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Obstetrics & Gynecology:
doi: 10.1097/AOG.0b013e3181a99ddd
Original Research

Adolescent Sexual Behavior During Periods of Increase and Decrease in the Abortion Rate

Falah-Hassani, Kobra MSc1; Kosunen, Elise MD PhD2; Shiri, Rahman MD PhD1; Jokela, Jukka MSc3; Liinamo, Arja PhD4; Rimpelä, Arja MD, PhD1

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From the 1Tampere School of Public Health and the 2Medical School, University of Tampere, Tampere, Finland; the 3Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland; and the 4Department of Health Care, Helsinki Metropolia University of Applied Sciences, Helsinki, Finland.

Supported by the Ministry of Social Affairs and Health (Helsinki, Finland).

Corresponding author: Kobra Falah-Hassani, Tampere School of Public Health, FIN-33014 University of Tampere, Tampere, Finland; e-mail:

Financial Disclosure Mr. Falah-Hassani received a grant from the Finnish Centre for International Mobility and the Doctoral Programs in Public Health. Mr. Falah-Hassini and Dr. Rimpelä received grants from the Competitive Research Funding of the Pirkanmaa Hospital District, Tampere University Hospital. The other authors did not report any potential conflicts of interest.

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OBJECTIVE: To study changes in adolescent sexual behavior in periods of increase (1994–2000) and decrease (2001–2007) in the abortion rate.

METHODS: School surveys with self-administered questionnaires were carried out annually among eighth graders (mean age 14.8 years) and ninth graders (mean age 15.8 years) (N=286,665) in 1996/1997 and 2006/2007. Schools participated biennially. The proportions of respondents reporting noncoital (kissing, light petting, heavy petting) and coital (ever had sexual intercourse, intercourse at least 10 times, at least three partners) sexual experience and nonuse of contraception were studied.

RESULTS: Among adolescents, both coital and noncoital sexual experiences and the proportion of those not using contraception increased between 1996–1997 and 2000–2001 (P for trend <.01, all) and decreased from 2000–2001 onward (P<.001, all), except the proportion of at least 10 coital events, which did not decrease. Among sexually experienced adolescents, a similar increase in coital experiences (intercourse at least 10 times from 38.2% to 41.5%, at least three partners from 27.8% to 30.7%, P<.001) and in not using contraception (from 17.2% to 19.1%, P=.002) was seen before 2000–2001, but after that the only significant change was a further increase in the proportion of those reporting intercourse at least 10 times (from 41.5% to 47.8%, P<.001).

CONCLUSION: The proportion of adolescents reporting noncoital sexual experiences, intercourse, or not using contraception increased in the 1990s and decreased in the 2000s, reflecting the changes in the abortion rate. However, as the abortion rate decreased, the intensity of sexual activity further increased among sexually experienced adolescents, suggesting that the fall in the abortion rate may be due to contraception and more effective sexual education.


The abortion rate in Finland was among the lowest in Europe1 after a long and steady decline in the 1980s and early 1990s. However, between 1994 and 2000, the abortion rate among girls age 15–17 years increased from 7.4/1,000 to 12.3/1,000 (66%) (Fig. 1).2 Since 2000, teenage abortion statistics again have shown a downturn; birth rates have remained steady (Fig. 1). These changes were specific to the age group. Among 20-year-olds to 24-year-olds, the abortion rate increased slightly and continued to do so until 2007; in older age groups the abortion rate remained steady.3

Fig. 1
Fig. 1
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The changes in abortion rates among adolescents indicate changes in their sexual behavior but also may indicate a decline in choosing abortion. So far, little is known about the changes in sexual behavior reflected in increased abortion and pregnancy rates among adolescents. Although most 15-year-olds to 17-year-olds have not yet experienced sexual intercourse, a larger proportion of teenagers engaged in sexual activity could explain the increased abortion rate. On the other hand, even if the proportion of teenagers who are sexually active does not increase, teenagers may engage in more frequent intercourse, use contraceptives less effectively, or have more sexual partners, thus increasing the risk of pregnancy.

