Demographics of Adolescent Sexual Behavior, Contraception, Pregnancy, and STDs
Newcomer, Susan, Baldwin, Wendy, Journal of School Health
Women younger than age 20 have been having babies for thousands of years. In the U.S. in 1967, 120 of every 1,000 women ages 18-19 had a baby each year. In 1988, the birth rate was 82/1,000 for women ages 18-19. While never high, birth rates for women age 16 and younger have not declined at the same pace as rates for older adolescents. Figure 1 contains age-specific birth rates for teen-agers from 1920-1987.
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What has increased dramatically over this time, however, is the proportion of births to young women outside marriage. In 1960, 15% of births to adolescents were out-of-wedlock; in 1988, 66% were to unmarried women (Figure 2). Underlying the data on adolescent births is the more complex picture of adolescent sexual activity and contraceptive use. Demographics of the fertility-related behaviors of youth ages 10-18 are described.
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DATA AND DATA COLLECTION
Knowing where and how data are collected allows for critical examination of data quality. To assess the demographics of fertility-related behavior, the best and most reliable data are the numbers of births to women of each age. For this review, data examined comes from U.S. vital statistics.
States collect information on birth certificates from hospitals, physicians, and midwives, a process which can take a year. However, the process allows county-by-county comparisons of mothers on a few variables such as birthweight, mother's age and education, and for some states, marital status and father's age and education. To obtain birth rates, or proportions of women who become mothers in a given year, the number of women "at risk" of becoming mothers must be known, a number which changes yearly. This information is based on numbers from the decennial U.S. census, with estimates for the nine years between censuses. Estimates for small areas such as counties, especially for the years at the end of the decade, may not be accurate because people may have moved in or out of the area. Thus birth rates for years between censuses for small areas may not be precise.
Information on the number of pregnancies, the sum of births plus miscarriages, stillbirths, and abortions, is more difficult to obtain. No national reporting requirement exists for abortions or miscarriages, though some states collect the information. However, the Centers for Disease Control conducts surveillance on abortions in all 50 states and the District of Columbia, providing basic characteristics of women who undergo abortions. In many years, the Alan Guttmacher Institute has surveyed abortion providers. From these two data sources, the number of abortions obtained by teen-agers nationwide can be estimated, though obtaining data for states or smaller areas cannot be done precisely. Overall pregnancy rates are calculated in this method, since individual reporting of abortions in sample surveys is so incomplete that the numbers are severely limited in their usefulness. Data on miscarriages and stillbirths also are difficult to obtain, so estimates of pregnancy rates simply reflect an inflation of births and abortions to account for the likely number of miscarriages. In addition, birth rates based on all teen-agers will be lower than birth rates based on the number of teen-agers having sexual intercourse, since not all teen-agers are "at risk" of pregnancy.
National household sample surveys of young men and women provide information on contraceptive use, sexual behavior, and numbers and types of sexual partners. The data actually may be more comprehensive for adolescents than for adults. Three national surveys of the sexual and contraceptive behavior of youth have been conducted; young women were surveyed in 1971 and 1976, and young men and women living in metropolitan areas were interviewed in 1979. The National Survey of Family Growth began to include young unmarried women in regular surveys in 1982. …