, but factors such as a rising proportion of teenagers living in poverty and the immigration of Hispanics from high-fertility cultures may have played a role. Also, the effectiveness of contraceptive use may have declined if there was a shift from pill to condom use in response to messages on how to prevent infection with the human immunodeficiency virus (HIV).

Between 1991 and 1995, the birthrate of black teenagers dropped a surprising 17%, to a historically low level. (The fertility of black women in their 20s also fell, by a slightly smaller percentage. 15) We cannot yet say exactly what role abortion played in this decline, but preliminary data suggest that abortion rates were decreasing, so unintended pregnancy probably decreased substantially among black teenagers; this would also explain the drop in the abortion rate between 1991 and 1992.

The CDC's Youth Risk Behavior Survey found that between 1991 and 1995, the proportion of non-Hispanic black high school students who had used a condom at last intercourse increased from 48% to 66%, with no offsetting decline in pill use.16 The availability of the contraceptive implant and injectable, which are long-acting and highly effective, may also have contributed to a decline in unintended pregnancy. The proportion of black women aged 15-19 who were sexually experienced did not change significantly during the period. 17

The increase in condom use may reflect more favorable attitudes toward condoms resulting from concern about HIV infection. Among the signs and causes of such a change in the 1990s are awareness that well-known sports figures have contracted HIV through heterosexual intercourse, positive references to condom use in rap songs and music videos, and condom commercials on television. The experiences of black sports figures and rap musicians may have particular impact in the black community. Other possible influences may be sexuality education and other efforts emphasizing HIV prevention.

Between 1991 and 1994, the birthrate among non-Hispanic white teenagers fell by 7%; it probably continued to fall in 1995. This group may have been affected by some of the same influences as black teenagers, but not as powerfully. The Youth Risk Behavior Survey found that the proportion of white teenagers who had used a condom at last intercourse increased from 47% in 1991 to 53% in 1995, a smaller rise than was seen among blacks. 18 In addition, the 1995 National Survey of Family Growth found that the proportion of white non-Hispanic female teenagers who had ever had intercourse dropped from 52% in 1988 to 50% in 1995.19

In contrast to the other subgroups, Hispanic teenagers experienced a distinct increase in rates of pregnancies, births and abortions between 1990 and 1992; in 1995, their birthrate was 11% higher than that of blacks. The reasons are unclear. One possible factor is a deterioration of traditional cultural norms among recent immigrants, which may be reflected in the increase in the proportion of Hispanic young women aged 15-19 who had ever had intercourse—from 49% in 1988 to 55% in 1995. 20 New attitudes toward condom use may not have been incorporated into Hispanic culture yet, and teenagers may have been exposed to different media messages from those in the black and non-Hispanic white communities.

Distinct regional patterns are evident in teenage reproductive behavior. Pregnancy rates and birthrates are generally higher in the South and West than in the Northeast and Midwest. Abortion rates are highest in three Pacific states (California, Hawaii and Washington), Nevada, a contiguous group of states in the East (New York, New Jersey, Delaware and Maryland) and Florida. Highly urban states tend to have higher abortion rates than rural states.

The changes from 1988 to 1992 show few regional patterns. Pregnancy and abortion rates fell in all the New England states except Rhode Island; otherwise, changes in rates of births, abortions and pregnancies were distributed evenly around the country. Although an increase in births appears to have been associated with a decrease in abortions in some states, changes in pregnancy rates caused rises or falls in both births and abortions in others.

State variations in pregnancy rates and birthrates are very different for white and black teenagers. Surprisingly, for the 29 states with data, there is a negative correlation between the pregnancy rates of these two groups (r=-.59, p<.05) and a small and nonsignificant negative correlation for birthrates. For example, in Minnesota and Wisconsin, black teenagers have very high pregnancy rates and birthrates, while white teenagers have among the lowest rates in the country. In New Mexico and Texas, on the other hand, rates are low or average for black teenagers and are above average for whites. With respect to rates of pregnancies and births, correlations are also low between Hispanic and white teenagers and between Hispanic and black teenagers.

One implication of these findings is that state policies and other state characteristics either have little influence on teenage pregnancy rates and birthrates or exert different influences on black and white teenagers. For example, if differences in state sexuality education or public assistance policies affect pregnancy, the effects either are small or are different for white and black adolescents.

Abortion rates, on the other hand, have a marginally significant positive correlation for white and black teenagers (r=.35, p<.10). A possible explanation is that the availability of abortion services affects the ability of adolescents of both races to terminate unintended pregnancies. This factor, or other common influences, may also be affecting Hispanic teenagers, whose abortion rate is highly correlated with that of both whites (r=.62) and blacks (r=.81).

Overall trends in recent years have been toward lower rates of pregnancies, births and abortions, but more research is needed to understand the reasons, which may differ by race and ethnicity. Research is also needed on the impact of state policies affecting minors and teenagers, and on the factors that influence a majority of pregnant teenagers in some states to end their pregnancies and in others to carry them to term.

The incompleteness of the abortion data, however, limits the research that can be done and the conclusions that can be drawn. In this study, the abortion rates of minors in many states may be inaccurate because information is lacking on the number of minors who obtain abortions outside their state of residence. Our assumption that teenagers obtain abortions out of state at the same rate as do older women is unjustified where parental involvement requirements or other policies might give teenagers an incentive to seek abortions in other states. Some states have data exchange agreements that provide them with information on their residents who obtain abortions in other states, but the data may still be incomplete if reporting in neighboring states is incomplete. Thus, improved abortion reporting systems would yield important benefits.