OBJECTIVE: To study the epidemiology of births in urban China.MethodsA retrospective study was conducted on neonates born in 2005 in the maternity departments of 72 urban hospitals from 22 provinces in China. RESULTS: A total of 45722 infants born between January 1, 2005 and December 31, 2005 were enrolled. The male to female sex ratio was 1.13:1. Preterm births accounted for 8.1%. The incidence of very low birth weight infants was 0.7%. A total of 99.7% of mothers delivering at term had conceived naturally and 0.3% had experienced assisted reproduction. A total of 98.4% of mothers who delivered preterm had conceived naturally and 1.6% had experienced assisted reproduction. The proportion of vaginal deliveries was 50.8% compared to 49.2% delivered by cesarean sections. Many cesarean sections (38.1%) were due to social factors. Infants with an Apgar score≤7 at 1 minute accounted for 4.8%, and 1.6% of infants had an Apgar score≤7 at 5 minutes. Of all the infants included in the study, 7.14% were admitted to neonatal units for treatment. The death rate of all included infants was 0.74%. CONCLUSIONS: The proportion of preterm births was higher in 2005 than in 2002-2003. The proportion of cesarean section deliveries was much higher in urban China than in most other Asian countries and America.