Extended regimen combined oral contraception: A review of evolving concepts and acceptance by women and clinicians.

Focusing on women’s and clinicians’ attitudes and usage patterns related to extended or flexible regimen COCs, we collected relevant information for our review by performing a MEDLINE search of articles published in English between 1970 and 2014. We used the following search strategy: oral AND (contraception OR contraceptives) AND (extended regimens OR flexible regimens) AND (attitudes OR satisfaction OR adherence OR efficacy OR compliance OR counselling OR education). Of the 160 articles screened, 96 were included in the analysis ( Figure 1 ). Reference lists of the retrieved articles were also reviewed to identify references not found using electronic search methods. Figure 1. Flow diagram of research results. Flow diagram of research results. Although there is no universally accepted definition of what constitutes an extended COC regimen, we defined such regimens for the purpose of this review as those that include more than 28 days’ COC pills followed by 7 or fewer days of no pills, placebo or low-dose ethinylestradiol (EE). We also included flexible-extended regimens, whereby users take COCs continuously until they experience persistent unscheduled bleeding, and then begin an HFI of 7 or fewer days 27 . These extended and flexible-extended regimens differ from continuous regimens, which provide uninterrupted COCs for 1 year or more without an HFI 2 , 27 and are not the focus of this article. Furthermore, we evaluated review articles on these topics and their reference lists to identify additional relevant manuscripts.

One of the most important and recognisable trends in the evolution of COCs has been the reduction in hormone dosages to lower the risk of thrombotic events 2 . However, while the lower hormone dosages in today’s COCs are associated with a lower risk of thrombotic events, they also have the potential to increase the risk of follicular activity and escape ovulation, particularly during the traditional 7-day HFI 9 , 28 . In fact, follicular growth taking place during the 7-day HFI resembles that seen during the early follicular phase of a spontaneous menstrual cycle 29 , 30 . The limitations of the 7-day HFI prompted development of various regimens, including those with a shortened HFI (i.e., 24/4 and 26/2 regimens), regimens that substitute low-dose EE for the HFI and extended regimen COCs, which are the focus of this review. Each of these strategies has been shown to provide greater pituitary–ovarian suppression, reduce follicular development and the risk of contraceptive failure and decrease the incidence of symptoms related to hormone withdrawal 9 , 19 , 31–33 . Extended regimen COCs have been evolving, influenced by many factors, including contraceptive efficacy, safety and bleeding patterns. The first approval in the USA of an extended regimen COC was based on a large randomised controlled trial that demonstrated the efficacy of 84 days’ levonorgestrel (LNG) 150 μg/EE 30 μg followed by seven placebo days 34 . Pearl Indices, based on method failure rates, were 0.60 and 1.78 for the 84/7 and the 21/7 regimen, respectively 34 . Compared with the 21/7 regimen, the 84/7 regimen was associated with significantly fewer total days of scheduled bleeding/spotting; however, an increased incidence of unscheduled breakthrough bleeding/spotting was reported 34 , thus revealing an important limitation of extended regimen COCs compared with traditional 21/7 regimens 34 . Since unscheduled breakthrough bleeding may lead to poor adherence that can ultimately affect contraceptive efficacy 13 , modifications to the original 84/7 regimen were introduced. One such modification was to substitute low-dose EE (10 μg/day) for placebo or no treatment during the traditional HFI 35 , 36 . This strategy has been associated with increased ovarian suppression, including a potentially reduced risk of escape ovulation and unscheduled breakthrough bleeding 9 , 13 . With regard to bleeding patterns, a cross-study comparison of 84/7 regimens reported less scheduled bleeding and quicker reduction in the incidence of unscheduled bleeding when low-dose EE was substituted for the traditional 7-day HFI 13 . Since then, an even lower continuous EE dose 84/7 regimen (84 days’ LNG 100 μg/EE 20 μg plus 7 days’ EE 10 μg) has been introduced 37 , 38 . Higher EE dosages in COC regimens appear to provide greater endometrial stabilisation and less breakthrough bleeding 39 , 40 . A third type of 84/7 regimen was developed that incorporates ascending EE dosages during the first 84 days with constant LNG dosages, followed by 7 days’ low-dose EE. The timing of increased EE dosages in the pill pack is intended to coincide with the time that unscheduled bleeding with extended regimen COCs typically occurs (both