What is the menstrual cycle?

From the Guidelines

The menstrual cycle can be managed and regulated with the use of combined hormonal contraceptives, which can be started immediately if it is reasonably certain that the woman is not pregnant. The menstrual cycle is a monthly series of hormonal changes in women of reproductive age, typically lasting 28 days but can range from 21-35 days 1. It begins with menstruation (bleeding), followed by the follicular phase when estrogen rises and an egg matures. Ovulation occurs mid-cycle when the egg is released. The luteal phase follows, with progesterone production preparing the uterus for possible pregnancy. If pregnancy doesn't occur, hormone levels drop, triggering menstruation and starting the cycle again. Some key points to consider when managing the menstrual cycle include:

• Waiting for the next menstrual period is unnecessary when starting combined hormonal contraceptives 1
• If it has been >5 days since menstrual bleeding started, additional contraceptive protection is needed for the next 7 days 1
• When switching from an IUD, a healthcare provider may consider advising the woman to retain the IUD for at least 7 days after combined hormonal contraceptives are initiated, or to abstain from sexual intercourse or use barrier contraception for 7 days before removing the IUD and switching to the new method 1 Common symptoms of the menstrual cycle include cramping, bloating, mood changes, and breast tenderness, which occur due to hormonal fluctuations, particularly changes in estrogen and progesterone. Regular cycles indicate normal reproductive health, though variations can occur due to stress, weight changes, or medical conditions. Tracking your cycle can help predict periods and identify irregularities that might require medical attention. Menstrual products include tampons, pads, menstrual cups, and period underwear, which should be changed regularly to prevent infection.

From the Research

Definition and Prevalence of Menstrual Cycle

• Menstrual cycle is a natural process in women of reproductive age, but heavy menstrual bleeding (HMB) can be a common complaint, affecting their health and quality of life 2.
• HMB is defined as excessive blood loss during menstruation, which can be measured objectively or subjectively 3, 4.

Medical Management of Heavy Menstrual Bleeding

• Medical management of HMB usually provides effective control, regardless of the underlying cause 2.
• Available medical treatments include the levonorgestrel-releasing intrauterine system (LNG-IUS), combined hormonal contraceptives, tranexamic acid, and non-steroidal anti-inflammatory drugs (NSAIDs) 2, 3, 5, 6.
• The LNG-IUS is considered a first-line medical therapy for HMB, with combined hormonal contraceptives as a second choice 2, 6.

Efficacy of Different Treatments

• The LNG-IUS has been shown to reduce menstrual blood loss to a greater extent than other medical therapies, including combined oral contraceptives and NSAIDs 2, 5.
• Combined hormonal contraceptives, such as the combined oral contraceptive pill (COCP), have been found to improve response to treatment and lower menstrual blood loss compared to placebo 6.
• NSAIDs have been shown to reduce HMB, but are less effective than tranexamic acid, danazol, or the LNG-IUS 3, 4.

Comparison of Treatments

• The LNG-IUS has been found to be more effective than COCP in reducing menstrual blood loss 6.
• There is limited evidence to compare the efficacy of combined hormonal contraceptives with NSAIDs or long-course progestogens 6.
• The contraceptive vaginal ring (CVR) has been found to have similar effects to COCP in reducing menstrual blood loss 6.