Did England's Teenage Pregnancy Strategy reduce pregnancy rates in England? A Natural Experiment study

ObjectiveTo re-evaluate the impact of Englands Teenage Pregnancy Strategy (1999 to 2010) on pregnancy and birth rates. Hailed as a unique, nation-wide, comprehensive, evidence-based intervention, the strategy has been promoted as a reproducible model for other countries with high teenage pregnancy rates. DesignControlled interrupted time series and synthetic control analyses using routinely collected data on births and abortions in 16 countries. SettingThe Strategy was published in July 1999 and implemented from 2000-2010, with increased investment in areas with higher rates of under-18 pregnancies from 2006 onwards. ParticipantsWomen aged under 20 living in England during the intervention period were considered to be the target population. Women in Scotland and Wales were the control population in our interrupted time series analyses. Women from European and English-speaking high-income countries were the control population in our synthetic control analyses. Main outcome measuresThe pregnancy rate among women aged under-18 was our primary outcome, as this was the target of the Strategy. We used under-18 births and under-20 pregnancies as secondary outcomes. ResultsIn the controlled interrupted time series analyses, trends in rates of teenage pregnancy in England were similar to Scotland (0.08 fewer pregnancies per 1,000 women per year in England; -0.74 to 0.59) and Wales (0.14 more pregnancies per 1,000 women per year in England; -0.48 to 0.76). In synthetic control analyses, under-18 birth rates were very similar in England and the synthetic control. Under-20 pregnancy rates were marginally higher in England than in the synthetic control. Placebo testing and other sensitivity analyses supported the finding of little observable effect. ConclusionAlthough teenage pregnancies and births in England fell following implementation of the Teenage Pregnancy Strategy, comparisons with other countries suggest the strategy had little, if any, effect. This raises doubts about whether the strategy should be used as a model for future public health interventions in England or in other countries aiming to reduce teenage pregnancy. The protocol for the analysis was published online at https://osf.io/tdbr8/ SUMMARY BOXWhat is already known on this topic: O_LITeenage pregnancy is associated with numerous health risks, and efforts to reduce rates of pregnancy may lead to improved health outcomes C_LIO_LIThe Teenage Pregnancy Strategy was launched in 1999 with the goal of reducing teenage pregnancies in England C_LIO_LIInitial observations showed a drop in rate across the strategy period; this has been interpreted as demonstrating the success of the intervention. C_LI What this study adds: O_LIOur study suggests there was little or no effect of the strategy, and that the rapid decline in rates would have occurred without the intervention, in line with similar countries. C_LI