How does the HSG increase fertility?

1) It may effect a mechanical lavage of the tubes, dislodging mucus plugs.
2) It may straighten the tubes and thus break down peritoneal adhesions.
3) It may provide a stimulatory effect for the cilia of the tube.
4) It may improve cervical mucus.
5) The iodine may exert a bacteriostatic effect on the mucous membranes .
6) Ethiodol decreases in vitro phagocytosis by peritoneal macrophages. If the same effect occurs in vive it could decrease macrophage activity and thus aid fertility by inhibiting the release of cytokines and decreasing phagocytosis of sperm.

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