Risk factors of acquired prothrombin complex deficiency syndrome: a case-control study.

BACKGROUND Idiopathic vitamin K deficiency in infancy or acquired prothrombin complex deficiency (APCD) is a serious bleeding disorders in infants. It leads to a high mortality rate and permanent neurological sequele among the survivors. A low vitamin K intake by infants is suggested to have a major role in the pathogenesis. To reduce the incidence of this syndrome, its risk factors have to be identified. OBJECTIVE To determine the risk factors of the acquired prothrombin complex deficiency syndrome in the early infantile period. MATERIAL AND METHOD A case-control study was conducted in 20 cases and 60 age- and sex-matched controls who were admitted to the Queen Sirikit National Institute of Child Health in Bangkok during August 1991 to August 1993. Feeding type, maternal history of herb-liquor extracts (herbal medicine) use and no history of vitamin K1 prophylactics at birth were identified to be risk factors of the syndrome. All subjects were fed by breast milk with or without formula milk. None of the subjects fed by formula milk were in the case group (Chi-square for trend = 14.77, p = 0.001). RESULTS The rate of a maternal history of herb-liquor extracts use in the case group was significantly higher than that of the control group (p = 0.03). Vitamin K2MK4 level in breast milk obtained from the mothers of the infants with maternal history of herb-liquor extracts use was lower than that obtained from the mothers of the infants without maternal history of herb-liquor extracts use (p = 0.03). No infant with history of intramuscular K1 prophylactics was in the case group. Three out of eight infants with history of oral vitamin K1 regimen were cases. Although vitamin K1 and K2MK4 level in breast milk obtained from the cases' mothers were significantly lower than that obtained from the controls' mothers (p = 0.015 and p = 0.003 respectively), there was an overlapping of vitamin K levels among these two groups. CONCLUSION This study demonstrated that vitamin K in breast milk has a main role in the pathogenesis of this disease. Herb-liquor extracts may be a cause of the APCD syndrome. Intramuscular vitamin K1 prophylactics should be routinely given to all newborn babies who will receive breast feeding. Effectiveness of oral vitamin K1 prophylactics regimen must be studied urgently.