First-trimester maternal serum matrix metalloproteinase-9 (MMP-9) and adverse pregnancy outcome

To investigate the potential value of maternal serum matrix metalloproteinase-9 (MMP-9) in first-trimester screening for preeclampsia and spontaneous early preterm delivery.

The concentrations of MMP-9, tumour necrosis factor soluble receptor-1 (TNF-R1), pregnancy-associated plasma protein-A (PAPP-A) and uterine artery pulsatility index (UA-PI) were measured at 11(+0) - 13(+6) weeks in cases of preeclampsia (n = 128), gestational hypertension (n = 88), small for gestational age (n = 296), spontaneous early preterm delivery (n = 57) and controls (n = 569). The distributions of measured metabolites and UA-PI in the control and adverse outcome groups were compared. Logistic regression analysis was used to determine the significant contributors in the prediction of adverse outcomes.

The median MMP-9 was higher than controls in the preeclampsia (1.190 MoM) and preterm delivery (1.187 MoM) groups. In the preeclampsia group there was a significant association between serum MMP-9 and TNF-R1 (r = 0.523, P < 0.0001). Significant prediction of preeclampsia was provided by history and UA-PI, and prediction of preterm delivery was provided by history and neither was improved by the addition of MMP-9.

In pregnancies developing preeclampsia, the increased level of MMP-9 and the good correlation with TNF-R1 suggest the presence of an underlying inflammatory process. In the pregnancies resulting in spontaneous preterm delivery the small increase in MMP-9 is not useful in the prediction of preterm delivery.