Short birth interval predicts the risk of preterm birth among pregnant women in Sub-Saharan Africa: A systematic review and meta-analysis

Abstract Background: World health organization recommends that women wait at least 2 years after a live birth to reduce the risk of adverse birth outcomes, like preterm birth, in the subsequent pregnancy. However, studies have reported inconsistent finding regarding short birth interval as risk factor for preterm birth. Therefore, the aim of this systematic review and meta-analysis is to summarize and estimate the pooled effect of short birth interval on preterm birth among pregnant women with previous live birth.Methods: The search strategy aimed to find both published and unpublished studies. The search was conducted from MEDLINE/PubMed, EMBASE, CINAHL, Web of science, MedNar, Google, Google scholar and African Journals online (AJOL). Observational studies which reported the association between short birth interval and preterm birth were included. The methodological quality of selected papers was assessed by two independent individuals prior to their inclusion in the review using standardized Joanna Briggs Institute (JBI) quality assessment tools. The analysis was done using RevMan software. A random effect meta-analysis was used to estimate the pooled effect with a 95% confidence interval. Forest plot was used to visualize the presence of heterogeneity. Funnel plot was used to check for publication bias.Results: From a total of 234 published and unpublished studies identified, 10 studies that were conducted from 2015 to 2019 in Sub-Saharan African countries were included in the analysis. The meta-analysis result showed that Short birth interval had significant effect on preterm birth. The odds of having preterm birth was 2.21 times higher (OR = 2.21, 95% CI = 1.53, 3.21) among pregnant women with short (less than 2 years) birth interval compared to their counter parts. The sub-group analysis showed that the case-control studies showed statistically significant association between short birth interval and preterm birth, but not the cohort studies.Conclusion: Based on our review findings we may recommend that health planner or clinical practitioners should counsel or educate women, considering the health and economic consequence of premature birth, to increase birth interval to at least two years.