The impact of short interpregnancy intervals on pregnancy outcomes in a low-income population

The objective of this study was to determine whether the length of the interval between pregnancies was associated with either preterm birth or intrauterine growth retardation in a low-income, largely Black population.

The study population consisted of 4400 women who had received prenatal care in county clinics and had two consecutive singleton births between 1980 and 1990.

Interpregnancy intervals were positively associated with age and negatively associated with the trimester in which care was initiated in the second pregnancy. Whites had shorter intervals than non-Whites. The percentage of preterm births increased as the length of the interpregnancy interval decreased, but only for women who had not had a previous preterm birth. The association between interval and preterm birth was maintained when other factors associated with preterm birth were controlled. There was no significant relationship between intrauterine growth retardation and interpregnancy interval.

Women, particularly those who are poor and young, should be advised of the potential harm to their infants of short interpregnancy intervals.