Shorter birth intervals are associated with an increased risk of
premature births
Conclusion
Inter-pregnancy intervals shorter than 18 months and longer than 59 months are
significantly associated with increased risk of adverse perinatal outcomes including
premature births. Spacing pregnancies appropriately may prevent many of these preterm
births.
Clinical Question
Are shorter birth intervals associated with an increased risk of premature births?
Search Terms
Premature delivery, inter-pregnancy interval
Citation
Conde-Agudelo A, Rosas-Bermundez A, Kafury-Goeta AC. Birth Spacing and Risk of
Adverse Perinatal Outcomes A Meta-analysis. JAMA 2006:295; 1809-1823.
Object of Research
Birth spacing
Research Outcome
Premature birth
Study Features
This meta-analysis included cohort, cross-sectional, and case-control studies with results
adjusted for maternal age and socioeconomic status. Estimates of relative risk of birth
spacing and perinatal outcomes were made. Initially, 130 articles were identified in the
search with 67 (52%) included.
Evidence Grade: Level 2
The Evidence
Compared with inter-pregnancy intervals of 18 to 23 months, inter-pregnancy intervals
shorter than 6 months, 6 to 11 months and 12-17 months were associated with an
increased risks of preterm birth with pooled adjusted odds ratios and 95% confidence
intervals of 1.40 [95% CI: 1.24-1.58], 1.14 [95% CI: 1.10-1.17], and 1.07 [95% CI: 1.031.11], respectively. Inter-pregnancy intervals longer than 59 months were also associated
with a significantly greater risk for preterm births with an odds ratio=1.20 [1.17-1.24]
Appraised by: The Jordan Evidence-Based Medicine Reproductive Health Group
Update by: 4 July 2015