Oregon Vital Statistics Annual Report 1995, Volume 1
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There were 8,283 pregnancies to Oregon females under 20 years of age in 1995. In 60 percent of these cases, the person had not yet completed high school nor obtained a general equivalency diploma (GED). Of those who took their pregnancy to term, 74.3 percent were unmarried at the time of birth.
To aid understanding of teen pregnancy trends, this report bases its analysis on two separate age groups: females under 18 and females 18-19. These groups are then compared to women age 20 and above and to each other. The number of pregnancies is determined by adding the numbers of births and abortions reported for residents. Because some neighboring states (e.g., California) do not exchange abortion reports with Oregon, those who obtain an out of state abortion are not always included in this count.
Efforts at preventing teen pregnancies are focused primarily on females under age 18. In 1995, the pregnancy rate among 10- to 17-year-olds increased to 19.2 per 1,000, from 18.9 in 1994
(see sidebar). The current rate is 1.3 times greater than the Oregon Benchmark goal for the year 2000 of fifteen pregnancies per 1,000 females. If the Benchmark goal is to be achieved, the rate must decrease by 4.4 percent per year.
During 1995, at least 3,284 pregnancies occurred among Oregon females under 18 years old. This 70-case increase over the previous year is not statistically significant, however.
While the abortion rate remained the same, the birth rate increased, indicating that sexually active younger teens showed no improvement in protecting themselves against becoming pregnant compared to 1994.
The youngest teen to become pregnant was 12 when she gave birth; 191 of the teen pregnancies reported in 1995 involved teens under 15. The number of pregnancies among such young teens was higher than in 1994 by 8 cases.
In 1995, the pregnancy rate of female Oregonians age 18-19 increased to 120.3 per 1,000, a 1.4 percent increase from 1994. Comparisons with the 1994 figures show increases of less than one percent in the birth rate and 3.1 percent in the abortion rate reported among 18- to 19-year-olds.
[Table 4-1a and
In 1995, while the number of abortions increased slightly among Oregon teens age 10-17, the abortion rate remained unchanged due to a proportional increase in the population.
[Figure 4-3]. The number of abortions to those age 15-17 decreased by 0.9 percent and the number for teens under the age of fifteen increased by nearly 32 percent from 1994. The abortion rate of 18-19 year-olds increased by 3.1 percent.
[Table 4-1a &
Figure 4-4 presents the historical pattern of pregnancy resulting in birth instead of abortion. As the graph indicates, teens were less likely to carry a pregnancy to term than were women in their middle childbearing years.
Historically, (since 1980) the younger the teen the more likely the pregnancy would be terminated. Those 15-17 years-old were more likely to obtain an abortion compared to both the older and very young teens.
Pregnancies among all teens were more likely to result in a birth than an abortion. Although teens under 15 years were nearly as likely as those age 15-17 to take a pregnancy to term in 1994, the differential which has historically characterized the youngest teens reappeared in 1995.
There were 1,203 abortions to Oregonians age 10-17 reported during 1995, a 0.9 percent increase from 1994.
[Table 4-2]. The abortion rate for this group remained the same at 7.0 per 1,000 females. When compared to the record high of 1980, however, the abortion rate of young teens has dropped to nearly one-half of its previous level.
Among 18- to 19-year-olds, the rate of reported abortions increased by 3.1 percent in 1995, to 37.0 per 1,000 females.
[Table 4-1a and
4-1b]. This is 36 percent below the record high of 1980. Because most abortions represent mistimed or unwanted pregnancies, these figures indicate that a sizeable population of teens continue to engage in unprotected sex.
In 1995 there were 2,081 births to Oregon teens under 18 years of age. In 8.5 percent of these cases, it was the mother's second or third child.
[Table 4-9]. Sixty-three percent of pregnancies among females under 18 resulted in a live birth during 1995, compared to 46 percent in 1980.