The aim of this article is to study changes in the sexual behavior of Finnish adolescents from 1996 to 2007 using two time periods. The first period (from 1996 to 2000) is characterized by a higher abortion rate and the second period (from 2000 to 2007) by a lower abortion rate. Data on sexual behavior were available for the age group of 14 to 16 years (Fig. 2).

Fig. 2
Fig. 2
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The School Health Promotion Study is an anonymous survey that has been carried out annually in Finland since 1996. The survey elicits adolescents' living conditions, school experiences, health, health behavior, health knowledge, and experiences of student welfare services. The data were collected in the provinces of Southern Finland, Eastern Finland, and Lapland in even-numbered years and in the provinces of Western Finland and Oulu in odd-numbered years.4 Hence, the collected data in two consecutive years cover the whole country. The study was approved by the ethics committee of Tampere University Hospital.

Schools' participation was voluntary. Their number increased during the study period, but the data here were derived only from those schools participating in every survey since 1996/1997. There were only minor differences in sexual behavior between the schools joining the study in 1996/1997 and those joining later. Slightly less sexual intercourse was reported by adolescents from the schools that joined the study at the beginning (22.5%) than by adolescents from the schools joining the study later (23.4%). The difference was found only from 2002 onward.

Eighth and ninth graders completed the questionnaire during an ordinary school lesson under the supervision of their teachers. Student participation was voluntary, but virtually all chose to participate. To emphasize the confidentiality of the study, all completed questionnaires were sealed in an envelope addressed to the research group. Pupils who were absent on the survey day (on average 5–10%) were not contacted. In the eighth grade, the mean age was 14.8 years (standard deviation±0.3 years), and in the 9th grade it was 15.8 years (standard deviation±0.3 years). The biennial numbers of participants are presented in Table 1. Participants totalled 296,453, of whom 9,788 were excluded owing to missing information on sexual activity. In all, the analysis included 286,665 adolescents (143,843 boys and 142,822 girls).

Table 1
Table 1
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Sexual experiences were investigated by asking whether the respondent had ever experienced kissing on the mouth, light petting (fondling on top of clothes), heavy petting (fondling under clothes or naked), and sexual intercourse. The response choices for each item were yes and no. The first three items described noncoital behaviors. Adolescents who had experienced sexual intercourse were asked to provide data on the intensity of their sexual activity: “How many times have you had intercourse?” (response choices once, 2–4 times, 5–9 times, 10 times or more); “How many sexual partners have you had altogether?” (one, two, three or four, five or more); and “Which contraceptive method did you use in your most recent intercourse?” (none, condom, oral contraceptives, condom and oral contraceptives, other methods). The prevalence of other methods ranged from 0.2% to 0.4% in the total population and from 1% to 1.6% in sexually active adolescents. Because the responses in the category “other methods” generally included only methods of natural family planning (withdrawal, calendar method), which do not provide reliable contraception, this category together with the option “none” were reclassified as “no contraception.”

Tests for trend (linearity) were conducted with logistic regression by including the survey year as a continuous variable in the models and a binary sexual behavior variable as an outcome. We used a logistic regression model with the cluster option. We used the schools as the cluster variable and adjusted the standard errors and P-values for trends for the clusters. For proportions, 95% confidence intervals were calculated. We used Stata 10 software (Stata Corporation, College Station, TX) to analyze the data.

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All measures of noncoital sexual experiences showed an increase between 1996/1997 and 2000/2001 and thereafter a decrease (Table 1). The measures of sexual activity and its intensity followed the same pattern. The proportion of adolescents reporting experience of sexual intercourse increased from 20.5% to 24.9% between 1996/1997 and 2000/2001 (Fig. 1, Table 1). In parallel the proportion of those reporting sexual intercourse at least 10 times increased from 7.7% to 10.2%, at least three sex partners from 5.7% to 7.6%, and nonuse of contraception from 3.5% to 4.7%. The measures of intensity of sexual activity decreased between 2000/2001 and 2006/2007. The only exception was the proportion of those reporting sexual intercourse at least 10 times, which did not decrease between 2000/2001 (10.2%) and 2006/2007 (10.0%) (Table 1).

