In the United States, the prevalence of women delaying childbearing continues to increase; from 1976 to 1986 the rate of first births among women 40 years of age or older doubled (NCHS and Ventura, 1989). Data on the prevalence of pregnancy above 35 years of age among the WIC population were not available to the committee.
With advancing age, especially after age 35, risks associated with pregnancy increase. Most or all of this is due to the increasing likelihood of medical illnesses in the mother and congenital defects (i.e., chromosomal abnormalities) in the fetus (Berkowitz et al., 1990; Cefalo and Moos, 1988; Fretts et al., 1995). The extent of risk attributable specifically to nutrition in older mothers is highly questionable.
Although medical complications of pregnancy increase with increased age, and yield of risk would be high, there is little evidence of nutrition benefit from WIC participation and the services offered by the program.
The risk of pregnancy age older than 35 years is well documented in women, and this condition can be identified easily. However, there is no theoretical or empirical basis for benefit from participation in the WIC program. Therefore, the committee recommends discontinuation of use of pregnancy age older than 35 years as a nutrition risk criterion for women in the WIC program.
Closely spaced pregnancies are commonly defined using either of two indicators: short interpregnancy interval (birth to conception interval), or short birth interval (the interval between the previous and sampled births). The interpregnancy interval is not affected by the length of gestation of the second pregnancy.