A new approach to an old hypothesis; phototherapy does not affect ductal patency via PGE₂ and PGI₂

Abstract

Objective: Numerous investigations have demonstrated that phototherapy (PT) directly or indirectly causes ductal patency by photorelaxation effect. In this observational study, we aimed to assess the effect of PT on the incidence of patent ductus arteriosus (PDA) together with prostaglandins (PGE2) and (PGI2) levels in preterm infants.

Methods: Preterm infants whose gestational age < 34 weeks and who required PT in the first 3 d of life were enrolled in this prospective study. The clinical signs of PDA, the data of detailed echocardiographic study were recorded and plasma PGE₂ and PGI₂ levels were measured before and after PT. The outcome measures were the status of ductus arteriosus and alterations of PGE₂ and PGI₂ levels under the effect of PT.

Results: A total of 44 preterm infants were enrolled in the study, of these 21 (47.7%) were in Group 1 (Non-PDA Group) and 23 (52.3%) were in Group 2 (PDA Group). After PT, ductal reopening occurred in three infants (14.3%) in Group 1, while ductus closed in four infants in Group 2 (17.3%). PT does not seem to effect ductal patency for both groups (p = 0.250 and p = 0.125, respectively). PGE₂ levels were not different before and after PT for both groups (p = 0.087, p = 0.408, respectively). However, PGI₂ levels were significantly decreased after PT in both groups (p = 0.006, and p = 0.003, respectively).

Conclusion: There was no effect of PT on ductal patency. We can conclude that PGs were eliminated simultaneously with ductal closure and photorelaxation effect did not influence PG levels.

• Patent ductus arteriosus
• preterm infant
• phototherapy
• prostaglandin

Declaration of interest

All of the authors declared that they have no conflict of interests.