Efficacy of pharmacologic closure of patent ductus arteriosus in small-for-gestational-age extremely preterm infants

Background Optimal management of the patent ductus arteriosus (PDA) in preterm infants remains controversial. Therefore, studies identifying infants who are most likely to benefit from PDA treatment are needed. Aim We sought to examine if significant intrauterine growth restriction, defined by birth weight z-score, reduces the efficacy of PDA closure with indomethacin or ibuprofen and thereby increases the need for surgical closure of PDA after pharmacologic treatment. Study design, subjects, and outcome measures We studied infants 23–28 weeks' gestation born 2006–2013 at NICHD Neonatal Research Network centers. We examined the responses to PDA treatment with indomethacin and/or ibuprofen and whether the PDA was subsequently closed surgically. Logistic regression generated adjusted odds ratios (ORs) for the associations between the z-score groups (<− 2, − 2 to − 0.5, and >− 0.5) and PDA surgery following pharmacologic treatment. Results 5606 infants were diagnosed with PDA; 3587 (64.0%) received indomethacin or ibuprofen or both, and 909 (25.3%) underwent PDA surgery. Mothers of infants with PDA non-closure were less likely to have hypertension (19% vs. 28%). Infants with non-closure were more likely to be female (53% vs. 49%), have lower gestational age and birth weight and to develop sepsis (42% vs. 31%). Compared to infants with z-score > − 0.5, PDA surgery was increased among infants with z-score − 2 to − 0.5 (OR = 1.23; 95% CI 1.02–1.47) but not among infants with z-score < − 2. Conclusion Infants with birth weight z-score − 2 to − 0.5 are more likely than normally grown infants to require PDA surgery following pharmacologic treatment.