MMP1 and pelvic organ prolapse: To investigate the associations between single nucleotide polymorphism (SNP) type 1G/2G at position −1607/−1608 of the matrix metalloproteinase (MMP)-1 gene and SNP type 5A/6A at position −1612/-1617 of the MMP-3 gene and the development of pelvic organ prolapse (POP) in women.