Objective: To study the relationship between bone morphogenetic protein-2 (BMP-2) and premature rupture of membranes (PROM).
Methods: Ninety gravidas giving birth at 4 hospitals in Chongqing from January 2006 to January 2007 were selected and divided into 5 groups (18 in each): term labor group ( with intact membranes), term PROM group, preterm labor group (with intact membranes), preterm PROM (PPROM) group and control group (term pregnancy not in labor). The expression of BMP-2 in the chorioamniotic membranes of each group were detected by streptavidin-peroxidase methods and its relationship with PROM plus histological chorioamnionitis were analyzed.
Results: (1) BMP-2 was detected in the cytoplasm of epithelial and interstitial cells of membranes in each group. (2) BMP-2 expression in term labor group, term PROM group, preterm labor group and PPROM group were 0.0137 +/- 0.0094, 0.0269 +/- 0.0127, 0.0273 +/- 0.0145, 0.0456 +/- 0.0114, respectively, which higher than that of the control group 0.0060 +/- 0.0079 (P < 0.01). BMP-2 expression in the term PROM group was higher than that of the term labor group (P < 0.01), that in the PPROM was higher than in the preterm labor group and term PROM group (P < 0.01). (3) Pathological examination found that 17 out of the 90 women with histologic chorioamnionitis, of which 13 (36%) came from the term PROM and PPROM group with a higher level of BMP-2 expression than those without chorioamnionitis (0.0201 +/- 0.0107 vs 0.0105 +/- 0.0092, P < 0.05).
Conclusion: The expression of BMP-2 in chorioamniotic membranes is closely related to PROM.