in clinical practice and clinical trials) 36 , 40 . This ascending dose, extended regimen of 42 days’ LNG 150 μg/EE 20 μg, 21 days’ LNG 150 μg/EE 25 μg and 21 days’ LNG 150 μg/EE 30 μg, followed by seven days’ EE 10 μg, was demonstrated to be effective in preventing pregnancy 36 and may be associated with less unscheduled bleeding compared with other LNG/EE extended regimens 36 , 41 . This new ascending dose, extended regimen was recently approved in the USA. A final strategy to reduce unscheduled bleeding is to initiate a short HFI when persistent unscheduled bleeding occurs, a tactic known as a flexible-extended regimen. One randomised active-controlled study comparing a 24/4 regimen with two flexible-extended regimens found this to be an effective approach 27 . Two recent extensive systematic reviews of extended and continuous regimen COCs concluded that the risk of pregnancy did not differ between cyclical and extended regimens 16 , 42 . Observational data, however, suggest that regimens with shorter or fewer HFIs may be associated with reduced pregnancy rates 43 , 44 . One analysis of a retrospective claims database revealed lower contraceptive failure rates with 84/7 regimens compared with 21/7 and 24/4 regimens. At 1 year, rates of pregnancy were significantly lower with 84/7 regimens vs. 21/7 regimens (4.4% vs. 7.3%; p  < 0.0001) and with 84/7 regimens vs. 24/4 regimens (4.4% vs. 6.9%; p  < 0.0001) 44 . Since a major goal of extended regimen COCs is to reduce the incidence of scheduled withdrawal bleeds as well as overall bleeding, most studies evaluating the effectiveness of extended regimens have also included bleeding patterns as an outcome 15 , 27 , 34–37 , 45 . Moreover, since ‘escape’ follicular development and bleeding patterns are often linked, the two systematic reviews mentioned previously also address bleeding outcomes 16 , 42 . A recent Cochrane review by Edelman and colleagues 16 concluded that most trials found either no difference or less bleeding and/or spotting with extended/continuous vs. cyclical regimens, although most users of extended regimen COCs will experience occasional unscheduled (breakthrough) bleeding or spotting. Although most studies report an increased incidence of unscheduled bleeding with extended regimens during early cycles 16 , 42 , it has also been consistently documented that the frequency and intensity of such bleeding decreases over time 42 . By the fourth extended cycle, the incidence of unscheduled bleeding is generally comparable to that seen among users of conventional cyclical regimens 34 , 46 . Considering that some extended regimen COCs may provide a greater cumulative oestrogen dose compared with similarly dosed cyclical regimens, women and clinicians may be concerned that extended regimens may increase certain safety risks. Accumulating data, however, provide reassurance regarding the safety of long-term use of extended regimen COCs 16 , 47–49 . Current evidence suggests that adverse events associated with extended regimens are similar to those seen with 28-day cyclical regimens. There is also no evidence that the risk of stroke, myocardial infarction or thrombosis is increased with extended regimens compared with 28-day regimens 42 . Since the incidence of symptoms associated with hormone withdrawal and menstruation is related to the number of hormone withdrawal episodes, as the number of such episodes decreases so should their associated symptoms 16 , 42 . Extended regimens clearly improve dysmenorrhoea by decreasing the total number of withdrawal bleeds 42 . In an early study of 84 days’ EE and lynestrenol and 7 days’ placebo, 20% of participating women had fewer menstrual symptoms compared with their previous pill regimen 50 . These benefits are particularly apparent among women who experience premenstrual syndrome or symptoms associated with the HFI when using conventional regimens 42 . In a study of the use of extended regimens to delay withdrawal bleeding and reduce hormone withdrawal symptoms, 41–86% of women who chose extended regimen COCs experienced an improvement in their symptoms 51 . Among the 59% of women who chose to continue using extended regimen COCs, 94% reported improvement in their quality of life 51 . In one study of adolescents who adhered to an extended regimen, the prevalence of dysmenorrhoea decreased by 56%, spending on painkillers decreased by 75% and absenteeism from work and school decreased by 92% 52 . Many women would prefer to eliminate or reduce the frequency of scheduled bleeding if given the choice ( Table 1 ) 25 , 26 . In one of the first studies to evaluate an 84/7 COC regimen, 82% of 196 participants welcomed having fewer withdrawal bleeds; both women and clinicians appreciated this and other aspects related to taking an extended regimen COC 50 . Although the lack of scheduled bleeding was disturbing to some, many women and clinicians felt this regimen was easier to follow and was well accepted. In fact, 91% of women still using the extended regimen at the end of the study refused to revert to the standard monthly regimen 50 . Table 1. Attitudes of women towards extended regimen contraception: results of representative surveys of reproductive aged women 25 , 26 , 61 , 63 , 67 .         