Adolescent pregnancy has been the target of various studies because it elicits innumerable questions. In developed societies it is considered a serious social problem that is associated with low schooling, precarious employment, and poverty. Reproductive health remains a priority issue for European Union (EU) member states even at a time when pregnancy-related mortality rates are at historically low levels. Although the mean age of mothers at the time they give birth, an important determinant of maternity outcome, is increasing throughout the EU, there is a worrisome persistent increase or stability in teenage pregnancy (Ferrinho, Bugalho, & Pereira, 2004).
Portugal has seen a sustained downward trend in teenage pregnancies since the mid-eighties when specific health service measures were introduced for teenagers and improvement in family planning reduced the number of unwanted pregnancies (Mendonca & Calado, 2002). Nevertheless, in 2003 approximately 6,144 Portuguese infants were born to adolescent mothers and 5.5% of all births were from mothers under age 20 (INE, 2003). Portugal has the second highest teenage birth rate in the former 15 European Union member states (UNICEF, 2001).
In the era of information and availability of contraceptive methods, why do adolescents get pregnant? Consistent with pluralist and multi-factorial development theory and models, adolescent pregnancy is seen as a multidetermined phenomenon with different developmental outcomes. Similar to what is postulated in the principles of equifinality and multifinality of general system theory (von Bertalanffy, 1968), different courses can lead to pregnancy during adolescence and different trajectories are drawn from there. Therefore, in lieu of looking for the determinants of adolescent pregnancy, it is preferable to study the different risk and protective factors involved.
Several authors (Corcoran, 1999; Corcoran, Franklin, & Bennett, 2000; Pistole, 1999; Scaramella, Conger, Simons, & Whitbeck, 1998) have claimed the importance of a relational approach to studying risk for adolescent pregnancy. The present study assumes both a relational and ecological perspective. Bronfenbrenner (1979, 1987) believes that comprehension of human development requires "the analysis of multi-personal interractional systems, that are not restricted to only one environment" (p. 40). Although an ecological perspective considers the influence of contexts in which children do not participate, this perspective also predicts that the relationships that form a direct part of the child's and adolescent's life are those that have a most profound influence (Cauce, Reid, Landesman, & Gonzales, 1990). A series of studies identified three main "support systems" in adolescence: family, friends, and school (Cauce, Mason, Hiraga, & Liu, 1994). The following is a brief review of the relational factors of familial and extra-familial contexts that are antecedents to and associated with adolescent pregnancy.
Concerning the familial context, most studies focus on sociodemographic characteristics and family structure. These studies (Coley & Chase-Lansdale, 1998; Hardy & Zabin, 1991; Marlove, 1997; Miller, 2002; Woodward, Fergusson & Horwood, 2001; Yampolskaya, Brown, & Greenbaum, 2002) support the view that there is a large incidence of pregnancy in adolescents raised by single parents, by parents with low educational attainment and low income, and in adolescents from larger families. The existence of adolescent pregnancy/ maternity models in the family is another variable that seems to have influence. The pregnancy in this life cycle period occurs more frequently in daughters of mothers with an adolescent pregnancy history (Manlove, 1997; Woodward et al., 2001) and in sisters of adolescent mothers (Records, 1993). This suggests the existence of intergenerational patterns in teenage motherhood. …