Platelet Counts in the First Seven Days of Life and Patent Ductus Arteriosus in Preterm Very Low-Birth-Weight Infants

Abstract

Background: Decreased platelet number and/or function are related to patent ductus arteriosus (PDA) in mice. Whether this is also the case in human infants remains controversial. Objectives: To investigate the association between platelet count nadir within the first 7 days of life and the rate of hemodynamically significant PDA (HSPDA), as well as the rate of response to the treatment with cyclooxygenase (COX) inhibitors. Methods: This is a retrospective study of a cohort of 194 very low-birth-weight (VLBW) infants (<1,500 g) with gestational age <30 weeks. HSPDA was assessed by echocardiography on day 3 of life. Results: HSPDA was present in 105 infants (54.1%). Of these, 101 were treated with COX inhibitors. The treatment failure rate was 21.8%. Median platelet count nadir and rate of thrombocytopenia - defined as platelet count <150 x 10(9)/l and graded as mild (100 to <150 x 10(9)/l), moderate (50 to <100 x 10(9)/l) or severe (<50 x 10(9)/l) - within the first 2 days of life were not significantly associated with the presence of HSPDA on day 3. Moreover, low platelet counts, either on days 1-2 or 3-7, were not significantly associated with the rate of response to treatment with COX inhibitors. Conclusions: Our data provide further evidence for the lack of association between platelet counts within the first days of life and either spontaneous or pharmacological closure of the ductus arteriosus in VLBW infants.