Desired frequency of menstruation (%) Prior use of hormonal contraceptives to delay withdrawal bleeding (%) Would consider or have an interest in using COCs to manipulate scheduled bleeding (%) Reference Region N Population Monthly Less than monthly Never     Andrist et al ., 2004 25 USA 1470 Women aged 18–40 years 41 59 33 22 60 Glasier et al ., 2003 67 China 200 Women attending family planning clinics 42 39 6 0 37 Nigeria 200   71 12 13 20 73 Scotland, UK 200   33 20 37 23 65 South Africa 68 black women   49 27 9 60 52     66 white women   30 26 29 32 64 Lakehomer et al ., 2013 26 USA 1719 Female university students aged ≥18 years 33 40 28 17% of 1374 users altered regimen by not following contraceptive instructions NR   Merki-Feld et al ., 2014 63 Switzerland 292 Women of childbearing age 37 32 30 NR 44   Wiegratz et al ., 2004 61 * Germany 310 15- to 19-year-old women 26 27 41 22 74       295 25- to 34-year-old women 35 22 37 35 50   *Percentages may not total 100% due to women who did not answer the question. NR, not reported. Attitudes of women towards extended regimen contraception: results of representative surveys of reproductive aged women 25 , 26 , 61 , 63 , 67 . *Percentages may not total 100% due to women who did not answer the question. NR, not reported. According to a 2007 Canadian consensus statement, extended regimens are also associated with a greater reduction in the use of hygiene products compared with conventional cycles 42 , 53 . The lower use of these products and lower associated out-of-pocket expenses constitute yet another reason for women to prefer extended regimen COCs. Moreover, the increased number of tablets consumed does not appear to increase the overall costs of these regimens 42 . Reduced withdrawal bleeding may also reduce the risk of anaemia in women using extended COC regimens. A recent study indicated, however, that relatively few women are aware of this potential benefit 54 . Missed pills, in the real world, particularly those missed during the first week of COC use, may increase the risk of follicular development and cause contraceptive failure 9 , 10 . It has been hypothesised that when extended regimen COCs are used to avoid menstruation for convenience or personal preference, they may lead to improved adherence and greater user satisfaction due to a reduction in the number of hormone withdrawal episodes and greater number of active pills available 42 , 46 . In one survey of 617 gynaecologists following 3316 women throughout France, 23% of women using conventional COCs reported missing a pill at least once during a 28-day cycle, and 42% of women who missed a pill did so during the first week following the HFI 55 . This led the authors to conclude that, by reducing the opportunity to miss pills during the first week of the cycle, using continuous regimens might improve compliance. Despite this, a recent Cochrane analysis found no difference in compliance or adherence between users of extended or continuous regimen COCs when patient compliance was reported 16 . User satisfaction could possibly be considered a proxy for user adherence. Indeed, high user satisfaction has been consistently reported with extended regimen COCs 16 , 27 , 34 , 42 , 56 , 57 , and this satisfaction typically increases as the number of bleeding episodes decreases 58 . By contrast, another study with a flexible-extended regimen COC reported lower satisfaction with continuous than with cyclical COCs, both with regard to satisfaction with bleeding outcomes and overall satisfaction 57 . It is noteworthy, however, that survey data indicate that the majority of women using hormonal contraceptives would accept unpredictable bleeding initially if they had fewer withdrawal bleeds over time 59 . In an early study of Dutch women’s preferences, 81% of those surveyed would prefer to modify their menstrual cycle (less painful, shorter or lighter periods). Most of these women preferred to have a bleeding frequency of less than once a month or never 60 . Approximately two-thirds of reproductive aged women surveyed in Germany indicated they would prefer to bleed less frequently than monthly, and 37–46% would prefer never to bleed 61 . Among 350 Italian women of reproductive age, only 32% indicated a preference to bleed monthly, whereas 68% preferred to bleed less than once a month 62 . Among COC users, approximately 57% preferred to bleed less than once a month and 26% preferred to bleed every 3 months 62 . Contemporary Swiss women have similar attitudes towards menstrual bleeding. A recent study reported that 32% preferred to bleed every 2–6 months and 29% preferred not to bleed at all 63 . Interestingly, preferences for bleeding frequency in this study did not appear to differ between women who experienced menstrual symptoms and those who did not. The findings of this survey suggested that predictability of bleeding may be more important for some women than the ability to postpone it. Indeed, more than 80% of women felt that the predictability of bleeding and avoidance of unscheduled bleeding were very important 63 . A desire for less frequent bleeding is not limited to women who experience symptoms related to menstruation or withdrawal bleeding. In one study of 270 women without menstrual symptoms, 76% reported that menstrual periods interfered with their sexual life, 29% preferred not having their period at work and 48% felt that menstruation interfered with their sporting activities 18 . If given the choice, more than half of the participants indicated that they would prefer less frequent periods 18 . Of these women who would prefer less frequent periods, half would prefer amenorrhoea. Importantly, 73% of the women who preferred a reduction in menstrual frequency said they would use a drug to accomplish this 18 . Data indicate that many women have already used COCs to delay bleeding, suggesting that many would welcome a COC option that modified the frequency of their scheduled bleeding episodes. A 2008 survey reported that approximately one-third of Italian COC users had modified their COC regimen to delay the occurrence of withdrawal bleeding 62 . A more recent survey of US university students found that 17% of respondents had altered their scheduled bleeding pattern by deviating from the instructions in the package insert 26 . While women who preferred a structured schedule and consistent monthly cycles were less likely to manipulate the timing of their scheduled bleeding, women who were older, those who used oral (but not transdermal or vaginal) contraceptives and those who preferred to bleed less frequently were more likely to report manipulating their COC schedule 26 . Clinicians providing guidance regarding the off-label manipulation of 28-day COC formulations to approximate extended regimens should consider the possibility that this practice may result in misuse, potentially increasing the risk of contraceptive failure. Despite the consistent survey data demonstrating that the majority of reproductive aged women preferred to bleed less often than monthly 25 , 26 , 56 , 64 , a US-based study found that 73% of women had never even heard of using COCs to manipulate their monthly bleeding episodes 25 . Of concern, only half of the university students surveyed by Lakehomer et al . 26 in a US study reported learning about cycle manipulation from health care providers (HCPs). Another study of family planning clinics in London revealed that extended regimen COCs were discussed with as few as 6% of women attending centres that provided specialist contraceptive services 65 . This finding is corroborated by previous research from Spain that demonstrated that 90% of women had never been offered the option to suppress monthly bleeding by their gynaecologist 66 . A lack of discussion or recommendation for extended regimens by HCPs, particularly in certain European countries, may be explained, at least in part, by the lack of availability of approved extended regimen COCs. In the US, where several extended regimen COCs are approved for use, it appears that only 2.5% of women prescribed COCs are prescribed an extended regimen COC 24 . Although this figure may not represent their actual use, it is evident that many women interested in menstrual suppression are not offered extended regimen COCs by their HCPs. Attitudes and beliefs about menstruation among women around the world have been evolving. Although many women still believe that monthly bleeding is necessary, others would prefer to bleed less frequently or not at all ( Table 1 ) 26 , 67 . These changing preferences have been observed in women from both developed and developing countries, and, as reviewed below, have been particularly well documented in studies of Western European women 16 , 25 , 56 , 67 , 68 . Because preferences regarding menstruation are related to cultural beliefs, they may vary from region to region 69 . Even when women learn about how using extended regimens can reduce the frequency of bleeding, some may be concerned about this approach ( Table 1 ) 50 . For example, some may worry about the risk of ‘menstrual build-up,’ fear that skipping monthly bleeding may lead to an ‘unnatural state,’ or worry that each missed period represents a possible pregnancy 16 . However, with reassurance regarding the safety of this approach, most