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Teenage pregnancy

Interventions to reduce the rate of teenage pregnancy - Schools

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Schools have advantages as settings for interventions to prevent teenage pregnancy because most young people are attending full time education at the time they reach sexual maturity. Furthermore, the subject can be taught alongside related subjects such as biology and social responsibility and the wider aspects dealt with. Moreover, many parents feel ill-equipped to deal with their children's needs for information and prefer to leave the task to schools. In addition, school is the preferred source of sex education for young people themselves. 1

Reviews of the effectiveness of school sex education programmes 2 show that provision of advice about sex and contraception is not associated with an increase in teenage sexual activity or pregnancy rates. However, there is also evidence that improving knowledge about sexual health does not necessarily lead to changes in related behaviours, and that changing sexual lifestyles and behaviours is a more complex and challenging task than merely improving knowledge. Although some of the determinants of teenage pregnancy operate at an individual level, others relate to the broader social context and include the level of deprivation of the area in which young people live, and the opportunities provided locally for improving and exploiting life chances. The broader social structural determinants of early pregnancy need to be addressed in interventions.



In this section:

Key Messages

  • Evidence from intervention trials (conducted mainly in the US) on the effectiveness of sex education programmes varies according to study methods.
  • An early review of sexual health promotion interventions for young people, conducted in the mid 1990s, 3 found that only 12 (18%) of 65 studies evaluating the outcome of interventions were considered methodologically sound and only two of the sound evaluations showed an impact on self-reported sexual behaviour.
  • One review found that on comparable outcomes, observational studies yielded systematically greater estimates of intervention effects than randomised trials. It is unlikely that interventions in the observational studies were more effective than those studied in randomised trials. Therefore, wherever possible, recommendations and public policy should be based on randomised trials. 4
  • The evidence is that effective interventions are likely to be those in which school-based sex education are more broadly-based and are integrated with community level interventions and contraceptive services, sex educational programmes are targeted at young people at greatest need, and there is outreach involvement.

Population Interventions

Population interventions that work

Multifaceted sex education interventions

The evidence is that more broadly-based sex education programmes achieve better results, although, paradoxically, the wider the scope of the programme, the less amenable it is to an experimental evaluation design. For this reason, multifaceted sex education interventions are under-represented in the research literature.

There were significantly fewer pregnancies in young women who received a multifaceted programme (0.41; 0.20 to 0.83), although baseline differences in this study favoured the intervention. 5

A RCT of a United States programme, “Safer Choices,” which combined classroom sex education with other components such as involvement of parents, and school-community links, had more success in increasing levels of safer sex than a more narrowly-based programme. 6

Systematic reviews and individual RCTs have shown that sex education is more successful when linked to access to contraceptive services than when provided alone. The evidence supports linking sex education in the classroom with local sexual health service provision, for example, by organising school group visits to local clinics or providing clinics on schools premises. 7 8 9

Targeted approaches have also been shown to be more effective, particularly those addressing black and minority ethnic groups. A RCT of sexually experienced African American girls aged 14-18 received four 4-hour group sessions of an intervention emphasising ethnic and gender pride, HIV knowledge, communication, condom use skills, and healthy relationships. Compared with the comparison group, which emphasized exercise and nutrition, those in the intervention group reported less unprotected sex and fewer sexual partners, and promising effects were observed for self-reported pregnancy. 10

See Factfile: Safer Choices

Population interventions that may work

Peer-led sex education

Two large well-conducted cluster randomised controlled trials have been conducted in the past decade in England and Scotland, and neither has shown a significant impact on pregnancy levels. 11 12

The first, a large RCT in England that was funded by the Medical Research Council, compared the effectiveness of peer-led sex education (intervention) with the usual teacher led sex education. 11 27 schools in central and southern England, and over 9000 pupils, took part in the RIPPLE trial. The peer led sex education had no effect on the timing of first sexual intercourse, but it did succeed in reducing levels of unprotected sex before age 16 among girls, although not among boys. At follow-up, girls receiving peer-led sex education reported fewer unintended pregnancies, but the difference was borderline (2.3% compared to 3.3%, P=0.07).

