Late Fertility : its Causal Effects on Health of the Newborn and its Implications in Fertility Decision Process

This doctoral thesis is devoted to the study of the effects of late fertility on health of
the newborn and to the implications of late fertility in the fertility decision process.
Late fertility is defined as the reproduction process after 30 years old. The interest lies
as well from the maternal age point of view as from the paternal age point of view.
The first part is devoted to the study of the determinants of infant morbidity and
mortality with a particular attention to the parental age, without neglecting the other
determinants. The originality of this part is located from the methodological point of
view. We construct a structural model of infant morbidity/mortality in order to isolate
the causal effect of late fertility. By a structural model we mean a model which represents
a set of causal relationships represented mathematically by a multi-equation
model and graphically by directed acyclic graphs. As a complementary approach, a
chapter of the thesis is devoted to an exploratory model highlighting the role of the
extreme values rather than average values traditionally of interest in most statistical
analyses. Both methods are tested with Hungarian data: individual registration forms
of livebirths and infant deaths (1984-1984 and 1994-1998), and the Hungarian casecontrol
surveillance of congenital abnormalities (1997-2002).
The second part analyses the effect of parental ageing in the fertility decision process.
We try to determine whether the detrimental effect of late fertility on health of
the child and on fecundity of the couples intervene in the preferences for a child. We
assume that parental age influences the preferences for a child through effects on
the desire for a child and on the beliefs in the capacity of reproduction of a healthy
child. This hypothesis is tested using the data from the National Survey of Family
Growth (United States, 2002) and from the Fertility and Family Survey (Hungary,
Czech Republic and Belgium).