women would prefer to delay or never have a period 16 , 60 , 67 , 68 . Among gynaecologists practising in Brazil, 93% of those surveyed indicated that medically-induced amenorrhoea represents no risk to women’s health and 83% said they prescribed contraceptives to control menstruation or induce amenorrhoea 70 . Still, not all HCPs are convinced of the clinical utility of extended regimen COCs. In the study of family planning clinics in London 65 , both HCPs and women expressed concerns about the risks of avoiding monthly bleeding, the impact of extended regimen COCs on future fertility and the clinical impact of breakthrough bleeding. Return to fertility. Some women and clinicians have expressed concerns about resumption of cycles and fertility following the use of hormonal contraceptives that suppress menstruation 50 , 54 , 65 . Although studies evaluating return to fertility following the discontinuation of extended regimen COCs are relatively uncommon, those that have assessed this outcome have reported that fertility returns promptly after their discontinuation 42 , 71 , 72 . Among women discontinuing extended regimen COCs without starting other hormonal contraceptives, the median time to withdrawal bleeding was 32 days, with 77% of women returning to ovulatory capacity (defined as serum progesterone ≥15.9 nmol/L) within 32 days and 99% of women having spontaneous menstruation or pregnancy within 3 months of discontinuation 73 . Effects on the endometrium. Theoretical concerns about the potential effects on the endometrium of extended regimen COCs that contain more days of oestrogen-containing pills are common among clinicians but also among some women considering an extended regimen. Histological examinations of the endometrial lining have, however, confirmed an inactive endometrium, likely induced from adequate progestin exposure, in women using either cyclical or extended regimens 16 , 74 . These findings have been confirmed by multiple large trials of extended regimen COCs, demonstrating that long-term use of these regimens does not cause endometrial pathology but largely produces an atrophic endometrium 42 , 46 , 74 . Similarly, an analysis of the endometrial effects of an extended LNG 150 μg/EE 30 μg + EE 10 μg COC found no evidence of endometrial hyperplasia and confirmed the endometrial safety of this regimen 75 . Studies have also demonstrated a rapid return to a normal cycling endometrium histology after the discontinuation of extended regimen LNG/EE COCs. 74 , 75 Recent evidence suggests that HCPs whose focus is women’s health are comfortable with prescribing extended regimen COCs; 70–92% of US clinicians have recommended them in their practices 70 , 76–79 . Not surprisingly, gynaecologists are more likely to prescribe extended regimens compared with primary care physicians 77 . The most commonly prescribed extended regimen COC in the USA is an 84/7 formulation that incorporates a 7-day HFI 76 . The majority of general HCPs (>73%) continue to prescribe 28-day COCs as the most common regimen 76 . In the UK, family planning specialists appear to have been slower to adopt extended regimen COCs than those in other countries. A survey of clinicians at three family planning clinics in London revealed that only one of the three clinics initiated and maintained guidelines for the use of extended regimens 65 . The frequency of counselling women about extended regimen COCs was highly variable 65 . In the clinic that maintained guidelines, 60% of staff provided counselling on extended regimen COCs to more than 50% of women 65 . In the other two clinics, extended regimen COCs were discussed with only 6–20% of women. Approximately one-third of respondents felt more comfortable prescribing 21/7 regimens, due, in large part, to a lack of familiarity with other regimens 65 . Respondents also expressed an interest in receiving more information on prescribing recommendations and on the long-term effects of extended regimen COC use. The results of this survey provide evidence that more training on the use of extended regimen COCs may be needed, even among family planning specialists 65 . Extended regimen COCs seem to be more frequently prescribed in other areas of Europe and in South America. Among female gynaecologists practising in Germany and Austria, 97% had prescribed extended regimen COCs at least once 80 . One Brazilian survey of 1097 gynaecologists found that 93% of women seen in their practices had requested extended or continuous regimen COCs; 94% of those surveyed had already prescribed them at least once 81 . Interestingly, the female gynaecologists surveyed were more likely to prescribe extended regimen COCs, while the male gynaecologists preferred prescribing continuous regimens 81 . A second study confirmed that Brazilian gynaecologists were favourably inclined towards prescribing