The extent of pregnancy mistiming and its association with maternal characteristics and behaviors and pregnancy outcomes.

CONTEXT The National Survey of Family Growth (NSFG) classifies pregnancies as intended, mistimed or unwanted. However, these categories could be too broad, as a woman's feelings about a pregnancy, her health behaviors during pregnancy and thus her pregnancy outcomes may vary according to whether her pregnancy is moderately or seriously mistimed. These relationships have not yet been explored. METHODS Data from the 1995 NSFG were examined to assess associations between pregnancy mistiming and maternal characteristics. Descriptive and multivariate analyses were conducted of the extent of mistiming for each maternal characteristic. Chi-square and F-tests were used to examine the associations between a pregnancy's intendedness--according to a four-category classification--and maternal characteristics, maternal happiness ratings, maternal behaviors and pregnancy outcomes. RESULTS Fifty-five percent of mistimed pregnancies were mistimed by 24 months or less, 32% were mistimed by 25-60 months and 13% were mistimed by more than 60 months. According to multivariate analyses, pregnancies among younger women, never-married women and black women were mistimed by significantly more months than those among other women. The distribution of moderately mistimed pregnancies differed significantly from those of both seriously mistimed and unwanted pregnancies according to most maternal characteristics; there were few differences between intended and moderately mistimed pregnancies, and between seriously mistimed and unwanted pregnancies. CONCLUSIONS Mistiming is not a unitary construct. Its extent is associated with maternal characteristics and behaviors. Future research on pregnancy intention should examine the extent of mistiming and consider alternatives to traditional definitions of intendedness.