Comparison of MMP-3, MMP-9, TIMPs levels and MMP:TIMPs ratios in maternal serum among groups.

<p>Results are expressed as median (interquartile range) (ng/ml), group differences were evaluated with the Mann-Whitney <i>U</i>-test.</p><p>PTB, preterm birth; PT, preterm; AT, at term; NS, not significant.</p>$<p>Unadjusted P values and Bonferroni-adjusted P values (adjusted for 11 tests) between brackets.