Trends in First Interpregnancy Interval among U.S Women

Casey E. Copen, National Center for Health Statistics (NCHS), CDC

Recent trends using the vital registration system indicate declining birth and pregnancy rates in the United States. To corroborate these data, the 1995, 2002 and 2006-2010 National Survey of Family Growth, are used to examine the inter-pregnancy interval (IPI) between first live birth and a second pregnancy leading to a live birth among Hispanic, Black and White women. IPIs are presented by when women first gave birth in 10-year groups to monitor a time trend. During this period, a pattern of lengthening IPI was evident: the time from first birth to second pregnancy increased from 29 months to 40 months. Multivariate models also suggest declines in the hazard of a second pregnancy leading to a live birth, although these patterns vary by Hispanic origin and race.