In the U.S. demographic factors are associated with birth outcomes, although biological mechanisms are not clear. The authors examined whether conception interval length might explain some demographic risk markers for infant low birthweight, preterm, and survival using Minnesota’s 1990-1996 linked birth-death files. Multivariate analyses were conducted separately for 4866 adolescent and 210,108 adult multiparae. The mean conception interval length was 13 months for adolescents and 32 months for adults. Short interval length for adolescents was highest among those who were married and those with inadequate educations. Adolescent interval length was positively associated with birthweight (p=.009), but was not associated with other infant outcomes. For adults, short interval length was associated with younger age, married status and poor educational attainment. While adult interval length was positively associated with infant birthweight (p=.0001), low birthweight risk was highest among infants of women with either very short or long intervals. Interval length did not show clear patterns by maternal race for either age group. The stronger association of interval length to birth outcomes for adults could be because adolescent multiparae have little variation in interval length or because interval length has different influences for women of different ages. While it is often thought that interval length is not relevant to birth outcomes in well-nourished populations, the demographic patterns of short and long intervals in this study, as well as the association of intervals to some birth outcomes, suggest that interval length could signal factors other than nutrition in the U.S.
Learning Objectives: At the conclusion of the session, the participant will be able to: 1. Identify the association between conception interval length and infant birthweight and gestational age at birth. 2. Articulate differences in the distribution of interval length by maternal demographic factors for adolescents and adults.
Keywords: Birth Outcomes, Family Planning
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
Disclosure not received
Relationship: Not Received.