The second, a Scottish theoretically-based sex education programme (SHARE) delivered by teachers, was evaluated by means of a cluster randomised trial with follow-up two years after baseline. 25 state schools in Tayside and Lothian regions and over 7000 pupils participated in the SHARE trial. Sexual activity or sexual risk taking by age 16 years did not differ between intervention group and conventional sex education group. 12 Overall, 41% of all girls and 31% of all boys reported having had sexual intercourse at follow-up (average age 16 years and 1 month) of whom over 70% of girls and 78% of boys used a condom at first sex. However, there was no significant difference in reported sexual intercourse, condom or contraceptive use between those allocated to the SHARE programme and those in the control group. 5.2% of all boys in the intervention group and 5.7% in the control group reported first intercourse without a condom at follow-up (p=0.63); corresponding figures for the girls were 9.7% and 9.1% (p=0.66). Lack of an effect on sexual behaviour could not be linked to differences between schools in the quality of delivery of the intervention. The authors concluded that the impact of a 20-period schools sex education was probably relatively unimportant compared with long term and pervasive influences from family, local culture and the mass media. Due largely to its popularity with pupils and teachers, the SHARE programme is increasingly being implemented in schools across Scotland.

However, all methodological problems need to be borne in mind in interpreting the evidence of relatively modest and short term effects of sex education on teenage pregnancy rates. One problem in assessing the impact of school-based sex education in preventing teenage pregnancy is that of finding a “pure” control group to use to assess efficacy. Virtually all schools provide some sex education; there are no “non-exposed” schools.

A further problem relates to outcome measures used in evaluation studies and stems from the potentially long interval between receipt of sex education and the endpoint of teenage pregnancy. Education about sexual matters is one factor among many that may intervene to influence the outcome, such as uptake and provision of contraceptive services. Few evaluation studies have a follow-up that exceeds two years and so are obliged to use “upstream” measures of outcome - such as changes in knowledge - or behaviours - such as onset of sexual activity or use of contraception - which cannot be guaranteed to predict the ultimate outcome. This may explain why few systematic reviews have shown school-based sex education to have had an appreciable effect on teenage pregnancy rates.

Prevention strategies

A systematic review carried out in the US pooled findings from 26 randomised trials of interventions to reduce unintended pregnancies among adolescents, some of which were school-based. 13 Strategies evaluated did not delay the start of sexual intercourse, or improve use of contraception or reduce pregnancies in young women. 13

A further meta-analysis found small improvements in sexual risk reduction skills and behaviours in adolescents after intervention, although average follow-up was only 14 weeks and 23% of studies did not randomise participants to intervention or comparison groups, which would weaken their findings. 14

Finally, a systematic review of 26 trials of the effectiveness of primary prevention strategies showed that they neither delayed initiation of sexual intercourse nor improved use of birth control, and did not reduce pregnancy rates in young women. 5

Clearly, school sex education alone has limited effectiveness in reducing teenage pregnancy. Incorporating educational approaches that enable young people to initiate sex at an optimal time in terms of consensuality, protection, autonomy, and freedom from regret may enhance the effectiveness of sex education; but such methods have not been evaluated as yet. (See also below: abstinence).

Population interventions that do not work

Abstinence-based sex education programmes

Interest in the effectiveness of abstinence-based sex education programmes is growing, fuelled by the Bush administration’s endorsement and funding of them in the United States and Uganda. This has given rise to several studies comparing school-based abstinence-only programmes with comprehensive programmes (including contraceptive information), to determine which has the greatest impact on teenage pregnancy. 5 There is as yet no evidence that abstinence-only programmes delay the onset of intercourse or pregnancy. 13

One RCT showed a very small effect on pregnancy rates 15 but a meta-analysis of five abstinence programmes showed at best no effect, and at worst, an increase in the number of pregnancies in the partners of young male participants. 5 More needs to be known about what exactly constitutes abstinence-only programmes, and whether the concept of readiness should be better integrated into comprehensive programmes among partners of young male participants. 5

What we don’t know

Since deprivation is such an important determinant of teenage pregnancy, the impact of provision of information and advice to influence teenage pregnancy rates is limited. A major challenge remains that of addressing the broader social structural determinants of early pregnancy in interventions, and we need evidence on how this might best be affected. Factors like poverty, unemployment and gender are harder to modify and lie outside the scope of interventions with a more narrow health focus. They demand the involvement of social as well as health sectors and so require co-ordination and collaboration across sectors and agencies, and with other social interventions.

