Improved birth outcomes appear strongest for women of
Hispanic origin, with significant improvements in birthweight,
gestational age, and LBW status, but with no
changes in prenatal care. In general, the positive association
of WIC participation and birth outcomes seems stronger for
Blacks than for the White population, and even stronger
when the Hispanic population is removed. Significant benefits
are associated with WIC participation for unmarried
women: improvements in birthweight, gestational age, LBW
status, and adequacy of prenatal care. The trends appear
similar to those for teenage women, many of whom also fall
into this category. An inverse relation between maternal
education and improved birth outcomes is evident. Women
with less than a high school education show significant
improvements in birthweight, LBW status, and adequacy of
prenatal care. Stratification of the sample by birth parity
revealed no consistent pattern.
Increased Duration of WIC Participation-Duration of
prenatal participation in WIC is based on the number of
months between the month of the first redemption of a
voucher and the month of delivery. The mean duration of
prenatal participation in WIC in 1978 was 4.6 months.
The cumulative impact of WIC participation on birth
outcomes was examined in two ways. First, WIC participants
and their matched controls were stratified into three
groups based on absolute number of months in the WIC
program: 33 per cent participated for one to three months; 45
per cent for four to six months; and 22 per cent for seven to
nine months. Second, to compensate partially for differing
lengths of gestation, participants were also stratified into
four groups based on percentage of pregnancy in the WIC