The ovary (Japanese: 卵巣, ransō) is the principal female gonad, a pair located in the pelvic cavity on either side of the uterus. It produces, matures, and ovulates eggs, and as an endocrine organ it produces and secretes female hormones including estrogen (follicular hormone) and progesterone (luteal hormone).

Anatomical features

The ovary is a flattened oval organ, about 3–4 cm along its long axis in the adult woman. It is fixed by ligaments to the pelvic side wall on either side of the uterus, not directly attached to the uterus (a separate structure from the fallopian tube). Internally it divides into cortex and medulla. The cortex contains many follicles (structures of an egg and surrounding cells), and a mature follicle (Graafian follicle) ruptures to release an egg in ovulation, timed to the menstrual cycle.

At birth the ovary already holds an estimated 1–2 million primordial follicles. Most regress before puberty, and only about 400–500 are ovulated across a lifetime. Unlike the male testis, which produces sperm continuously throughout life, the female eggs complete their formation before birth.

Ovarian hormones and sexual function

The hormones the ovary produces directly govern female sexual function and characteristics. Estrogen drives breast development, endometrial proliferation, vaginal lubrication, and maturation of the external genitalia, the formation of female secondary sexual characteristics. It also affects libido and sexual response, and changes in estrogen level are associated in some research with cyclical variation in desire. Progesterone is secreted by the corpus luteum after ovulation, maintaining the endometrium for implantation and raising basal body temperature; it is deeply involved in the onset of menstruation when pregnancy does not occur. Around the ovulatory phase (mid-cycle), estrogen and luteinising hormone peak, and several studies report a tendency for desire to rise at this time. Yet human sexual behaviour does not simply follow the hormone cycle; it operates under the combined influence of social and psychological factors.

Menopause and changes in ovarian function

From the late 40s to the 50s, as the ovarian follicles are depleted, ovarian function declines and estrogen production falls sharply. This transition is menopause (around the cessation of menstruation), and the drop in estrogen can produce symptoms such as hot flashes, sweating, vaginal dryness, change in libido, and reduced bone density. As a sexual change in menopause, reduced vaginal lubrication and reduced vaginal-wall elasticity can lead to discomfort or pain during intercourse (dyspareunia). Hormone replacement therapy (HRT) and local estrogen therapy are used to improve these symptoms.

Ovarian disease and effects on sexual health

Ovarian cysts, polycystic ovary syndrome (PCOS), and ovarian endometriosis can cause menstrual irregularity, pain, and infertility, directly affecting sexual health. PCOS may involve excess androgen (male hormone) production and is associated in some cases with change in libido and hirsutism.

Related terms

• Sex hormones
• Pregnant body