Teenage pregnancy strategy

The government’s teenage pregnancy strategy is explicitly promoting joint action between agencies and sectors to this end. The aims of the strategy, to bring about a 50% decline in rates of under 18 pregnancy by 2010, and to reduce social exclusion among young parents, are ambitious. Since the inception of the strategy, however, England has seen the first sustained decline in under 18 conception rates in two decades. 16

References

  1. Macdowall W, Wellings K, Mercer CH, Nanchahal K, Copas AJ, McManus S, et al. Learning about sex: results from Natsal 2000. Health Educ Behav. 2006;33:802-11. External Link
  2. Kirby D. Understanding what works and what doesn’t in reducing adolescent sexual risk-taking. Fam Plann Perspect 2001;33:276-81. External Link
  3. Oakley A, Fullerton D, Holland J, Arnold S, France-Dawson M, Kelley P, et al. Sexual health education interventions for young people: a methodological review. BMJ 1995;310:158-62. External Link
  4. Guyatt GH, DiCenso A, Farewell V, Willan A, Griffith L. Randomized trials versus observational studies in adolescent pregnancy prevention. J Clin Epidemiol 2000;53:167-74. External Link
  5. Bennett SE, Assefi N P, School-based teenage pregnancy prevention programs: a systematic review of randomized controlled trials. J Adolesc Health 2005;36:72-81. External Link
  6. Basen-Engquist K, Coyle KK, Parcel GS, Kirby D, Banspach S W, Carvajal S C, et al. Schoolwide effects of a multicomponent HIV, STD, and pregnancy prevention program for high school students. Health Educ Behav 2001;28:166-85. External Link
  7. Franklin C, Grant D, Corcoran J, O'Dell, Miller P, Bultman L. Effectiveness of prevention programs for adolescent pregnancy: a meta-analysis. CRD abstract 1997;59(3):551-67. External Link
  8. NHS Centre for Reviews and Dissemination. Prevention and reducing the adverse effects of unintended teenage pregnancies. Effective Health Care Bull 1997;1:1-12. Available at; External Link
  9. Lister-Sharp D, Chapman S, Stewart-Brown S, Sowden A. Health promoting schools and health promotion in schools: two systematic reviews. Health Technol Assess 1999;3:1-207. External Link
  10. DiClemente RJ, Wingood GM, Harrington KF, Lang DL, Davies SL, Hook EW, et al. Efficacy of an HIV prevention intervention for African American adolescent girls: a randomized controlled trial. JAMA 2004;292:171-9. External Link
  11. Stephenson JM, Strange V, Forrest S, Oakley A, Copas A, Allen E, et al. Pupil-led sex education in England (RIPPLE study): cluster-randomised intervention trial. Lancet 2004;364:338-46. External Link
  12. Wight D, Raab GM, Henderson M, Abraham C, Buston K, Hart G, et al. Limits of teacher delivered sex education: interim behavioural outcomes from randomised trial. BMJ 2002;324:1430-3. External Link
  13. DiCenso A., Guyatt G, Willan A, Griffith L. Interventions to reduce unintended pregnancies among adolescents: systematic review of randomised controlled trials. BMJ 2002;324:1426. External Link
  14. Johnson BT, Carey MP, Marsh KL, Levin KD, Scott-Sheldon LA. Interventions to reduce sexual risk for the human immunodeficiency virus in adolescents, 1985-2000: a research synthesis. Arch Pediatr Adolesc Med 2003;157:381-8. External Link
  15. Cabezon C, Vigil P, Rojas I, Leiva ME, Riquelme R, Aranda W, et al. Adolescent pregnancy prevention: An abstinence-centered randomized controlled intervention in a Chilean public high school. J Adolesc Health 2005;36:64-69. External Link
  16. Wilkinson P, French R, Kane R, Lachowycz K, Stephenson J, Grundy C, et al. Teenage conceptions, abortions and births in England, 1994-2003, and the national teenage pregnancy strategy. Lancet 2006;368:1879-86. External Link

Contributors

Professor Kaye Wellings

Teenage Pregnancy

Kaye Wellings is Professor of Sexual Health at the London School of Hygiene and Tropical Medicine. She was one of the founders, in 1987, of the National Survey of Sexual Attitudes and Lifestyles (NATSAL) in Britain and Principal Investigator on both the first (1990) and second (2000) surveys. Her team carries out research in the field of sexual and reproductive health and is currently evaluating the Government’s Teenage Pregnancy Strategy and a programme of condom initiatives for the National Assembly of Wales. They are also developing a measure of unplanned pregnancy for use in national prevalence estimates, and investigating attitudes towards long-term contraception.