TNF and chorioamnionitis: Interestingly, we noted that the MMP‐8 cut‐off for FIRS was similar to that for histologic chorioamnionitis (MMP‐8: 170.76 vs. 172.53 ng/ml, respectively), as reported previously,12 although the TNF‐α cut‐off was four‐fold higher for FIRS than for histologic chorioamnionitis (TNF‐α: 89.20 vs. 21.17 pg/ml, respectively).