Relationship between spontaneous ductus arterosus closure and hemoglobin levels among very low birth weight infants

We have recruited 171 very low birthweight and/or very premature newborns who have been born in Trakya University School of Medicine Hospital subsequently admitted to our Neonatal Intensive Care Unit between January 2017 and August 2023 to investigate possible relation between spontaneous closure of ductus arteriosus and 24th and 72nd hour hemoglobin levels. Twenty fourth and 72nd hour hemoglobin levels and doppler echocardiography images have been obtained from our study group of 171 newborns and consecutively analyzed retrospectively. 171 newborns have been separated to 5 different sub-study groups accordingly to their doppler echocardiography findings regarding situtation of ductus arteriosus as closed (Group 1), spontaneously closing (Group 2), spontaneously opening (Group 3), open despite treatment (Group 4) and closed by treatment (Group 5). Groups have been compared to each other by their individual prenatal, antenatal, postnatal, demographic characteristics and additionally by neonatal morbidities, duration of hospital stay and mortality rates and by erythrocytic serie values. We have found statistically significant relation between 24th and 72nd hour hemoglobin levels and spontaneous closure of ductus in our study cohort consisting of 171 very preterm and/or very low birth weight infants. Newborns who had their ductus closed on both 24th and 72nd hour doppler echocardiographic asssesment and who had open ductus at 24th hour but closed without treatment at 72nd hour, had significantly higher levels of hemoglobin compared to other groups at respective hours. Our study has also shown that when Hb levels at 24th hour reaches 16,05 mg/dl or above, odds of spontaneous closure of DA also 2.28 times more likely with sensitivity %60,30 and specifity %60. Similarly it has also shown when 72nd hour Hb levels reaches 14,2 mg/dl or above, odds of spontaneous closure of DA also increases 3.20 times with %64,70 sensitivity and %60 specifity and specifically relevant to 72nd hour Hb levels, every 1 mg/dl increase of this parameter makes spontaneous closure of DA 1.29 times more likely. When gestational week reaches before delivery to 27,5 weeks or above odds of spontaneous closure of DA increases 6.99 fold with %74.10 sensitivity and %71 specifity and with every extra week in utero also increases the likelihood of spontaneous closure of DA by 1.39 fold. Finally, although we have spotted a statistically significant correlation between hemoglobin levels and spontenous closure of ductus arteriosus, there are not enough studies supporting our findings. It's imperative to emphasize that prospective and more comprehensive studies with larger cohorts are required to further improve on these results. Key words: Patent Ductus Arteriosus, Hemoglobin, preterm, newborn, spontaneous closure