The results were similar for both sexes between 1996/1997 and 2000/2001 (Table 1), with the exception of kissing on the mouth, which did not increase in girls. In the period 2000/2001–2006/2007, there were small sex differences in the measures of intensity of sexual activity. In boys, the proportion of those reporting sexual intercourse at least 10 times, at least three partners, or nonuse of contraceptives decreased between 2000/2001 and 2004/2005 (P for trend <.001, all), but in 2006/2007, the proportions returned to the level of 2000/2001; in girls the decrease continued throughout the period.

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Changes in the Total Population

Between 1996/1997 and 2000/2001, the intensity of sexual activity increased significantly among those who had already experienced sexual intercourse, measured by reporting sexual intercourse at least 10 times (from 38.2% to 41.5%) and by reporting at least three partners (from 27.8% to 30.7%). Correspondingly, the proportion of those reporting no contraception at last intercourse increased significantly from 17.2% to 19.1% (Table 2). In the sex-specific analysis, the trends were statistically significant in both sexes (Table 2).

Table 2
Table 2
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During the period 2000/2001–2006/2007, the proportion of adolescents reporting sexual intercourse at least 10 times continued to increase (from 41.5% to 47.8%) (Table 2). The proportions of those reporting at least three sexual partners (from 30.7% to 30.3%), or no contraception at last intercourse (from 19.1% to 18.6%) did not change. The results were similar for both sexes.

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A shift to an earlier age of starting sexual activity was observed in the 1990s, when the proportion of teenagers reportedly engaged in sexual activities increased. At the same time, the use of effective contraception decreased, and, on average, the adolescent population had more partners and more coital events. In light of these results, the increase in the abortion rate is no surprise.

The years 2001–2002 were a turning point for the decline in the number of adolescents with sexual experience and those who had not used effective contraception. As could be expected, this was reflected in a declining abortion rate. However, contrary to expectations, the number of coital events in the total population, when measured by the proportion of those reporting sexual intercourse at least 10 times, remained steady. Furthermore, the sexual activity of those reporting intercourse was more intense when measured by the above-mentioned number of coital events. Further studies are needed to understand this development.

By comparison, younger age at first sexual intercourse in the 1990s also has been observed and studied in other Western countries: the United Kingdom,5–8 Denmark,9 France,5,6 Latvia,5,6 and the United States.10 The more explicit treatment of sexual matters in the media, advertisements, and fashion, called overeroticization or hypersexualization,11 throughout the Western world is likely to have aroused more interest in sexual experiences12,13 and contributed to earlier sexual activity. Moreover, the greater number of partners probably reflects the same phenomenon, as does the increase in noncoital sexual experiences. Although this phenomenon contributed to the increase in the 1990s, it is common knowledge that expression of overt sexuality in the media has not diminished in the 2000s.

Decrease in sexual experiences at an early age starting in the first years of the new millennium has not been reported in other countries, thus it is not possible to conclude whether this is a country-specific phenomenon or whether a similar trend can be detected in other Western countries. Some of the explanatory factors are most likely country-specific for both periods.

The greater number of adolescents reporting no contraception in the 1990s may reflect difficulties in easy access to products. In an earlier study, we reported diminishing use of oral contraceptives among Finnish girls at the end of the 1990s.14 The use of oral contraceptives can be considered an indicator of the access to family planning services. In the 1990s, as a consequence of reorganizations and a severe economic recession, several municipalities made cutbacks in their school health service and family planning clinics, which earlier provided adolescents with easy access to contraceptive counseling.14,15 Too little is known about changes in contraceptive counseling in school health service or family planning clinics in the 2000s to draw any conclusions as to whether these contributed to the decreased abortion rate.

