Background and Aims Impairment of gas exchange and blood flow through the placenta leads to hypoxia and hypercapnia. This causes increased systemic vascular resistance and tachycardia, thus compromising the cardiovascular system of the foetus. The biomarker B-type natriuretic peptide (BNP) can be used to identify significant cardiovascular compromise in infants. The aim of the present study was to investigate whether BNP can be used to identify those preterm infants with significant cardiovascular compromise during peripartum period.
Methods In this retrospective cohort study all infants born after a gestational age of less than 32 weeks were evaluated. Maternal, fetal and infant factors associated with prenatal and perinatal hypoxia-ischemia were related to BNP levels after birth. Pathologic examination of the placenta was routinely performed.
Results In total 164 infants were evaluated. Infants with increased placental ischemia and a higher placental maturation score had elevated levels of BNP at birth (r² 0.12; p<0.001). Furthermore BNP was found to be associated with (chronic) prenatal hypoxia-ischemia (nucleated red blood cells (r² 0.22; p<0.001); intrauterine growth retardation (r² 0.18; p<0.01); postnatal thrombocytopenia), and acute perinatal hypoxia (umbilical artery pH (r² 0.14; p<0.001); serum lactate (r² 0.11; p<0.001).
Conclusion Elevated BNP levels after birth are found in those preterm infants with significant perinatal hypoxia-ischemia and are possibly related to placental dysfunction. If BNP levels are related to prenatal signs of circulatory compromise needs further investigation.