OBJECTIVETo understand the incidence and relevant affecting factors of infant vitamin K deficiency bleeding (VKDB) in Shandong Province.

METHODSWith stratified cluster sampling, 28 156 live newborns from five districts and six counties were surveyed for the condition of bleeding from their birth to 6 months based on standard diagnostic criteria. A 1:2 matched case-control study of VKDB was performed.

RESULTSAn overall incidence of VKDB was 3.27 per thousand in Shandong; higher in the rural areas (4.96 per thousand ) than in the urban areas (1.19 per thousand ). Most of the bleeding cases were breast-fed babies (about 95.57%) and incidence of VKDB in pre-term babies (22.52 per thousand ) was higher than that in term ones (2.96 per thousand ). Mothers' drug taking during pregnancy, asphyxia at birth, breast-feeding and illness within two weeks after birth were risk factors for it. Use of vitamin K after birth and bottle-feeding were protective factors for it.

CONCLUSIONSIncidence of VKDB is higher in Shandong Province, as compared to other areas all over the country at the same time period. It is very important to prevent VKDB, focusing on high-risk babies in the rural areas, including those of preterm, breast-fed and suffering illness after birth.