Sex education covering the entire age group is important in providing correct and proper information on sexual matters, including contraception and media literacy skills against the hypersexual media information. Health education, the school subject in which sex education is taught, was not compulsory in Finnish schools in the 1990s. When taught, it was integrated into other school subjects. The amendment of the Basic Education Act16 defined health education as its own compulsory school subject from 2004. The national curriculum that all schools have to follow strengthened the role of sex education.17 As a consequence of these changes and the lively discussion in the preparation phase of the legislative proposal, the number of sex education lessons increased in the 2000s compared with the 1990s.18 Well-informed teenagers acquiring their knowledge through school health education may be one of the explanations for the positive changes in sexual behavior and the abortion rate in the 2000s.

Toward the end of the 1990s, actions and media discussion of school-aged children's health in Finnish society was very active when research results showed deteriorating health and health behavior in this age group. For the first time, local research results were available to municipalities, schools, and parents (the present School Health Promotion Study). This activated health-promotion actions targeted at adolescents and likely was to activate parental care and monitoring of teenagers' activities. The growing concern about adolescent health resulted in increased activity and active discussions in the media and among health professionals, teachers, and school authorities as well as the general public and politicians.19 This may have contributed to adolescents' sexual behavior and further to the lower abortion rate.

In Finland, most abortions are performed for what are known as social reasons. These cases require written permission from two physicians. However, if a girl is younger than 17 years old at the time of conception, permission from one physician is enough.20 Abortions are performed in public hospitals in all parts of the country as part of public health care at low cost. During the 1990s and 2000s, the legislation concerning abortions has not changed and neither have the facilities where abortions are performed.

Finally, we should consider the role of alcohol use in adolescents' sexual experiences. Increased alcohol use and binge drinking among teenagers in the 1990s21 may have contributed to the increased unprotected sex and multiple partners22,23; a decrease in alcohol use and binge drinking in the 2000s21 may have had an opposite effect.

This study was based on highly comparable national surveys maintaining similar data collection methods, samples, and questions over the years. The response rates to the current surveys were high, and the 5–10% of pupils who were absent on the survey day, most often because of sickness, would hardly differ from those who responded to the questionnaire. In the analyses, we included only those schools participating in all surveys. There were only minor differences in sexual indicators between the schools joining the study at the very beginning and those joining it later. Our data may underestimate the proportion of sexually active adolescents in the population somewhat. However, if there is a small selection bias, the bias is most likely similar over time and thus has no effect on the comparisons between the surveys. The same applies to the reliability of the questions on sexual behavior. Earlier studies have shown a high repeatability of questions regarding contraception.14 Adolescents report their sexual behavior and contraceptive use reliably over a 6-month interval.24 However, the reliability of self-reported sexual behaviors decreases with the increasing duration of the recall period. If sexual behaviors were underreported in the current study, the underreporting was most likely similar over time and thus has no effect on the comparisons.

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1. Sedgh G, Henshaw S, Singh S, Ahman E, Shah IH. Induced abortion: estimated rates and trends worldwide. Lancet 2007;370:1338–45.

2. Koskinen S, Aromaa A, Huttunen J, Teperi J. Health in Finland. Helsinki: STAKES; 2006. Available at: Retrieved March 23, 2009.

3. STAKES OSF Statistical Summary 27, 2008. Available at: Retrieved March 23, 2009.

4. National institute for Health and Welfare. School health promotion study. Available at: Retrieved March 23, 2009.

5. Ross J, Wyatt W. Sexual behaviour. In: Currie C, Hurrelmann K, Settertobulte W, Smith R, Todd J, editors. Health and health behaviour among young people. Health behaviour in school-aged children. Health Behaviour in School-aged Children (HBSC) study. WHO Policy Series for Children and Adolescents. Copenhagen: World Health Organization; 2000. pp. 115–20.

