Sterility

Sterility is the state of being unable to reproduce. In biology, it refers to an organism that cannot produce viable offspring. In medical and industrial contexts, sterility also denotes the absence of viable microorganisms in a substance, product, or environment. It is distinct from infertility, which is a reduced or absent ability to conceive but not always absolute.

Reproductive sterility in humans is usually described as an absolute or permanent barrier to conception. It can be congenital (such as gonadal agenesis or congenital absence of the vas deferens) or acquired through disease, injury, or treatment that damages gonads or reproductive tracts (for example, chemotherapy, radiation, infections such as mumps orchitis or pelvic inflammatory disease). Some forms are potentially reversible if treated early, while others are permanent.

Diagnosis of reproductive sterility involves semen analysis, assessment of semen volume and quality, hormonal testing, imaging (ultrasound), and evaluation of female fertility factors. Management depends on the cause and may include medical treatment, surgical repair, or assisted reproductive technologies such as in vitro fertilization (IVF) with the partner's or donor gametes. Reproduction-sparing options exist for some conditions; where sterilization is chosen, it is usually considered permanent contraception.

In microbiology and healthcare, sterility refers to the absence of any viable microorganisms in a product or surface. Achieving sterility requires validated sterilization procedures, such as moist heat in an autoclave, dry heat, chemical sterilants (ethylene oxide, hydrogen peroxide), radiation, or sterile filtration for heat-sensitive liquids. Sterility testing and process validation follow regulatory standards to ensure product safety, especially for medical devices and pharmaceuticals.