Hormone replacement, Women's Health | May 31, 2016 | Author: The Super Pharmacist
How common is abnormal uterine bleeding in women who take hormonal contraception?. There are millions of women around the world who use some form of hormonal contraception: combination oral contraceptive pills (OCPs), progestin-only pills, medroxyprogesterone acetate injections, or subdermal levonorgestrel implants being the most commonly used.
Abnormal uterine bleeding is a very common but rarely dangerous side effect of hormonal contraception, although it can still cause distress and discomfort to individuals affected by it. Because of this, it often results in the discontinuation of hormonal contraception: a study from the US, published in the American Journal of Gynaecology, found that 32% of 1,657 women who started taking oral contraceptive pills discontinued them within six months, and 46% of the discontinuations were due to unwanted side effects (1). In turn, this has been evidenced to lead to a higher prevalence of unplanned pregnancy once contraceptive methods are no longer being used (2).
A clinical examination of abnormal uterine bleeding in women who are using hormonal contraception will usually begin with a formal assessment of compliance, a thorough review of the patient’s medical history and a complete physical examination to exclude organic causes of bleeding. There will also often be a targeted laboratory evaluation of a blood sample.
The most frequent causes of abnormal uterine bleeding are pregnancy and the misuse of OCPs.
Bleeding is a very common side effects of most hormonal contraceptives during the first three months of use, with counselling (to improve compliance) and reassurance often considered to be the best and most appropriate intervention within this timeframe.
Doctors may also advise patients to stop smoking, as there are a number of studies that show cigarette smoking to be associated with increased abnormal uterine bleeding in women who are taking combined OCPs (3,4.5).
If bleeding continues more than three months treatment with supplemental oestrogen and/or a nonsteroidal anti-inflammatory drug (NSAID) may be suggested. Other treatment options are to change to an OCP with a higher oestrogen content or to a different formulation, such as a low-dose OCP containing a different progestin (6).
Additional management strategies for women with abnormal uterine bleeding who are using progestin-only contraceptive methods include further counselling and reassurance, as well as the administration of supplemental oestrogen and/or an NSAID during bleeding episodes (7).
Adding extra oestrogen while maintaining the same dose of progestin increases endometrial thickness which has the benefit of stabilising the endometrium and blood vessels, thus reducing bleeding. If bleeding still persists, some physicians may suggest switching to another low-dose OCP containing a different progestin - however, there is no evidence to suggest that switching OCPs further reduces bleeding, with a number of clinical studies finding no additional benefit to patients (8,9).
Different OCPs can also not be taken concurrently as the increased dosage of oestrogen and progestin also increases the number of negative side effects and irregular bleeding.
There is some evidence to suggest that abnormal bleeding has a greater prevalence rate in women who take progestin-only pills compared to all other OCPs or combination OCPs (10).
Progestin, a synthetic version of progesterone, is a steroid hormone that stimulates the uterus in order to prepare it for pregnancy, and abnormal bleeding is common in women using long-acting progestin-only contraceptive methods.
The dose of progestin is higher in a medroxyprogesterone injection than in levonorgestrel implants, and episodes of unpredictable bleeding occur during the first year in 70% of women who use contraceptive injections and in up to 80% of women who use contraceptive implants (11).
The most effective intervention often takes place prior to any form of hormonal contraception being taken and involves a discussion around compliance and making sure that OCPs continue to be taken despite the discomfort of their associated side effects.
A large study carried out in 1998, with over 5000 female study participants, concluded that the subjective experience of women who had abnormal uterine bleeding was a much more powerful factor in determining whether or not to continue taking medication than the actual bleeding pattern itself (12).
This suggests that counselling can prepare women to tolerate profound changes in bleeding pattern as long as they are well informed and have had an opportunity to discuss it with a physician beforehand.
The use of hormonal contraceptives is prevalent in the treatment of other conditions and has been used in an off-label treatment capacity for approximately 30 years by physicians.
The first line treatment for ovulatory dysfunction is progestin therapy, with contraceptives containing a combination of oestrogen and progesterone also evidenced to be an effective treatment. They have also been very effective in treating menstruation-related disorders such as dysmenorrhea (severe menstrual pain). Other potential benefits of hormonal contraceptives include prevention of menstrual migraines, treatment of pelvic pain due to endometriosis, treatment of bleeding due to uterine fibroids, and the reduction of serious acne (13).
1 Rosenberg MJ, Waugh MS (1998) Oral contraceptive discontinuation: a prospective evaluation of frequency and reasons Am J Obstet Gynae 179(3):577-82
2 Schrager S (2002) Abnormal uterine bleeding associated with hormonal contraception Am Fam Physician 65(10):2073-80
3 Thorneycroft IH (1999) Cycle control with oral contraceptives: a review of the literature Am J Obstet Gynecol 180(2):280–7
4 Rosenberg MJ, Waugh MS, Stevens CM (1996) Smoking and cycle control among oral contraceptive users Am J Obstet Gynecol 174:628–32
5 Krettek JE, Arkin SI, Chaisilwattana P, Monif GR (1993) Chlamydia trachomatis in patients who used oral contraceptives and had intermenstrual spotting J Obstet Gynecol 81(5):728–31
6 Bitzer J, Heikinheimo O, Nelson AL, Calaf-Asina J, Fraser IS (2015) Medical management of heavy menstrual bleeding: a comprehensive review of the literature Obstet Gynae Surv 70(2):115-30
7 Van Vliet HA, Grimes DA, Helmerhorst FM, Schulz KF (2006) Biphasic versus monophasic oral contraceptives for contraception Coch Data Syst Rev 19;(3):CD002032
8 Cerel-Suhl SL, Yeager BF (1999) Update on oral contraceptive pills Am Fam Physician 60:2073–84
9 Belsey EM (1988) The association between vaginal bleeding patterns and reasons for discontinuation of contraceptive use Contraception 38:207–25
10 Progestin-only oral contraceptives. In: Wallach M, Grimes DA, Chaney EJ, et al. (2000) eds. Modern oral contraception: updates from The Contraception Report 242–50
11 Schrager S (2002) Abnormal uterine bleeding associated with hormonal contraception Am Fam Physician 65(10):2073-80
12 Belsey EM (1998) The association between vaginal bleeding patterns and reasons for discontinuation of contraceptive use Contraception 38:207–25
13 Leung VWY, Levine M, Soon JA (2010) Mechanisms of action of hormonal emergency contraceptives Pharmacotherapy 30(2):158–168