Parental age as a risk factor for non-syndromic oral clefts: a meta-analysis

A meta-analysis was conducted to assess the relationship between parental age and the occurrence of non-syndromic oral clefts. The questions addressed if younger or older mothers and fathers have an increased risk of having a child with non-syndromic oral clefts.

Data from cohort studies, case-control, cross-sectional and prevalence studies in which the association between parental age and oral clefts was investigated were analysed. Only studies on oral clefts not associated with syndromes or other anomalies were considered.

An electronic literature search were conducted in Medline, Embase, LILACS, SciELO, SCOPUS and the Cochrane library databases to identify original research published until November 2010. References of the selected articles were also searched.

The initial database search identified 4623 citations and according to eligibility criteria 80 articles were submitted to quality assessment. In 13 studies measures of association could be extracted for meta-analysis.

Our findings suggest that fathers forty years of age or older had a 58% higher probability of having a child with cleft palate compared to those aged between 20 and 39 years. The probability of mothers aged between 35 and 39 years having a child with cleft palate was 20% higher in comparison with those between 20 and 29 years-old, whilst for those aged 40 years or more this probability was 28% higher compared to those aged between 20 and 29 years. Mothers aged 40 years or over were 1.56 times more likely to have a newborn with cleft lip with or without palate compared to those aged between 20 and 29 years. No evidence of association between early maternal and paternal age with occurrence of oral clefts was observed.