A short interpregnancy interval is a risk factor for preterm birth and its recurrence
Presented at the 27th Annual Clinical Meeting of the Society for Maternal–Fetal Medicine, San Francisco, CA, Feb. 5-10, 2007.
Objective
We tested the hypothesis that short interpregnancy intervals (IPIs) increase the risk for preterm birth (PTB), recurrence of PTB, and delivery at early extremes of gestational age.
Study Design
Using the Missouri Department of Health’s birth certificate database, we performed a population-based cohort study of 156,330 women who had 2 births from 1989-1997. The association between IPI and subsequent pregnancy outcome was assessed.
Results
The shortest IPIs (<6 months) increased the risk of extreme PTB (adjusted odds ratio, 1.41; 95% CI, 1.13-1.76). IPIs of <6 months and 6-12 months increased the overall risk of PTB (adjusted odds ratios, 1.48 [95% CI, 1.37-1.61] and 1.14 [95% CI, 1.06-1.23], respectively) and PTB recurrence (adjusted odds ratios, 1.44 [95% CI, 1.19-1.75] and 1.24 [95% CI, 1.02-1.50], respectively).
Conclusion
The risk of PTB and its recurrence increases with short IPIs, even after adjustment for coexisting risk factors. This highlights the importance of counseling women with either an initial term or preterm birth to wait at least 12 months between delivery and subsequent conception.
aDepartment of Obstetrics and Gynecology and the Center for Preterm Birth Research, Washington University School of Medicine, St. Louis, MO
bDepartment of Pediatrics, Washington University School of Medicine, St. Louis, MO.
Reprints: Emily DeFranco, DO, Washington University School of Medicine, Department of Obstetrics and Gynecology, 4566 Scott Ave, Campus Box 8064, St. Louis, Missouri 63110
Supported by a grant from the March of Dimes.
Cite this article as: DeFranco EA, Stamilio DM, Boslaugh SE, Gross GA, Muglia LJ. A short interpregnancy interval is a risk factor for preterm birth and its recurrence. Am J Obstet Gynecol 2007;197:264.e1-264.e6.
The results, interpretations, and conclusions included in this manuscript are those of the authors and not of the Section of Public Health Practice and Administrative Support, Missouri Department of Health and Senior Services, which maintains the maternally linked birth certificate database from which the data studied for this analysis were derived.
ABSTRACT