INTRODUCTION
The timing of childbearing is of interest as it affects the rate of population replacement.
A trend towards delaying first births towards age thirty is a common feature of the
decline in fertility rates in developed countries at the end of the twentieth century
(Gustafsson 2001, Lestaeghe 2001, Sobotka 2004, for example). It is also of particular
interest in those countries, such as the US and UK where early childbearing is still
relatively common (Chandola et al 2002), for its socio-economic covariates (Ekert-Jaffe
et al 2002, Rendall et al 2004). Least advantaged women still tend to have children
earlier and the most advantaged to defer childbearing. This social polarization in the age
at motherhood has emerged in Britain as the trend towards later childbearing in the last
three decades of the century has affected various social groups differentially, and has
differential consequences. This paper examines the diversity of the characteristics and
circumstances of a large sample of British mothers at the start of the twenty-first century,
with a view to exploring and interpreting the socio-economic profile of the age at
motherhood.
There are many studies of the socio-economic determinants of the timing of motherhood
(e.g. Rendall and Smallwood (2003), Ermisch and Pevalin (2003a), Rendall et al 2003,
Rendall et al (in submission), Kiernan (1992, 1997)). In particular, early teenage
motherhood is associated with exclusion from both employment and education (Bynner
& Parsons 1999). Much has been written about the consequences of entering motherhood
early or late not only in terms of outcomes for the mother herself but also for the child,
the father and the state (Social Exclusion Unit 1999, US evidence can be found in