What's Driving Girls' Adolescent Marriage Decline in Rakai, Uganda? The Interplay between Adolescent Pregnancies and Social Determinants, 1999 - 2018

"To delay adolescent marriage altogether, funding efforts need to shift towards adolescent pregnancy prevention, as well as the structural and social drivers of adolescent pregnancy and marriage in East African contexts like Uganda."

Substantial evidence exists about the cross-sectional associations of social determinants - such as education, socio-economic status (SES), and orphanhood - and adolescent marriage in different contexts. This study examines the factors behind the substantial adolescent marriage declines in Rakai, in the southcentral region of Uganda. Over the last 30 years, this region experienced increased investments in response to the HIV epidemic, infrastructure investment of schools and health centres, and diversified livelihoods and economic opportunities.

The researchers first used repeat cross-sectional data from 15- to 17-year-old girls between 1999 and 2018 to assess the extent to which social determinants were associated with adolescent marriage. This repeat cross-sectional dataset provided a population snapshot of time trends, as well as associations between variables of interest and adolescent marriage. From the repeat cross-sectional data, they then constructed a panel dataset of girls who were consistently followed over time to conduct a causal mediation analysis examining the relationships between education, adolescent pregnancy, and adolescent marriage. This panel dataset provided an individual-level examination of girls' behaviours over time, enabling the researchers to isolate and characterise the sequencing between education, pregnancy, and marriage events among girls who had at least two rounds of survey data.

Between 1999 and 2018, marriage and pregnancy among 15- to 17-year-old girls declined in a parallel trend from 24% to 6%, and 28% to 8%, respectively. The proportion of girls who ever had sex also declined substantially from 62% in 1999 to just 23% in 2018, consistent with declining adolescent pregnancy rates. Household SES rose over time, as did secondary schooling levels, which rose from 35% in 1999 to 54% in 2018. Rates of orphanhood were high and unchanged (>50%) before 2004, then declined steadily through 2018 (21%) following the rollout of HIV treatment in the region in 2004. Over the same time period, both adolescent marriage and pregnancy declined in a parallel downward trend.

Education was strongly associated with adolescent marriage; girls with lower secondary or higher education had 91% lower odds of being married relative to girls with lower primary level or no schooling, adjusting for age and time (adjusted odds ratio (aOR) marriage = 0.09; 95% confidence interval (CI) = 0.07-0.12), accounting for time. Lower pregnancy rates partially explained the effect of secondary schooling on lower adolescent marriage (aOR indirect effect = 0.55; 95% CI = 0.421-0.721). Overall, orphanhood was not strongly associated with marriage in the multivariable model. SES was marginally significantly associated with marriage.

Taken together, these findings show that education continues to be a protective factor in preventing adolescent marriage. Yet, lower pregnancies rates may play an important role in explaining the protective effect of education on adolescent marriages, and in contributing to adolescent marriage trends over time. These findings are in line with calls from researchers and activists to increase efforts and resources towards the role of pregnancy and sexuality-related stigma in perpetuating adolescent marriages.

Of use for future studies, this paper provides an example of a causal mediation approach that unpacks the relationship between education, pregnancy, and marriage. Its methodological approach can be used to examine how social and structural factors - such as economic and educational improvements - are driving large-scale adolescent marriage behaviours, which could be adapted to other population-based cohorts and studies.

Of use for activists and policymakers, this study's longitudinal evidence can be used to advocate for and invest in policies and programmes that focus both on education and pregnancy to prevent adolescent marriages, particularly in the context of Uganda. To end adolescent marriage in Uganda as per Sustainable Development Goal (SDG) Target 5.3, stronger investments towards adolescent pregnancy prevention are especially warranted, including programmes and policies that address norms and issues related to sex, contraception, and sexuality among girls and boys. The role of sexuality education in Uganda has long been at the centre of controversy, yet the findings point to an urgent need to better integrate sexuality education and pregnancy prevention efforts in adolescent marriage policies and programmes.