Figure 2.

Major malformation prevalence per 1000 foetuses/infants per year using different inclusion criteria for livebirth records. Data sources included the Birth register, children and maternal records from the Patient register, the Abortion register, and the Cause of Death register. All records included any type of diagnosis; primary/secondary records included discharge or outpatient diagnoses, tentative diagnoses were excluded; primary/secondary records, major hip records (minimum 2 records), added a further restriction of minimum 2 records for major hip records; primary/secondary records, major hip records (>6 weeks postpartum), included primary/secondary records added a further restriction of diagnose after 6 weeks postpartum for major hip malformations; primary/secondary records by specialist, major hip records (>6 weeks postpartum), included primary and secondary diagnoses by an obstetrician or paediatrician, added a restriction of diagnoses after 6 weeks postpartum for major hip malformations.