From 'sugar daddies' to 'sugar babies': exploring a pathway among age-disparate sexual relationships, condom use and adolescent pregnancy in South Africa

Background: Adolescent pregnancy has been linked to adverse outcomes. Most studies proposing risk pathways for adolescent pregnancy in South Africa are qualitative, hypothesising links among age-disparate relationships, reduced condom use and higher pregnancy rates. No known South African studies have quantitatively explored pathways to adolescent pregnancy. Objectives: This study aimed to: (i) identify the factors associated with adolescent pregnancy and (ii) explore a pathway of risk by assessing whether condom use mediated the relationship between age-disparate sexual relationships and adolescent pregnancy. Methods: A cross-sectional survey of 447 sexually active girls aged 10-19 years was undertaken in six health districts of South Africa. Multivariate logistic regressions controlled for confounders. Mediation tests used bootstrapping. Results: Consistent condom use (beta = -2.148, odds ratio (OR) = 8.566, P <= 0.001) and school enrolment (beta = -1.600, OR= 0.202, P <= 0.001) were associated with lower pregnancy rates. Age-disparate sex (beta = 1.093, OR= 2.982, P <= 0.001) and long-term school absences (beta = 1.402, OR= 4.061, P <= 0.001) were associated with higher pregnancy rates. The indirect effect of age-disparate sex on adolescent pregnancy through condom use was significant, irrespective of age, age at sexual initiation, poverty and residential environment (B = 0.4466, s.d. = 0.1303, confidence interval: 0.2323-0.7428). Conclusion: This survey supports hypotheses that inability to negotiate condom use in age-disparate sexual relationships may drive adolescent pregnancy. Interventions addressing these relationships, facilitating condom use and increasing access to sexual health services among adolescents might avert unwanted pregnancies.