|Trinidad & Tobago||2.7||18.9|
|Sources: United Nations 1988.|
|Notes: IMR = Infant Mortality Rate; low = <2.9; moderate = 3.0-3.9; high =|
4.0-5.9; very high = 6.0+.
All the international literature reviewed by this author shows greater risk to maternal and child health for births of high order, births to women at the extremes of their reproductive years, and births occurring after short intervals. In the high-risk categories of birth order and maternal age, a greater proportion of births are to women in the lower socio-economic groups. However, this fact is not sufficient to explain the differentials, because the pattern of the rates persists even within those socio-economic groups. And with the exception of birth trauma and accidents, the differentials in infant mortality by birth order and age of mother also hold for the different groups of causes of neonatal and post-neonatal death.
The main problems in estimating the effect of fertility decline on infant health stem from the lack of data and the complexity of the relationships and interactions among multiple explanatory and intervening variables. Since there are few countries for which vital statistics data can be used for estimation, it has been necessary to make use of survey data, especially data from the WFS. Part of the explanation for the discrepancies among the findings of various researchers who have examined the risk of infant mortality of first-born children compared with that of subsequent birth orders might be the different distributions of first-order