Elevated Infant Mortality Rates among Oral Cleft and Isolated Oral Cleft Cases: A Meta-Analysis of Studies from 1943 to 2010

Abstract

Objective To review available published literature in order to obtain a more comprehensive assessment of the association between infant mortality and oral clefts, overall and isolated. Design A wide-ranging search of published studies relating infant mortality rates to oral clefts and congenital malformations was conducted, yielding applicable data sets. Settings of the included studies varied to a limited extent, although all were conducted within high-income countries with superior health indicators. These results were tabulated and meta-analyzed. Random effects odds ratios comparing each data set with its respective population have been used to account for differing settings and specific infant mortality rates. Results Nine articles with relatable data were included in these meta-analyses. The calculated odds ratio of infant mortality associated with oral cleft cases, including those with associated malformations, was substantial: 9.466 (95% confidence interval, 6.153 to 14.560). Excluding oral cleft cases with associated malformations, the odds ratio, although lower, was still significant: 2.073 (95% confidence interval, 1.390 to 3.092). Conclusions Compared with the overall population, infants with oral clefts have nine times the odds of dying within the first year of life. Furthermore, even without additional malformations, infants with oral clefts are still twice as likely to die before 1 year of age. Current research points to a substantially higher relative risk of infant mortality among oral cleft cases in developing countries. Additional research is essential to determine the sources of these raised infant mortality rates and possible interventions to decrease them.