What is anovulation?
Dec 31, 2021
Source: Cainiu Health
Dr. Yu Wenjing
Introduction
1. Central endocrine disorders that impair the biochemical and histological changes required for follicular wall digestion and rupture, thereby affecting follicular growth, development, and ovulation;
2. Gynecological diseases causing adhesions between the ovaries, uterus, and surrounding organs/tissues, resulting in hard, fixed masses that—when severe—may obstruct ovarian ovulation;
3. Enzyme deficiencies or insufficient prostaglandin levels.
Women of normal reproductive age ovulate once per month, typically about two weeks before the onset of their next menstrual period. The primary regulatory system governing ovulation is the hypothalamic–pituitary–ovarian (HPO) axis. Causes of anovulation include pituitary dysfunction, hypothalamic dysfunction, central nervous system disorders, intracranial lesions, immune-mediated factors, and psychological stressors. With appropriate treatment, women experiencing anovulation have a high likelihood of restoring normal ovulation and achieving pregnancy. Below, we address the question: “What causes anovulation?”
What Causes Anovulation?
1. Central Endocrine Dysregulation
When central endocrine regulation is disrupted, luteinizing hormone (LH) fails to surge adequately. This insufficient LH peak prevents the biochemical and histological changes required for follicular wall digestion and rupture—processes essential for follicular development and subsequent ovulation.
2. Gynecological Disorders
For example, in pelvic inflammatory disease (PID), tubal inflammation leads to tubal thickening, fibrosis, and cord-like appearance. Severe cases may involve adhesions between the fallopian tubes, ovaries, uterus, and adjacent structures, forming hard, fixed masses that can physically impede ovarian ovulation.
3. Enzyme Deficiency or Prostaglandin Insufficiency
Fibrinolysin, activated collagenase, and prostaglandins act on the basal membrane of the follicular wall to digest it, thereby facilitating formation of the ovarian ovulatory pore. Deficiency of these enzymes or of prostaglandins significantly compromises oocyte release.
4. Hyperprolactinemia
Elevated prolactin levels interfere with normal gonadotropin secretion from the pituitary gland, resulting in ovarian dysfunction—including impaired follicular development and disrupted ovulatory function.
5. Psychological and Emotional Factors
Chronic stress, anxiety, or fear can trigger recurrent small peaks in serum prolactin levels, thereby disrupting ovulation. This condition is often accompanied by menstrual irregularities, dysmenorrhea, and mastalgia.
The above outlines the primary causes of anovulation. We hope this information is helpful to you.
