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Progesterone PRG

What is Progesterone?

Progesterone is a steroid hormone classified as a gestagen. It is primarily produced by the corpus luteum in the ovaries and, during pregnancy, by the placenta. This hormone plays a crucial role in regulating the menstrual cycle and maintaining early pregnancy.

Progesterone Levels and the Menstrual Cycle

Progesterone levels vary throughout the female cycle. In the follicular phase, progesterone is nearly undetectable. However, levels begin to rise approximately one day before ovulation and reach their peak during the luteal phase. The hormone’s concentration reflects the development and regression of the corpus luteum.

During the second half of the cycle, progesterone is broken down into pregnanediol, which is excreted in the urine. Measuring this can provide additional information about hormonal activity.

Progesterone’s Role in Reproductive Health

Progesterone is responsible for transforming the uterine lining into a gland-rich, nutrient-dense tissue during the secretory phase, which prepares the uterus for possible implantation of a fertilised egg.

In pregnancy, progesterone helps prevent uterine contractions by relaxing the myometrium, thereby supporting foetal development. It also works alongside oestrogens in the mammary glands to stimulate the growth and differentiation of milk-producing alveoli.

Clinical Importance of Progesterone Testing

Progesterone testing is widely used in fertility assessments to:

Detect ovulation

Evaluate the luteal phase

Support diagnosis in cases of irregular menstrual cycles or infertility

Monitoring progesterone levels can help determine whether ovulation is occurring normally and if the uterine environment is prepared for implantation.

Progesterone Testing in Slough

If you're based in Slough or surrounding Berkshire areas and are undergoing fertility evaluation or experiencing hormone-related symptoms, progesterone testing can provide essential insight into reproductive health. Local clinics in Slough offer reliable hormone testing services to support personalised fertility and women’s health care plans.