While the pregnancy rate for 10- to 17-year-olds has decreased by 22 percent since 1980, their birth rate, a measure of premature parenthood, has increased by 8.0 percent since 1980.
[Table 4-2]. In fact, gains made during the mid-1980s have disappeared and the birth rate among those of high school age (15-17) increased 15 percent above the 1980 rate.
[Table 4-1a and
The number of births to older teens (age 18-19) totalled 3,460, an increase of 127 from the previous year. Their birth rate was 83.3 per 1,000 females, a slight increase from 1994.
[Table 4-1a and
4-1b]. Sixty-nine percent of pregnancies reported among this group resulted in a live birth, compared to 59 percent in 1980.
The birth rate among 15- to 19-year-olds (commonly used in historical and national comparisons) increased slightly from the 1994 rate (51.3 vs. 52.2 per 1,000 females).
[Table 4-1a &
4-1b]. Although the rate increased slightly, it was 5.4 percent below the all-time high of 55.2 per 1,000 in 1991.
Comparison of birth rates available for 15-19 year old teens shows that Oregon's rate was 8.3 percent below the national rate (52.2 vs. 56.9 per 1,000 females)
1 This favorable teen birth rate may be attributed in large part to Oregon's demographic characteristics. Racial and ethnic subpopulations that display especially high teen birth rates such as African Americans and Hispanics are under-represented in the state. (For further discussion of Oregon's demographic characteristics and teen pregnancy rates, see the
Methodology Section of Appendix B).
Prenatal care should begin within the first three months of pregnancy to allow early detection of complications and to ensure the health of both mother and infant. An Oregon Benchmark goal stipulates that by the year 2000, 90 percent of females, regardless of age, begin medical care during the first trimester of pregnancy. Only 81.2 percent of Oregon women age 20 or older who gave birth in 1995 met this standard. Of all teens who gave birth in 1995, 62.6 percent started prenatal care during the first trimester, nearly unchanged from 1994
(see sidebar). Nearly fifty-nine percent of those under 18 received early prenatal care.
Other demographic factors such as race, ethnicity and marital status combine with age to influence the likelihood of a teenager receiving early prenatal care. In 1995, for example, only 49.8 percent of unmarried Hispanics age 15-17 (all races) started prenatal care during their first trimester, compared to 70.6 percent of older non-Hispanic white teens who were married at the time of their child's birth.
"Inadequate prenatal care" has been defined as care that begins after the second trimester of pregnancy, or that involves fewer than five medical visits. By this measure, 11 percent of 15- to 17-year-old teens and 9.9 percent of older teens did not receive adequate prenatal care in 1995.
[Table 4-4]. By comparison, 5.2 percent of women 20 years or older received inadequate care.
[Table 4-10]. The proportion of mothers under 20 who received inadequate prenatal care changed only slightly from 1994.
The proportion of teens age 15-17 who begin prenatal care during the third trimester increased for the first time in four years to 69.7 per 1,000 live births; additionally, teens are more likely to begin such care late in pregnancy than women age 20 and older.
[Figure 4-6]. Teens remained about twice as likely as women 20 and older to go through pregnancy without a single visit to a medical provider. In 1995, the rate of "no prenatal care" among teens under age 18 was greater than that of older teens (15.9 vs. 11.9).
[Figure 4-7] The difference between the rates is not statistically significant, however. The rates for teens 15-19 increased between 1994 and 1995 while the rate for women age 20 and older decreased slightly.
Whether reflecting premature delivery or small size for gestational age, the low birthweight (LBW) rate (< 2,500 grams) represents the single best measure of health for newborn infants. Changes in the LBW rate of a group may indicate aggregate changes in the mother's personal behavior during pregnancy or other conditions that affect fetal health—such as better nutrition or access to prenatal care.
In 1995, the low birthweight rate for teen mothers age 15-19 was 69.2 per 1,000 births
[Table 4-4], a 4.1 percent increase from 1994. For 15- to 17- year-olds, the rate increased 7 percent. The rate remained higher than the LBW rate for mothers age 20 or older.
