Pregnancy Intention and Preterm Birth: Differential Associations Among a Diverse Population of Women

Women who did not intend their pregnancy had an elevated likelihood of preterm birth (Table 2, page 69). Compared with those whose pregnancy was intended, women who were unsure about their pregnancy were at higher risk of preterm birth (odds ratio, 1.4), as were those reporting their pregnancy as unwanted (1.4) or mistimed (1.2). The risk of preterm birth was associated with unintendedness among white women (unsure, 1.4; unwanted, 1.7; and mistimed, 1.4) and among immigrant Latinas (unsure, 1.6), but not among black or U.S.-born Latina women. Thus, multivariate analyses are presented only for whites and immigrant Latinas. Amongwhitewomen, adjustment for income alonehad the greatest effect on the likelihood of preterm birth, resulting in nonsignificant odds ratios for all categories of pregnancy intention (Table 3). With the addition of maternal education, paternal education or marital status, the relationship between unintended pregnancy and preterm birth was attenuated: Women who reported an unwanted pregnancy—but not those who reported being unsure about the pregnancy or those who considered their pregnancy mistimed—were at higher risk of preterm birth than were women who reported an intended pregnancy (odds ratio, 1.5 in each model). Adding age or parity did not influence the observed association between any of the pregnancy intention categories and preterm birth risk, and did not make a significant contribution to the model with pregnancy intention alone, according to the log-likelihood ratio test (not shown). Adjusting for all socioeconomic factors simultaneously resulted in nonsignificant odds ratios for all categories of pregnancy intention among white women. Adjustment for individual socioeconomic factors did not appreciably influence the association between pregnancy intention and preterm birth among immigrant Latina women (Table 4). However, adjustments for maternal education, paternal education, age, marital status and parity made significant contributions to variation inpretermbirth risk, according to the log-likelihood ratio tests. After adjustment for all socioeconomic factors simultaneously, immigrant Latina women who reported being unsure about their pregnancy remained at an increased risk of preterm birth (odds ratio, 1.5).