To investigate the predictive value of serum B-type natriuretic peptide (BNP) to meconium aspiration syndrome (MAS) with persistent pulmonary hypertension of the newborn (PPHN).

It was a prospective cohort study, 86 infants were enrolled in the NICU from January 2017 to March 2019. Infants of MAS were classified into the PPHN group (n=26) and non-PPHN group (n=60), all infants were collected data in perinatal period. Serum BNP levels were detected in the 24-48 hours after birth. When the condition of the MAS infants was aggravated, serum BNP levels, blood gas analysis, chest X-ray and echocardiography were detected. BNP levels and OI, A-aDO₂ were compared between PPHN group and non-PPHN group.

BNP levels in PPHN group [1 049.87(787.95, 1 484.50)ng/L] were significantly different with those in non-PPHN group [344.15(302.75, 510.25)ng/L] in the 24-48 hours after birth(U=68.50, P<0.01). In the infants with PPHN, significantly higher increases were found in BNP levels [1 435.45(986.50, 1 869.20)ng/L] and A-aDO₂ [(535.72±82.128)mmHg] compared with those in non-PPHN group [632.54(479.35, 867.23)ng/L, (388.75±78.78)mmHg] when the condition was aggravated (U=57.75, t=5.83, all P<0.01). But there was no significant difference in OI (20.38±3.88, 21.62±4.86) between the two groups (t=0.86, P>0.05). ROC curve was used to analyze the diagnostic efficacy of BNP level for PPHN combined with MAS. The area under the curve was 0.956 (95%CI: 0.889~0.989). The optimum threshold BNP level was 652 ng/L, the sensitivity of predicting PPHN was 88.46%, and the specificity was 95.00%.

In the MAS infant, BNP had excellent sensitivity and specificity in predicting PPHN, which maybe a useful early diagnosis biomarker.