The percentages of NLRP3‐positive macrophages (50.73 ± 0.51% in the PPROM group and 44.89 ± 0.41% in the PROM group), ASC‐positive macrophages (41.80 ± 0.68% in the PPROM group and 34.65 ± 0.34% in the PROM group), and caspase‐1‐positive macrophages (53.08 ± 0.51% in the PPROM group and 43.99 ± 0.43% in the PROM group) in the PPROM group and the TPROM group were significantly higher than in the control group (NLRP3: 39.30 ± 0.46%, ASC: 32.05 ± 0.26%, caspase‐1: 33.06 ± 0.51%), and the difference was statistically significant (p < .05). This evidence concerns the gene NLRP3 and preterm premature rupture of the membranes.