Table 4 Effects of interventions on unintended teen pregnancy outcomes
| Review, year | Intervention description and comparisons | Outcomes | Study (number of participants) | Results | GRADE or risk of bias assessment results |
|---|---|---|---|---|---|
| 1. Skills building interventions | |||||
| Lopez et al. 2016 [39] | A skills-based HIV, STI and pregnancy prevention curriculum compared to standard school-based activities by community-based agency presenters. | Use of effective protection against pregnancy at last sex (condom, oral contraceptive or both) | Low quality | ||
| (Reported by Coyle et al. 2001 [17]) | 7 months after baseline | (n=998) | aOR: 1.62 ± 0.22; p=0.03 | ||
| 31 months after baseline | (n=549) | aOR: 1.76 ± 0.29; p=0.05 | |||
| Condom use at first sex | Low quality | ||||
| 7 months after baseline | (n=285) | aOR: 0.68 ± 0.48; p=0.42 | |||
| 31 months after baseline | (n=733) | aOR: 1.44 ± 0.27; p=0.17 | |||
| Condom use at last sex | Low quality | ||||
| 7 months after baseline | (n=1018) | aOR: 1.91 ± 0.27; p=0.02 | |||
| 31 months after baseline | (n=549) | aOR: 1.68 ± 0.25; p=0.04 | |||
| Frequency of sex without a condom in the past 3 months | Low quality | ||||
| 7 months after baseline | (n=963) | aRM: 0.50 ± 0.31; p=0.03 | |||
| 31 months after baseline | (n=1371) | aRM: 0.63 ± 0.23; p=0.05 | |||
| Attitude towards condoms | Low quality | ||||
| 7 months after baseline | (n=3510) | aMD: 0.10 ± 0.03; p=< 0.01 | |||
| 31 months after baseline | (n=3751) | aMD: 0.07 ± 0.02; p=0.01 | |||
| A school-based intervention combining active learning, information provision and skill development (Reported by Wight et al. 2002 [76]) | Unintended pregnancy at 6 months post-intervention | (n=2117) | 4.0% intervention vs. 3.8% control group | Low quality | |
| Oral contraception use during last sex at 6 months post-intervention | (n=1269) | 30.4% intervention vs. 28.0% control group | Low quality | ||
| Condom use at first sex (12 months post-intervention) | (n= 2629) | 9.7% % intervention vs. 9.1% control group | Low quality | ||
| Condom use at first sex (12 months post-intervention) | (n=1269) | 44.9% % intervention vs. 44.0% control group | Low quality | ||
| Oringanje et al., 2016 [52] | In-person sessions on health/STI education, skills building and contraceptive education | Unintended pregnancy | (n=484) |
Philliber et al. 2002 [53] aRR: 0.59 (0.37, 0.94) |
Moderate quality |
| (n=453) |
Howard et al. 1990 [33] aRR: 0.48 (0.11, 2.09) |
Moderate quality | |||
| (n=312) |
Kirby et al. 1997 [36] aRR: 0.86 (0.36, 2.05) |
Moderate quality | |||
| (n=1887) |
Wight et al. 2002 [76] aRR: 0.78 (0.51, 1.20) |
Moderate quality | |||
| 2. Peer-led interventions | |||||
| Lopez et al., 2016 [39] | A school-based peer-led sex education program vs. usual teacher-led sex education (reported by Stephenson et al. [65]) | No unintended pregnancy (18 months after intervention) | (n=1621) | aOR: 1.40 (0.97 to 2.02) | Very low quality |
| Ever had pregnancy (54 months after intervention) | (n=1338) | aOR: 0.62 (0.42 to 0.91) | Very low quality | ||
| Ever had unwanted pregnancy (54 months after intervention) | (n=1358) | aOR: 0.69 (0.44 to 1.07) | Very low quality | ||
| Ever had an abortion (54 months after intervention) | (n=1359) | aOR: 0.56 (0.31 to 1.02) | Very low quality | ||
| Contraception use during first sex (6 months after intervention) | (n=230) | aOR: 1.14 (0.81 to 1.62) | Very low quality | ||
| Contraception use during first sex (18 months after intervention) | (n605) | aOR: 0.90 (0.73 to 1.11) | Very low quality | ||
| Knowledge of EC pill timing (18 months after intervention) | (n=1,784) | aOR: 1.08 (0.78 to 1.50) | Very low quality | ||
| Knowledge of EC pill timing (54 months after intervention) | (n=1378) | aOR: 0.93 (0.66 to 1.32) | Very low quality | ||
| Lopez et al., 2016 and Oringanje et al., 2016 [39] and [52] | A peer-led intervention focusing on HIV and pregnancy prevention activities (reported by Kirby et al. 1997 [22]) | Oral contraception use at last sex | Moderate quality | ||
| 5 months post-intervention | (n=229) | aOR: 0.73 (0.42, 1.27); p=0.27 | |||
| 17 months post-intervention | (n=354) | aOR: 0.57 (0.36, 0.91); p=0.02 | |||
| Condom use at last sex | Moderate quality | ||||
| 5 months post-intervention | (n=233) | aOR: 0.78 (0.46, 1.34); p=0.37 | |||
| 17 months post-intervention | (n=353) | aOR: 0.76 (0.49, 1.18); p=0.22 | |||
