Abnormal cervical mucus may impair fertility by inhibiting penetration or increasing destruction of sperm.
(See also Overview of Infertility.)
Normally, cervical mucus is stimulated to change from thick and impenetrable to thin and stretchable by an increase in estradiol levels during the follicular phase of the menstrual cycle.
Abnormal cervical mucus may
- Remain impenetrable to sperm around the time of ovulation
- Promote sperm destruction by facilitating influx of vaginal bacteria (eg, due to cervicitis)
- Contain antibodies to sperm (rarely)
- Examination to check for cervicitis and cervical stenosis
A pelvic examination is done to check for cervicitis and cervical stenosis. Cervicitis is diagnosed if women have cervical exudate (purulent or mucopurulent) or cervical friability. Complete cervical stenosis is diagnosed if a 1- to 2-mm diameter probe cannot be passed into the uterine cavity.
Postcoital testing of cervical mucus to determine whether viable sperm are present (which used to be routine during infertility evaluation) is no longer considered useful because results do not correlate with subsequent pregnancy rates.
- Assisted reproductive techniques (intrauterine insemination or in vitro fertilization)
Treatment may include intrauterine insemination and in vitro fertilization. However, whether either treatment is effective in women with abnormal cervical mucus is unproved.
There is no evidence that using drugs to thin the mucus (eg, guaifenesin) improves fertility.
- Abnormal mucus rarely impairs fertility significantly, except in women with chronic cervicitis or cervical stenosis due to prior treatment for cervical intraepithelial neoplasia.
- Do a pelvic examination to check for cervicitis and cervical stenosis.
- Postcoital testing of cervical mucus is no longer considered useful.
- Consider intrauterine insemination and in vitro fertilization, but whether either results in pregnancy when cervical mucus is abnormal is unproved.