these regimens for control of menstrual bleeding or to induce amenorrhoea 70 . Users of extended regimen COCs do not appear to have an increased risk of breast cancer, infertility or thrombosis beyond that of conventional 28-day regimens 76 . Attitudes and perceptions of surveyed HCPs regarding the use of extended regimen COCs revealed that 82% of the participants did not believe that they increased health risks. Much smaller percentages believed they increased the risk of breast cancer (8%), infertility (4%) or thrombosis (14%) compared with 28-day regimens 76 . Among German and Austrian gynaecologists, only 3% expressed concerns related to these agents’ effects on the breast or fertility, or other adverse events 80 . Perhaps the greatest endorsement of the safety and utility of extended regimen COCs comes from female gynaecologists’ widespread personal contraceptive choices 82 . Almost all physicians interviewed for one survey reported using hormonal contraceptives to control their own bleeding or that of their partner 70 . Such data are particularly important considering that personal contraceptive use may affect HCPs’ own prescribing and counselling practice 83 . Concerns regarding the use of extended regimen COCs can likely be addressed through effective counselling. Research has shown that clinicians who use a structured, patient-centred approach to contraceptive counselling that includes shared decision-making may influence contraceptive use, and it is an approach preferred by women 84–87 . Shared decision-making represents an approach that considers patient preferences and respects patient autonomy, using a structure that enables clinicians to emphasise highly effective contraceptives while considering the woman’s preferences 84 . Preliminary data suggest that approaches involving the tenets of shared decision-making may increase the use of effective contraception 85 , but data on their impact on extended regimen COC use is lacking. Studies of interventions designed to improve the delivery of information about contraception have been limited and mostly unsuccessful 84 , 88 , but several best practices have been proposed for general contraceptive counselling. Women should, first and foremost, understand that the use of an extended regimen COC to delay or eliminate scheduled bleeding episodes is not harmful to their health 42 , 46–49 , 89–91 ( Table 2 92–95 ). Clinicians should also ensure that they provide information about the side effects of the contraceptives considered and communicate about these side effects in a way that is meaningful to women 84 . Issues to discuss include the long-term safety of extended regimens 47–49 , the likelihood of unscheduled bleeding in early cycles 16 , 42 , the rapid return to fertility once extended regimen COCs are discontinued 42 , 71 and other potential benefits of extended regimen COCs 16 , 42 , 72 . Given the high rate of discontinuation of COCs, proactively addressing possible logistical, financial or medical problems that may arise and providing recommendations for addressing these problems may ultimately improve the use of extended regimen COCs 84 . Table 2. Key points for counselling women considering extended regimen COCs 92–95 . Monthly withdrawal bleeding is not medically necessary when a woman uses COCs Using extended COC regimens reduces episodes of withdrawal bleeding: experiencing fewer withdrawal bleeds may be more convenient and better suit the medical and lifestyle needs of some women; having to fill prescriptions only four times a year is another benefit Menstrual blood and/or the lining of the uterus do not ‘build up’ with extended use of COCs; the lining of the uterus is thin with all COC regimens Irregular, unpredictable bleeding or spotting may occur in the initial cycles of therapy and may be more frequent with extended regimens than with traditional cyclical regimens; while this can be bothersome, it is usually not medically worrisome Irregular bleeding and spotting almost always gets better after the first few months of COC use Evidence suggests that the safety profiles of extended regimens and traditional cyclical regimens are similar As with all COCs, fertility will return when extended regimen COCs are discontinued Key points for counselling women considering extended regimen COCs 92–95 . Monthly withdrawal bleeding is not medically necessary when a woman uses COCs Using extended COC regimens reduces episodes of withdrawal bleeding: experiencing fewer withdrawal bleeds may be more convenient and better suit the medical and lifestyle needs of some women; having to fill prescriptions only four times a year is another benefit Menstrual blood and/or the lining of the uterus do not ‘build up’ with extended use of COCs; the lining of the uterus is thin with all COC regimens Irregular, unpredictable bleeding or spotting