What Happens to Cervical Mucus After IUI?

Cervical mucus plays a pivotal role throughout the conception process. The consistency and amount of mucus changes during the menstrual cycle and during and after conception. Infertile couples may choose intrauterine insemination (IUI) to increase their chances of conception. Cervical mucus after IUI may play a role in the process of conception.
IUI is an option for couples who experience trouble conceiving, couples in same-sex relationships, and single women who wish to become pregnant. The process involves the insertion of sperm through a catheter, directly into the endometrial cavity. The sperm, from either a donor or partner, is separated from the semen, leaving only motile sperm, and is inserted during ovulation. Cervical insemination, where the sperm is deposited in the cervix, is not used as commonly, as the success rate is lower. In some circumstances, however, it is still used when the sperm count is normal, such as in cases of donor sperm.

The cervical mucus goes through a number of phases during the normal menstrual cycle. At the beginning of the cycle there is minimal mucus and it is very cellular, creating a net-like structure that, generally, may prevent sperm from passing through. During the follicular phase, before ovulation, the cervical mucus levels increase and reach a maximum a day or two before ovulation. The mucus is more watery and salty, and forms little canals along which sperm can travel.

The consistency and make-up of cervical mucus can be influenced by a number of factors. Hormonal levels, such as low estrogen levels, may decrease cervical mucus. Some drugs, such as clomiphene citrate, which is commonly used for infertility, may have the same effect. When cervical mucus seems to be a factor in fertility, various treatment options may be tried, or an IUI directly into the uterus can be used.

Cervical mucus after IUI will depend on whether the insemination was successful and conception occurred. During pregnancy cervical mucus can increase and decrease according to the normal hormonal surges associated with pregnancy. At implantation, which occurs at about 14 days after conception, the cervical mucus discharge may be slightly blood-stained due to the physical implantation of the egg into the lining of the uterus. On the other hand, cervical mucus after IUI, if it is unsuccessful, will return to the normal phases.

Within the first few weeks of pregnancy, the cervical mucus will form the mucus plug. This forms a barrier to bacteria between the cervix and uterus, in the cervical passage. This plug is expelled close to labor, either as a plug or as increased discharge. While the consistency of cervical mucus after IUI may be an indicator of the success or failure of the procedure, a pregnancy test or hormonal test is far more reliable.