Timing of fertility among recent migrants to England and Wales

James Robards, University of Southampton
Ann M. Berrington, University of Southampton

Births to non-UK born mothers have played an important contributory role in the recent increase in fertility in the UK (Tromans et al. 2009; ONS, 2013). Total fertility rates (TFRs) among overseas born women tend to be much higher than those of UK-born women and often higher than TFRs in the country of origin (Dorman, 2014). However, TFRs calculated for non-UK born women can be potentially misleading since the timing of childbearing is often related to migration. Studying the timing of fertility with reference to the date of migration in England and Wales has been difficult because of the hitherto lack of appropriate data sources which contain both information on date of arrival and fertility histories. The 2011 Census asked non-UK born respondents the month and year of first residence in the UK. By combining these data with linked information on childbearing available within the ONS Longitudinal Study this paper contributes to the literature by estimating the fertility of migrants before and after migration. The paper provides new insights by (1) estimating the fertility of migrant groups to England and Wales before migration, (2) examining whether there is evidence of an acceleration of childbearing around the time of the migration and (3) identifying which migrants are likely to have a birth within the first five years after migration to England and Wales. Our findings suggest important timing changes in childbearing associated with the migration event which mean that standard period measures of fertility among these groups can be a misleading indicator of overall life time fertility. These timing changes appear to differ according to the type of sending country. We discuss these findings in terms of their implications for understanding overall fertility trends in the UK.