How infections can interfere with fertility Fertility depends on a coordinated sequence of events: ovulation, sperm production and transport, fertilization, and implantation in a healthy uterine environment. Infection can disturb any step in that chain. In women, the most important…

What cervical factors in infertility mean The cervix is the lower portion of the uterus and serves as the gateway between the vagina and the uterine cavity. In natural conception, sperm must pass through the cervix before reaching the upper…

What uterine shape abnormalities are Uterine shape abnormalities are structural differences in the uterus that arise during embryologic development, usually from incomplete fusion, incomplete resorption, or atypical formation of the Mullerian ducts. Because these changes happen before birth, they are…

What endometrial polyps are Endometrial polyps are focal overgrowths of the uterine lining. They are often discovered incidentally during an infertility workup or when a person is being evaluated for abnormal uterine bleeding. Many are small and asymptomatic, and many…

Age and ovarian biology Chronological age is the most established factor affecting oocyte quality. As ovarian aging progresses, the chance of meiotic errors rises, which means the egg is more likely to carry an abnormal number of chromosomes. That matters…

Why the signs are easy to miss Most people with diminished ovarian reserve have no day-to-day symptoms. The ovaries can have fewer remaining eggs than expected without causing pain, obvious hormone symptoms, or a dramatic change in how someone feels.…

The biology of ovarian reserve The ovary contains a fixed pool of non-growing follicles that is established before birth. From that point forward, follicles are lost through normal biologic processes, including atresia, so the number of available follicles steadily falls…

How hormones coordinate fertility Reproductive function is controlled by a feedback network called the hypothalamic-pituitary-gonadal axis. The hypothalamus releases gonadotropin-releasing hormone, the pituitary responds with luteinizing hormone and follicle-stimulating hormone, and the ovaries or testes then produce sex steroids and…

Why normal cycles are reassuring, but not definitive A regular cycle often means the ovaries are likely releasing an egg in a predictable pattern, which is why clinicians pay attention to menstrual history early in the evaluation. But ovulation is…

Step 1: The brain starts the menstrual cycle Female fertility begins with the hypothalamic-pituitary-ovarian axis, a hormonal communication loop between the brain and ovaries. At the start of a menstrual cycle, the hypothalamus releases gonadotropin-releasing hormone in pulses. This stimulates…