may occur in the initial cycles of therapy and may be more frequent with extended regimens than with traditional cyclical regimens; while this can be bothersome, it is usually not medically worrisome Irregular bleeding and spotting almost always gets better after the first few months of COC use Evidence suggests that the safety profiles of extended regimens and traditional cyclical regimens are similar As with all COCs, fertility will return when extended regimen COCs are discontinued Information on various COC regimens and options should be presented to meet each woman’s individual needs. Such targeted counselling is particularly important given the evidence suggesting that the quality of physician–patient communication may help ensure patient adherence and patient satisfaction 24 , 70 , 78 , 96 . By considering women’s personal preferences regarding menstruation and scheduled bleeding, clinicians can individualise COC regimens to best meet their needs 42 . For example, it may be reassuring to women with a higher body mass index that studies of the safety and efficacy of extended regimen COCs have included such women 35 , 36 . Despite considerable evidence supporting the efficacy and safety of extended regimen COCs, some clinicians may benefit from targeted training regarding these regimens to help expand their patients’ choices and increase the acceptance of extended regimens around the world 65 .

A considerable body of evidence supports the efficacy, safety, convenience and clinical benefits of extended regimen COCs. Many women, however, lack awareness of the availability or utility of extended regimens. Other women may have misperceptions regarding the need for monthly bleeding or the safety of extended regimens. Consequently, women who wish to use COCs should be offered the opportunity to choose the frequency of their withdrawal bleeding. Increased awareness and empowerment of women through patient-centred counselling may help meet the needs of those desiring effective contraception with fewer monthly bleeds.

Combined oral contraceptives (COCs) have undergone numerous changes since they were introduced over 50 years ago. Early COCs consisted of 28-day pill packs, typically known as 21/7 COC regimens 1 . Such regimens, still in widespread use, provide 21 days of active combination hormone pills followed by a hormone-free interval (HFI) of seven placebo pills 2 , 3 . The aim of these regimens is to induce withdrawal bleeding every 28 days, which historically has served to mimic a monthly menstrual cycle and reassure the user that she is not pregnant 1–3 . Several variations of the original 21/7 regimen, which maintain a 28-day cycle but have fewer hormone-free days (i.e., 24/4 and 26/2), are now available and offer the benefits of shorter, lighter withdrawal bleeds 4–6 . It is recognised, however, that monthly withdrawal bleeds in any form are unnecessary and often inconvenient. Moreover, hormone withdrawal during the HFI may increase the risk of escape ovulation and induce a variety of symptoms, such as headaches, bloating and pelvic pain 1 , 7–11 . One strategy to minimise withdrawal bleeding and maintain ovarian suppression has been to extend the COC cycle beyond 28 days. In this increasingly popular strategy, the number of active pills administered per cycle and the amount of time between HFIs is increased 12 . By extending the time between scheduled bleeding episodes, an important objective is achieved: namely, the total number of scheduled bleeding episodes is reduced 13 . Extended regimen COCs may reduce the interference of scheduled bleeding with daily activities, such as sexual activity, exercise, sports and work (including menstruation-related absence from work) and reduce the costs and inconvenience associated with feminine hygiene products 14–18 . In addition to allow women the option to avoid menstruation, extended, flexible-extended and continuous regimens have become recognised in recent years as useful approaches to treat endometriosis, dysmenorrhoea and menstrual-related symptoms 16 , 19–23 . Given these various positive attributes, one might possibly expect the adoption of extended regimen COCs to be nearly universal; however, there is evidence to suggest that such regimens are underused 24–26 . We were interested, therefore, to understand whether attitudes or perceptions of women and clinicians constituted barriers to the use of extended regimen COCs. The objective of this review is to summarise the available information on: (1) the evolution and rationale for extended regimen COCs, considering their efficacy, safety and clinical utility; (2) women’s and clinicians’ attitudes towards extended regimen COCs; and (3) strategies for improving communication about COC options to increase awareness among clinicians and women about the potential benefits of extended regimen COCs.