Teenagers who plan parenthood.

It is clear that a variable number of teenage mothers have, to some extent, planned parenthood. From an evolutionary perspective, it could be argued that teenage childbearing may in fact be a positive adaptive mechanism for humans raised in a hostile environment. Life history theory suggests that in risky and uncertain environments the optimal reproductive strategy is to reproduce early in order to maximise the probability of leaving any descendents at all. If some teenagers are planning or hoping for pregnancy, it is possible that some positive behavioural changes may be observed. This has proven to be the case with many teenagers altering their risk taking behaviours in the anticipation and expectation of pregnancy. There is now substantial evidence that teenagers who become pregnant were at higher risk than the general population for using cigarettes, alcohol, and marijuana. However, once pregnant, rates of consumption are usually lower compared with their non-pregnant peers or even their own personal pre-pregnancy rates of consumption. Therefore, for some teenagers, the conscious or unconscious prospect of pregnancy represents a potential space in which to rethink behaviours that may be harmful to themselves as a future mother, and also to their child. Given that teenage motherhood is not going to simply vanish, it is important to remember to focus research and services on validated interventions that may assist teenage mothers fulfill their ambitions of parenthood and simultaneously provide the best outcomes for their offspring. Evidence-based interventions focus on sustained home visitation by nurses, with limited evidence supporting the use of volunteers. In contrast, evidence suggests that home visitation by paraprofessionals may not be effective. Other strategies that may be helpful include the use of multidisciplinary teenage pregnancy clinics that have been noted to be associated with improved pregnancy outcomes. The role of new mothers' groups, other community based group activities, peer support workers and intensive educational interventions to encourage return to schooling may be useful but have not been subjected to randomised evaluation. Such evaluation needs to occur.