What Does Hostile Uterus Mean?
A hostile uterus is an outdated term used to describe either insufficient or poor-quality cervical mucus that is unfriendly to the movement of sperm.
As a result, sperm loses the ability to travel through a woman’s cervix and is likely to die prior to reaching the fallopian tube to fertilize an egg.
So-called hostile cervical mucus is not ideal for facilitating pregnancy and is a cause of subfertility.
A hostile uterus may also be called cervical hostility. Because the cervix is the lower part of the uterus, the two terms have been used interchangeably to describe this condition.
FertilitySmarts Explains Hostile Uterus
For fertilization to occur, there needs to be an egg, a sperm, and the ability for the two to meet. Cervical mucus is a fluid that plays an important role in bringing the sperm and egg together inside the female reproductive tract.
The Role of Cervical Mucus
The consistency of the cervical mucus changes throughout the menstrual cycle. It can roughly be described as non-peak mucus that is somewhat fertile and peak mucus that is considered to be the most fertile.
Because the vagina is inhospitable to sperm in its natural state, the body needs to alter the pH of the vagina in the days leading up to ovulation in order to support sperm survival and transport. This is done by creating fertile-quality cervical mucus that can support sperm for up to 5 days in the female reproductive tract.
As ovulation approaches, estrogen levels peak and cause the cervical mucus to attain a watery, raw egg white-like consistency, providing a receptive environment for sperm into the cervix and up towards the rest of the reproductive tract.
However, after ovulation, the cervical mucus becomes non-fertile with a thick and creamy consistency that helps block the entry of sperm into the cervix. This period is known as non-peak cervical mucus.
Sometimes, regardless of the stage of the menstrual cycle, the consistency of the cervix can change and prevent the normal fluidity of the cervical mucus. This can prevent the entry of the sperm or even destroy it.
What causes a “hostile” uterus?”
A few of these factors are as follows:
- Hormonal imbalances. Especially low estrogen states, such as premature ovarian failure, anorexia nervosa, or use of medications
- Reduced pH of cervical mucus. Sperm prefer an alkaline environment to survive with ranges between 7.0 to 8.5; certain infections like bacterial vaginosis, can increase the acidity of the cervical mucus and contribute to cervical hostility.
- The presence of inflammatory cells in the cervix (cervicitis). A vaginal or cervical infection thickens the cervical mucus.
- The presence of an anti-sperm antibody. An immune protein (antibody) directed against the sperm can coat the cervical mucus, attacking the sperm and interfering with the capability of a woman to get pregnant.
- Genetics. Conditions like cystic fibrosis can impact cervical mucus.
- Use of medication. Like gonadotropin-releasing hormone agonists, clomiphene citrate, and aromatase inhibitors.
- Lifestyle. Factors like smoking.
Treatment of cervical hostility varies with its cause. Intrauterine insemination (IUI) can be used to bypass the "hostile" cervical mucus. In this technique, a physician injects sperm directly into the uterus with a small tube passed through the cervix, bypassing the need for fertile cervical mucus.