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Objective. —To analyze pregnancy, abortion, and birth rates among US adolescent girls in 1980, 1985, and 1990. Design. —Retrospective analysis of trends in data on pregnancies, abortions, and births. Population. —US adolescent girls aged 13 to 19 years. Main Outcome Measures. —Pregnancy, abortion, and birth rates (with and without adjustment for sexual experience) among teenaged girls aged 15 to 19 years and girls under 15 years. Results. —Although pregnancy rates among all teenaged girls 15 to 19 years old remained fairly stable from 1980 to 1985, they increased by 9% during the last half of the decade, totaling 95.9 pregnancies per 1000 teenaged girls 15 to 19 years old by 1990. Because rates of sexual experience increased even faster, pregnancy rates among sexually experienced teens aged 15 to 19 actually declined between 1980 and 1990 by approximately 8%. Abortion rates among these teens remained stable during the 1980s, with 35.8 and 36.0 abortions per 1000 in 1980 and 1990, respectively. As with overall pregnancy rates, abortion rates among these sexually experienced teenaged girls declined during the 1980s. Between 1980 and 1985, birth rates among teenaged girls aged 15 to 19 years declined by 4%, but they increased by 18% during the latter half of the decade, totaling 59.9 births per 1000 in 1990. Among these sexually experienced teenagers, birth rates also declined between 1980 and 1985 and then increased over the next 5 years. In 1990, pregnancies and abortions among girls younger than 15 years accounted for only 3% of all adolescent pregnancies and abortions. However, the number of births among these younger adolescents increased by 15% over the decade. In that age group, trends in pregnancy, abortion, and birth rates over the decade were similar to those for older teens. However, during the late 1980s, the abortion rate declined and the pregnancy rate remained stable, resulting in a 26% increase in the birth rate. Conclusions. —Despite efforts to reduce adolescent pregnancy in the United States, pregnancy and birth rates for that group continue to be the highest among developed countries. Considering that 95% of adolescent pregnancies are unintended, increased efforts to prevent these pregnancies are warranted. ( JAMA . 1996;275:989-994)

Data on the risk of death associated with various contraceptive methods are incomplete. Therefore, we analyzed the mortality rates for young, black inner-city women who used one of four methods of contraception—oral contraceptives, depomedroxyprogesterone acetate, intrauterine (contraceptive) devices, and barrier methods. The subjects were 30,580 15-to 44-year-old women who enrolled at a family planning clinic between 1967 and 1972 and who were observed by monitoring death certificates through the end of 1977. Forty percent of the 218 deaths observed were from accidents and violence. Use of this family planning clinic greatly reduced the risk of death from childbearing; only two deaths were associated with pregnancy and childbirth, compared with the 24 deaths expected. Overall, users of the four methods died at similar, low rates. Given that this study involves considerable loss to follow-up, possible acute effects of contraceptives (eg, infections or thrombosis) are more accurately estimated than possible long-term effects (eg, cancer). ( JAMA 1984;251:1044-1048)

We studied the association between estrogen replacement therapy (ERT) and the risk of breast cancer as part of the Cancer and Steroid Hormone Study. All subjects in the analysis were postmenopausal women enrolled from eight geographic areas. Women 25 to 54 years old with newly diagnosed breast cancer were identified through population-based tumor registries and diagnosed between Dec 1,1980, and Dec 31,1982. Controls were selected from the same eight geographic areas by the random digit dialing of residential telephone numbers. Analyses included 1369 cases and 1645 controls. Among women with bilateral oophorectomy, the relative risk of breast cancer for women who had ever used ERT was 1.3, compared with women who had never used ERT. Among women who had undergone hysterectomy but who still had at least one ovary, the relative risk was 1.1; among women who reported a natural menopause, the relative risk was 0.8. Overall, the risk of breast cancer did not appear to increase appreciably with increasing ERT duration or latency, even for durations and latencies of 20 years or longer. ( JAMA 1987;257:209-215)

In Reply.— Drs Lemon and Foley incorrectly cite the data from our report and overstate our conclusions; however, we agree with their recommendation that further research is needed to clarify the risk of breast cancer among women who have used estrogen replacement therapy (ERT). First of all, the total numbers of cases and controls included in our analysis were 1369 and 1645, respectively, not 942 and 1117 as cited by the authors. Second, 56 cases and 81 controls used ERT for at least ten years; 114 cases and 154 controls first used ERT at least ten years ago. Finally, in our report, because of the widespread use of ERT 1 and the inconsistencies and limitations of available data (including our report), we urged further study of the effects of long-term and high-dosage use and emphasized the importance of identifying subgroups of women who may be at increased risk of breast

To investigate whether a family history of breast cancer increases a woman's risk of developing breast cancer, we analyzed data from the Centers for Disease Control's Cancer and Steroid Hormone Study. The 4,735 cases were women 20 to 54 years old with a first diagnosis of breast cancer ascertained from eight population-based cancer registries; the 4,688 controls were women selected at random from the general population of these eight areas. Compared with women without a family history of breast cancer, women who had an affected first-degree relative had a relative risk of 2.3; women with an affected second-degree relative had a relative risk of 1.5; and women with both an affected mother and sister had a relative risk of 14. The risk of breast cancer for a woman was higher if her first-degree relative had unilateral rather than bilateral breast cancer or had breast cancer detected at a younger rather than older age. For women aged 20 to 39, 40 to 44, and 45 to 54 years, the estimated annual incidence of breast cancer per 100,000 women attributable to a first-degree family history of breast cancer was 51.9, 115.1, and 138.6, respectively, and that attributable to a second-degree family history of breast cancer was 12.1, 19.2, and 92.4, respectively. ( JAMA 1985;253:1908-1913)

In Reply.— Dr Maxey has raised the issue of whether the results of the recently published study of endometrial cancer and oral contraceptives could possibly be biased because one needs a telephone to be selected as a control. He was concerned that women of upper socioeconomic status would be more apt to have telephones and also more apt to use oral contraceptives than those of lower socioeconomic status. If this were true, it would cause a spuriously high estimate of oral contraceptive use in our control group relative to our cases— cases being ascertained from hospital logs and therefore not needing telephones to enter the study. We were concerned about this possible bias and asked cases whether they had a telephone. In fact, 186 of the 187 cases had telephones. Thus, our method of selecting controls by telephone could not have biased the study in the way that Dr Maxey