Short Interpregnancy Intervals and the Risk of Adverse Birth Outcomes among Five Racial/Ethnic Groups in the United States

Data from the National Center for Health Statistics for over 4.8 million births for the period 1989-1991 are used to study the effects of short interpregnancy intervals on the risks for low birth weight and preterm delivery for singleton births in the United States. The focus is on differences among African American Mexican Native American non-Hispanic white and Puerto Rican mothers. Intervals of less than 6 months and between 6 and 12 months occurred with greatest frequency among Native Americans followed by Puerto Ricans African Americans Mexicans and non-Hispanic whites. "Our results suggest that the length of the interval between pregnancies has a similar and substantial effect on the risk of low birth weight and preterm delivery among five major racial/ethnic groups of mothers in the United States." (EXCERPT)