Phototherapy and plasma immunoreactive prostaglandin A values. Its effect in premature infants.

Plasma immunoreactive prostaglandin A (iPGA) values were determined for 14 premature infants before and after 48 hours of phototherapy and in a control group of six age-matched premature infants. At 4 to 8 days of life, the infants who had received phototherapy for 48 hours had significantly lower iPGA values compared with controls. At 2 to 3 days of life, four infants with a clinically apparent patent ductus arteriosus were found to have significantly elevated iPGA values compared with controls. After 48 hours of phototherapy, these infants likewise had a significant decrease in iPGA values compared with controls; in all four infants, the ductus closed spontaneously. Phototherapy is an effective method for decreasing plasma iPGA values in premature infants.