A womb infection, or endometritis, is an inflammation or infection of the uterus’s inner lining. It occurs when microorganisms invade the uterine cavity, which is typically sterile. These infections can lead to various complications affecting reproductive health.
Types of Infectious Agents
Womb infections are primarily caused by bacteria. Sexually transmitted bacteria like Chlamydia trachomatis and Neisseria gonorrhoeae are common culprits. These bacteria can ascend from the lower genital tract, infecting the uterine lining. Other bacteria from the vaginal flora, including anaerobic bacteria, Escherichia coli, and Group B Streptococcus, can also contribute when the natural balance is disrupted.
While bacteria are the predominant cause, other microorganisms can also play a role. Fungi, particularly Candida species, are occasional causes, often in individuals with weakened immune systems. Viruses, such as Cytomegalovirus, are rarely direct causes of endometritis.
How Infections Enter the Womb
Infections most commonly enter the womb through an ascending pathway, traveling upwards from the vagina and cervix. The cervix normally acts as a protective barrier, aided by a mucus plug and the vagina’s acidic environment. When these natural defenses are compromised, bacteria from the lower genital tract can bypass the cervix and enter the uterine cavity.
Direct introduction is another pathway, often occurring during medical procedures. Instruments or substances introduced into the uterus can carry bacteria directly into the sterile environment. This bypasses natural protective barriers, creating an immediate entry point for pathogens.
Less commonly, infections can spread through the bloodstream, known as hematogenous spread. Bacteria from an infection elsewhere in the body can travel through blood vessels to reach uterine tissue. This route is infrequent compared to ascending infections or direct introduction.
Specific Circumstances Increasing Infection Risk
Several circumstances increase the risk of womb infection.
Childbirth and Postpartum
Childbirth and the postpartum period are particularly susceptible times. Factors like prolonged labor, premature rupture of membranes, and multiple vaginal examinations during delivery can allow bacteria to ascend. Cesarean sections carry a higher risk of postpartum womb infection compared to vaginal deliveries. Retained placental tissue or manual removal of the placenta can also create an environment conducive to infection.
Medical Procedures
Medical procedures involving the uterus elevate infection risk. Procedures such as surgical or medical abortions, dilation and curettage (D&C), hysteroscopy, and endometrial biopsies can introduce bacteria directly. IUD insertion also presents a small increased risk, particularly in the first few weeks after placement. These procedures temporarily compromise the cervical barrier.
Sexually Transmitted Infections (STIs)
Untreated STIs are a prominent cause of womb infections. Chlamydia trachomatis and Neisseria gonorrhoeae can ascend from the cervix into the uterus, leading to endometritis and pelvic inflammatory disease (PID).
Other Factors
Other factors can raise susceptibility. A compromised immune system, such as during pregnancy, can reduce the body’s ability to fight pathogens. Douching can disrupt the natural balance of vaginal bacteria, increasing infection risk. Pre-existing vaginal infections, such as bacterial vaginosis, can also alter the microbial environment, making the uterus more vulnerable.