Clinical evaluation in vivo and in vitro of cervical mucus in IUD users: differences between women wearing copper and progesterone releasing IUDs

Abstract

This is a report of the variations of cervical mucus of women wearing different kinds of IUDs, before and after the insertion. We could not find significant variations of the clinical patterns in women wearing copper IUDs, but noticeable variations were found in progesterone releasing device users.

PIP: Modifications of cervical mucus associated with IUD use were investigated in 5 women fitted with a copper IUD and 5 women with a progesterone-releasing device. Also investigated was the survival and viability of sperm in users of these 2 types of IUDs. Mucus was collected from study subjects before IUD insertion and 3 months after insertion; the quantity, spinnbarkheit, cellularity, and ferning capacity were assessed. A capillary tube test was also performed, and penetration depth, penetration density, motility duration, and migration reduction were evaluated. Women with a copper IUD in place showed no significant changes in cervical mucus measures after insertion. In contrast, insertion of the progesterone-releasing device significantly modified the spinnbarkheit and the cellularity of the mucus, with a dramatic increase of leukocyes. Similarly, although the copper IUD did not produce significant variations in penetration test parameters, insertion of the progesterone-releasing IUD was associated with a significant decrease in sperm concentrations penetrated at 1 cm, a marked drop in sperm motility and survival, and a significant decrease in the reduction of migration. These results indicate that progesterone-releasing IUDs produce important changes in cervical mucus and reduce sperm penetration and survival. It is hypothesized that the negative effect on the cervical mucus may be a principal mechanism of action of the progesterone-releasing contraceptive device.