"Figure 6: Singleton and Multiple Infant Mortality Rates by Age of Mother and Grouped Gestation, 2006-2011 Birth Cohorts, England and Wales","" "","" "","" "Notes","1. Pre-term is 24 to 36 completed weeks; term is 37 to 41 completed weeks. 2. Infant mortality rates per 1,000 live births. 3. Known gestational age only." "Unit","Infant mortality rate per 1,000 live births" "","" "","Singleton, pre-term","Singleton, term","Multiple, pre-term","Multiple, term" "Under 20","34.5","2.6","50.9","5.2" "20-24","31.0","2.0","34.8","4.3" "25-29","26.6","1.6","24.7","2.9" "30-34","25.4","1.4","22.3","2.2" "35-39","25.1","1.4","20.6","2.5" "40+","27.9","2.2","22.3","2.2"