Since 1980, multiple birth ratios have increased dramatically (>50%), especially among higher order multiples (>400%). These increases have had noticeable impact on perinatal outcomes, including infant mortality. A retrospective analysis of vital statistics data from the National Center for Health Statistics was conducted to examine birthweight-specific infant mortality by plurality and maternal race in the United States. In 1998, the infant mortality rate (IMR) was higher among singletons than multiples for very low birthweight (VLBW, <1500g) infants (260.4 and 232.2 per 1,000, respectively, p< 0.001) and moderately low birthweight (1500-2499g) infants (18.7 and 8.5 per 1,000, respectively, p< 0.001); but lower among singletons than multiples for infants over 2500g (2.6 and 3.6 per 1,000, respectively, p<0.001). When dichotomized by race, a similar pattern is seen among white infants; however among VLBW black infants, there was no significant difference in rates by plurality. In the past decade, infant mortality has decreased more among multiples than singletons for all three birthweight categories. Among VLBW infants, the IMR decreased 23.6% among singletons and 33.8% among multiples. The differential rates of infant mortality for singletons and multiples suggest disparities in the management and risk factors for these pregnancies.
Learning Objectives: At the conclusion of the session, participants in this session will be able to: 1. Describe the differences in infant mortality by birthweight categories and how these have changed over the past decade. 2. Assess the impact of multiple births on the birthweight-specific infant mortality rates. 3. Discuss the implications of the differential infant mortality rates on management and risk factors for these pregnancies.
Keywords: Infant Mortality,
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.