A link between unintended conception and infant mortality has been made using population-based data from a variety of sources and with a variety of methods. For example, using data from the NSFG and other surveys, it was estimated that if all sexually active couples had routinely used effective contraception in 1980, there would have been almost 1 million fewer abortions (533,000 rather than 1.5 million), 340,000 fewer live births that were unintended at conception, 5,000 fewer infant deaths, and a reduction in the infant mortality rate of 10 percent (World Health Organization, 1987). Another method to estimate the impact of unintended conception on infant mortality is to infer decreases in unintended pregnancies from changes in the characteristics of women giving birth. Using this methodology, about one-third of the decline in infant mortality between 1960 and 1968 was attributed to change in the distribution of live births by maternal age and birth order (Wright, 1975). A third method is to correlate changes in infant mortality over time with other temporal changes. Using this methodology, Grossman and Jacobowitz (1981) determined that between 1966 through 1968 and 1970 through 1972, the single most important factor associated with declining neonatal mortality (death in the first 28 days following birth) among both black and white infants was the increasing availability of induced abortion. Similarly, Joyce (1987) estimated that a decade later the reduced incidence of low birthweight and preterm births among black infants in 1977 was mostly associated with the availability of family planning clinics which helped women to avoid a birth unintended at conception.
More recent estimates of the impact of family planning and abortion services on low birthweight and infant mortality suggest continued benefit (Meier and McFarlane, 1994). Although the evidence of the public health value of current family planning programs argues for their continuation and expansion (Klerman and Klerman, 1994), the gap between existing services and the theoretical benefit of all conceptions being intended is enormous.
To sustain normal health and development, children need a wide variety of resources that support cognitive stimulation and development, as well as affective and relational development. Baydar and Grady (1993) hypothesized that children born after mistimed or unwanted conceptions have fewer such resources. Using data from the NLSY, they tested this hypothesis for 1,545 children at two points in their development: at 0–2 and 3–5 years of age. The conceptions of approximately one-third of the children had been mistimed; about 5 percent of the conceptions had been unwanted. The study revealed significant deficits in the