[Table 4-9]. A persistent LBW differential between age groups indicates that the babies of teenage mothers are at elevated risk.
The relationship between level of prenatal care and frequency of low birthweight infants among teen mothers is shown in Table 4-3. In general, teen women who did not receive adequate prenatal care in 1995 were over twice as likely to have low birthweight babies as those who had received adequate care.
[Figure 4-9]. This parallels findings based on analysis of births to mothers of all ages.
The low birthweight rates among teen mothers by racial/ethnic categories are displayed in the sidebar. The rate for the Hispanic teens (all races) category increased for both younger and older teens. Among non-Hispanic, non-white groups, the low birthweight rate for older teens decreased while the rate for the younger teens increased substantially
The Apgar score recorded by the birth attendant five minutes after birth provides a second measure of infant health at the time of delivery. A score of less than seven is considered low and indicates that the infant is at greater than normal risk for morbidity and mortality. The 1995 rate of low Apgar scores among newborns of teen mothers was 17.6 per 1,000 births
[Table 4-9], a 19 percent decrease from the 1994 rate of 21.8. The 1995 rate was 21 percent higher than that for mothers 20 years or older (14.6).
Estimates of tobacco and alcohol use during pregnancy are presumed to be minimum counts due to under-reporting on birth certificates. Also, reports of substance use may be biased in terms of expectations of behavior related to personal characteristics of the mother, such as race, ethnicity, or economic level.
Table 4-9 shows that teenage females (age 15-19) were less likely to report use of alcohol during pregnancy than older women (21.0 vs. 26.2 per 1,000 births). Reported alcohol use declined slightly for both age groups during 1995.
Teens (15-19) were more likely than older women to report smoking during pregnancy (27.3% vs. 16.5%).
[Table 4-9]. Mothers who smoked during pregnancy were more likely to have low birthweight babies than nonsmokers (see sidebar). Although this difference was more pronounced among mothers 20 or more years of age, it remains one of the most important preventable causes of low birthweight infants for teen mothers as well.
Logistic regression analysis revealed that, even after accounting for the effects of other variables, the likelihood of a low birthweight baby among teenaged mothers who smoked during pregnancy was 1.55 times greater than among those who did not. This fact, coupled with the proportion of teen mothers who were smokers, indicates that 13 percent of low birthweight births among teenaged mothers may be attributed to use of tobacco during pregnancy. Based on this, if pregnant teens had not smoked, there could have been 50 fewer babies born with a low birthweight in 1995.
Births to teen mothers are more than twice as likely to be paid for with public funds as are births to older women. In 1995, at least 61 percent of births to teens (< 20) were paid for primarily by public insurance, compared to 30 percent for mothers age 20 and older [Table 4-10]—an indication of the continuing, disproportionate effect of teen pregnancy on the state's Medicaid budget. While the 1995 figure remained the same for women age 20 and older, the percentage for teens under age 20 decreased by 9.0 percent. No significant difference was apparent in 1995 between the source of payment for younger teens and older teens (64% vs. 65%).
During 1991-1995, a large percentage of teen mothers did not report information regarding the age of the father on the birth certificate. Among teen mothers under age 15, 73 percent did not report father's age. Based on birth certificate information, however, 8.6 percent of the fathers were under the age of 18 and 18.2 percent were 18 or older. Among teen mothers age 15-17, half did not report the age of the father. Still, at least 7.3 percent of the fathers were under age 18, and 42.9 percent were 18 years or older.
[Figure 4-10 &
Figure 4-10 displays the age differential between teen mother's ages and known ages of fathers for the time period 1991-1995.
- Rosenberg HM, Ventura SJ, Maurer JD, et al. Births and Deaths; United States 1995. Monthly Vital Statistics Report; vol 45 No 3, supp 2. Hyattsville, Maryland: National Center for Health Statistics. 1996.