NT-proBNP is increased in healthy pregnancies compared to non-pregnant controls.

Serum concentrations of the amino-terminal pro-B-type natriuretic peptide (NT-proBNP) may be used to monitor cardiac function during pregnancy but normal values are not established for this purpose. Therefore, we investigated NT-proBNP in normotensive healthy pregnancies compared to a non-pregnant control group. Serum NT-proBNP was measured in 94 normotensive, healthy pregnant women (32+/-6 years) every five weeks beginning from 12th gestational week (GW) in a longitudinal study and compared to a non-pregnant control group of 521 women (32+/-7 years). Pooled median serum NT-proBNP levels (25th; 75th percentile) were significantly higher in pregnant women compared to non-pregnant women (56 (33; 95) pg/ml vs. 38 (22; 62) pg/ml (p<0.001)). NT-proBNP increased during pregnancy to 73 (51; 124) pg/ml in the 11+6 to 15+6 GW (p<0.001). However, NT-proBNP levels from 23+0 GW towards term were comparable to non-pregnant controls. NT-proBNP is significantly elevated in healthy pregnancies until mid-pregnancy. As preeclampsia and gestational hypertension are associated with increased NT-proBNP, our results have to be considered in future diagnostic approaches using NT-proBNP for these pathologic conditions.