BNP concentrations and cardiovascular adaptation in preterm and fullterm newborn infants.

To evaluate and compare cardiovascular adaptation of 36 preterm and 34 fullterm newborns, we analyzed BNP concentration and echocardiographic parameters at day 3 of life and at day 28 (+/-2). On day 3 BNP concentrations (pg/ml) resulted higher in PDA preterm group (n=11; 125, IQR 56.1-301) than preterm without PDA (n=25; 25.5 IQR 10.9-49; p<0.001) than fullterms (n=34; 55.1 IQR 23.6-82.7; p=0.013). No difference resulted in all groups at 28days (respectively: 12.7 IQR 4.9-23.8; 15.6 IQR 10-22; 8.9 IQR 5.6-20.6). Because of the newborns' growth, all echocardiographic parameters increased with linear relationship with body weight. On day 3 BNP concentration and echocardiographic parameters were not correlated besides LA/AO in preterms with PDA (p=0.0015). On day 28, BNP was significantly correlated with mVTI (p=0.019), M (p=0.007) and LA (p=0.005) in fullterms and only with LA (p=0.007) in preterms. In conclusion, BNP concentrations and echocardiographic measures confirm that preterm, and fullterm newborns conduct themselves in a similar manner during the transition from foetal to post-natal circulation, reaching low levels at a month of life. The presence of PDA during first days of life has no significant impact in this adaptation. LA is the echocardiographic parameter mostly related to BNP concentration in the newborns.