Objectives: Texas birth records and population projections were used to simulate pregnancy rates among women ages 15-19 years from 2005 to 2015.
Methods: Monte Carlo simulation based on historical rates of natural increase, contraceptive failure and sexual experience among racial/ethnic groups of teenaged women was used for numerical projections. These projections were used in a systems dynamics model which posits teen pregnancy risk as a stochastic process of contraceptive failure and sexual activity. The PRI was constructed as a logistic function of sexual experience, the weighted average contraceptive failure rates and time-varying probabilities of natural increase among racial/ethnic sub-groups of adolescent women.
Results: From 2005 to 2015, the number of adolescent, Hispanic females in Texas is expected to increase by 45%. During this same period, the expected pregnancy risk for 15 to 19 year old females is expected to increase to 13% or 127 per 1,000 women. This increase is due largely to the rise in the pregnancy risk among the growing population of Hispanic adolescents.
Conclusions: Changing population characteristics in Texas and differences in sexual activity and contraceptive failure among racial/ethnic groups indicate that teenage pregnancy will not continue to decline in the coming decade. The adolescents most at risk for pregnancy are expected to increase significantly. Pregnancy prevention programs need to be intensified and adapted to the changing Texas social climate in order to preempt dramatic increases in teenage pregnancy.