| Pregnancy | Moderate quality | ||||
| 5 months post-intervention | (n=1402) | aOR: 1.53 (0.66, 3.55); p=0.33 | |||
| 17 months post-intervention | (n=1482) | aOR: 0.82 (0.34, 1.99); p=0.66 | |||
| Knowledge of HIV and pregnancy prevention | Moderate quality | ||||
| 5 months post-intervention | (n=1460) | MC: 0.59 intervention vs 0.07 control; p<0.001 | |||
| 17 months post-intervention | (n=1529) | MC: 0.89 intervention vs 0.53 control; p<0.001 | |||
| Mason-Jones et al., 2016 [43] |
Peer-led education intervention focuses on HIV prevention, communication, and reproductive health. (Reported by Cowan et al., 2010 [16]) |
Pregnancy following intervention | (n=2586) | aRR: 0.95 (0.72, 1.26) | Moderate quality |
| Sexual debut following the intervention | (n=2506) | aRR: 1.01 (0.88, 1.15) | Moderate quality | ||
| Condom use at first sex | (n=2491) | aRR: 0.98 (0.87, 1.11) | |||
|
Trained peer educators delivered sessions on sexual health topics. (Reported by Stephenson et al. 2008 [65]) |
Pregnancy | (n=4646) | aRR: 0.80 (0.63, 1.03) | Moderate quality | |
| Condom use at first sex | (n=1736) | aRR: 0.98 (0.93, 1.05) | Moderate quality | ||
| Condom use at last sex | (n=1550) | aRR: 1.01 (0.93, 1.11) | Moderate quality | ||
| 3. Interactive program interventions | |||||
| Lopez et al., 2016 [39] | An interactive program addressing choice, body development, contraception, and parenthood (reported by Taylor et al. [69]) | Pregnancy at 4 months after intervention | (n=129) | 6.3% intervention vs. 4.4% control group | Very low |
| Any condom use at 4 months after intervention | (n=129) | 54.2% intervention vs 36.7% control group; < 0.01 | Very low | ||
| Condom use consistency (4-point scale) | (n=129) | Mean score: 2.34 ± 1.29 | Very low | ||
| Attitude toward teen pregnancy (4-point scale) | (n=679) | Mean score: 2.26 ± 0.82 | Very low | ||
| 4. Abstinence interventions | |||||
| Oringanje et al. 2016 and Mason-Jones et al., 2016 [52] and [43] | In-person sessions on health/STI education, skills building and contraceptive education (reported by Cabezon et al. 2005 [12]) | Unintended pregnancy | (n=460) | aOR: 0.20 (0.10, 0.39) | Moderate quality |
| Mason-Jones et al., 2016 [43] | Promoted abstinence until marriage through a teacher-delivered program | Pregnancy | (n=365) | aRR: 0.18 (0.08, 0.39) | Low quality |
| (Reported by Cabezon et al. 2005 [12]) | |||||
| (Reported by Duflo et al. [22]) | Pregnancy | (n=2754) | aRR: 0.95 (0.72, 1.26) | Moderate quality | |
| Sexual debut following the intervention | (n=6022) | aRR: 0.95 (0.82, 1.09) | Moderate quality | ||
| 5. Delaying sexual debut interventions | |||||
| Mason-Jones et al., 2016 [43] | Advised students to delay sexual intercourse and encouraged condom use (Reported by Henderson et al. [30]) | Pregnancy | (n=4196) | aRR: 1.03 (0.75, 1.40) | Moderate quality |
| Sexual intercourse delay | (n=2680) | aRR: 0.96 (0.85, 1.10) | Moderate quality | ||
| Condom use at first sex | (n=2629) | aRR: 0.99 (0.97, 1.02) | Moderate quality | ||
| Condom use at last sex | (n=1269) | aRR: 0.98 (0.88, 1.11) | Moderate quality | ||
|
Provided knowledge and skills for delaying sexual debut, reducing risk-taking and improving health service use (Reported by Bonell et al., 2013 [11] |
Unintended pregnancy | (n=2940) | aRR: 1.06 (0.83, 1.37) | Moderate quality | |
| Sexual debut delay | (n=2940) | aRR: 1.00 (0.93, 1.08) | Moderate quality | ||
| Condom use at last sex | (n=2134) | aRR: 1.23 (0.94, 1.61) | Moderate quality | ||
| 6. Counselling interventions | |||||
| Oringanje et al., 2016 [52] | In-person sessions on health/STI education, skills building and contraceptive education (Reported by Herceg-Brown et al. 1986 [31]) | Unintended pregnancy | (n=374) | aRR: 0.96 (0.56, 1.65) | Moderate quality |
| 7. Exposure to parental responsibilities interventions | |||||
| Oringanje et al., 2016 [52] |
In-person sessions on health/STI education, skills building and contraceptive education (Reported by Bonell et al., 2013 [11]) |
Unintended pregnancy | (n=408) |
aRR: 0.77 (0.33, 1.79) aRR: 0.50 (0.28, 0.88) aRR: 1.16 (0.88, 1.54) |
Moderate quality |
| 8. Information only interventions | |||||
| Oringanje et al., 2016 [52] | Educational sessions aimed at providing information on sexual risk reduction (reported by Morison-Beedy et al.) | Unintended pregnancy | (n=639) | Moderate quality | |
| Consistent condom use | (n=484) | Consistent condom use | |||