6. Ross J, Godeau E, Dias S. Sexual health In: Currie C, Roberts C, Morgan A, Smith R, Settertobulte W, Samdal O, et al, editors. Young people's health in context. Health Behaviour in School-aged Children (HBSC) study: international report from the 2001/2002 survey. WHO Policy Series for Children and Adolescents, No. 4. Copenhagen: World Health Organization; 2004. pp. 153–60.

7. Copas AJ, Wellings K, Erens B, Mercer CH, McManus S, Fenton KA, et al. The accuracy of reported sensitive sexual behaviour in Britain: exploring the extent of change 1990–2000. Sex Transm Infect 2002;78:26–30.

8. Ford NJ, Halliday J, Little J. Changes in the sexual lifestyles of young people in Somerset, 1990-1996. Br J Fam Plann 1999;25:55–8.

9. Kangas I, Andersen B, McGarrigle CA, Østergaard L. A comparison of sexual behaviour and attitudes of healthy adolescents in a Danish high school in 1982, 1996, and 2001. Popul Health Metr 2004;2:5.

10. Santelli JS, Lindberg LD, Abma J, McNeely CS, Resnick M. Adolescent sexual behavior: estimates and trends from four nationally representative surveys. Fam Plann Perspect 2000;32:156–65, 194.

11. Zillmann D. Influence of unrestrained access to erotica on adolescents' and young adults' dispositions toward sexuality. J Adolesc Health 2000;27(2 Suppl):41–4.

12. Escobar-Chaves SL, Tortolero SR, Markham CM, Low BJ, Eitel P, Thickstun P. Impact of the media on adolescent sexual attitudes and behaviors. Pediatrics 2005;116:303–26.

13. L'Engle KL, Brown JD, Kenneavy K. The mass media are an important context for adolescents' sexual behavior. J Adolesc Health 2006;38:186–92.

14. Hassani KF, Kosunen E, Rimpelä A. The use of oral contraceptives among Finnish teenagers from 1981 to 2003. J Adolesc Health 2006;39:649–55.

15. Koponen P, Sihvo S, Hemminki E, E EK, Kokko S. Family planning services in Finnish health centres—organisation and women's opinions of services [Finnish]. Sosiaalilääketieteellinen Aikakauslehti 1998;35:220–8.

16. Basic education act 628/1998. Available at: Retrieved March 23, 2009.

17. The Finnish National Board of Education. Available at:,37840,72101,72106. Retrieved March 23, 2009.

18. Liinamo A. Sexual education and sexual health knowledge among Finnish adolescents at pupil and school level—evaluation from the point of view of health promotion. Studies in sport, physical education and health [Finnish]. Jyväskylä: University of Jyväskylä; 2005.

19. Rimpelä A, Raini S, Pere L, Lintonen T, Rimpelä M. Use of tobacco products, alcohol use and exposure to drugs in 1977–2005: Ministry of Social Affairs and Health. 2006. Available at: Retrieved May 11, 2009.

20. Knudsen LB, Gissler M, Bender SS, Hedberg C, Ollendorff U, Sundström K, et al. Induced abortion in the Nordic countries: special emphasis on young women. Acta Obstet Gynecol Scand 2003;82:257–68.

21. Rimpelä A, Lintonen T, Pere L, Rainio S, Rimpelä M. Adolescent health habits 2001, changes in tobacco and alcohol use 1977–2001 [Finnish]. Helsinki: National Research and Development Centre for Welfare and Health (STAKES); 2002.

22. Baskin-Sommers A, Sommers I. The co-occurrence of substance use and high-risk behaviors. J Adolesc Health 2006;38:609–11.

23. Imamura M, Tucker J, Hannaford P, da Silva MO, Astin M, Wyness L, et al. Factors associated with teenage pregnancy in the European Union countries: a systematic review. Eur J Public Health 2007;17:630–6.

24. Sieving R, Hellerstedt W, McNeely C, Fee R, Snyder J, Resnick M. Reliability of self-reported contraceptive use and sexual behaviors among adolescent girls. J Sex Res 2005;42:159–66.

© 2009 by The American College of Obstetricians and Gynecologists.


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