Trends in Adolescent Births in Mexico in the Context of a National Adolescent Pregnancy Prevention Program, 2008-2019

We describe very young adolescent (VYA, 10-14) and adolescent (15-19) births in Mexico before and after the implementation of the National Strategy for the Prevention of Adolescent Pregnancy (ENAPEA in Spanish) in 2015, which has as the goal to halve adolescents' overall fertility and eradicate births in those under 15.

We used administrative birth certificate data, 2008-2019 and calculated the proportions of births and birthrates by age group over time. We then calculated the change in proportion of births and in birthrates before (2008-2014) and after (2015-2019) ENAPEA at national and state level. We used linear regression models to assess association between changes in birthrates and the implementation of ENAPEA. We also calculated the proportion of births that were first versus second- or higher-order births.

Overall, about 20% of births in Mexico are to VYA and adolescents, with little change over time. VYA and adolescent births increased or were stable in the pre-ENAPEA (2008-2014) period and declined in the post-ENAPEA period (2015-2019). Small but significant reductions in birthrates for both age groups are associated with the beginning of the implementation of ENAPEA. There were important reductions in the proportion of births that are second order or higher.

Our results provide some key insights to help understand declines in adolescent births in the context of ENAPEA, with a particular focus on VYA mothers and a novel insight on first and second-/third-order births.