Omitting the first oral contraceptive pills of the cycle does not automatically lead to ovulation

Effects of an oral contraceptive containing estetrol and drospirenone on ovarian function

OBJECTIVE

To evaluate the effects of estetrol 15 mg/drospirenone 3 mg on ovarian function.

STUDY DESIGN

Single-center, randomized, open-label, parallel study in healthy young women with proven ovulatory cycles. Participants received either estetrol 15 mg/drospirenone 3 mg (E4/DRSP) (n = 41) or ethinylestradiol 20 µg/drospirenone 3 mg (EE/DRSP) (n = 41) in a 24/4-day regimen for 3 consecutive cycles. Follicular size and endometrial thickness were measured by transvaginal ultrasound every 3 days in cycles 1 and 3. Blood was sampled for hormone analysis. Ovarian function expressed as Hoogland score was based on follicular size, serum estradiol (E2) and progesterone (P) concentrations. Ovulation was defined as a ruptured follicle-like structure >13 mm with serum E2 concentrations >100 pmol/L and serum P concentrations >5 nmol/L. We assessed return of ovulation after treatment cessation, and safety throughout the study.

RESULTS

None of the participants ovulated with E4/DRSP use, while one participant ovulated once and one participant ovulated twice during EE/DRSP treatment. Most participants had a Hoogland score of 1 (no ovarian activity) in cycle 1 (85.0% and 82.9% of participants on E4/DRSP and EE/DRSP, respectively) and in cycle 3 (65.8% and 83.8%, respectively). E4/DRSP suppressed follicle-stimulating hormone and luteinizing hormone to a lesser extent than EE/DRSP, whereas both treatments comparably suppressed E2 and P and endometrial thickness. Return of ovulation occurred, on average, 15.5 days after E4/DRSP treatment discontinuation. E4/DRSP was safe and well-tolerated.

CONCLUSIONS

E4 15 mg/DRSP 3 mg results in adequate ovulation inhibition and ovarian function suppression, comparable to a marketed combined oral contraceptive containing EE/DRSP.

IMPLICATIONS STATEMENT

Treatment with E4 15 mg/DRSP 3 mg showed complete ovulation inhibition, despite less suppression of follicle-stimulating hormone and luteinizing hormone compared to EE/DRSP. If it becomes commercially available, E4/DRSP, containing a naturally occurring estrogen, should be as effective as EE/DRSP.

The 7-day contraceptive hormone-free interval should be consigned to history

AIM

This review summarises the available data on the disadvantages of the 7-day contraceptive-free interval (CFI) of combined oral contraceptives (COCs), in contrast to shorter CFIs or continuous use - including flexible regimens - and provides recommendations for practice.

METHODS

Relevant papers were identified by Medline and PubMed. The final reference list was generated on the basis of relevance to the review, with priority given to systematic reviews and randomised controlled trials.

RESULTS

There is considerable inter- and intra-individual variation in the absorption and metabolism of COCs. Even with perfect use, the loss of endocrine suppression during the standard 7-day CFI allows follicular development with the risk of escape ovulation in a vulnerable minority. This risk increases in typical users whenever the CFI is prolonged: late restarts are a common reason for pill omissions. Shortening or eliminating the CFI improves contraceptive efficacy using the lowest doses available, without evidence to date of compromised safety.

CONCLUSIONS

There is no scientific evidence to support a 7-day CFI and it should be replaced either by a continuous flexible regimen, or extended regimens with a shortened CFI, prescribed first-line. In women preferring a monthly 'bleed', a 4-day CFI similarly provides a greater safety margin when pills are omitted.

Effect of missed combined hormonal contraceptives on contraceptive effectiveness: a systematic review

BACKGROUND

Combined hormonal contraceptives (CHCs) are popular methods of reversible contraception in the United States, but adherence remains an issue as reflected in their lower rates of typical use effectiveness. The objective of this systematic review was to evaluate evidence on the effect of missed CHCs on pregnancy rates as well as surrogate measures of contraceptive effectiveness (e.g., ovulation, follicular development, changes in hormone levels, cervical mucus quality).

STUDY DESIGN

We searched the PubMed database for peer-reviewed articles published in any language from database inception through April 2012. We included studies that examined measures of contraceptive effectiveness during cycles with extended hormone-free intervals or nonadherence (e.g., omission of pills, delayed patch replacement) on days not adjacent to the hormone-free interval. We used standard abstract forms and grading systems to summarize and assess the quality of the evidence.

RESULTS

The search strategy identified 1387 articles, of which 26 met our study selection criteria. There is wide variability in the amount of follicular development and risk of ovulation among women who extended the pill-free interval to 8-14 days; in general, the risk of ovulation was low, and among women who did ovulate, cycles were usually abnormal (i.e., low progesterone levels, small follicles and/or poor cervical mucus) (Level I, good, indirect to Level II-3, fair, indirect). Studies of women who missed one to four consecutive pills or 1-3 consecutive days of delay before patch replacement at times other than adjacent to the hormone-free interval reported little follicular activity and low risk of ovulation (Level I, fair, indirect to Level II-3, poor, indirect). Studies comparing 30 mcg versus 20 mcg mc ethinyl estradiol pills showed more follicular activity when 20 mcg ethinyl estradiol pills were missed (Level I, good, indirect).

CONCLUSION

Most of the studies in this evidence base relied on surrogate measures of pregnancy risk and ranged in quality. For studies providing indirect evidence on the effects of missed CHCs, it is unclear how differences in surrogate measures correspond to pregnancy risk. Fewer studies examined the transdermal patch and vaginal ring than combined oral contraceptives.

Missed hormonal contraceptives: new recommendations

OBJECTIVE

To provide evidence-based guidance for women and their health care providers on the management of missed or delayed hormonal contraceptive doses in order to prevent unintended pregnancy.

EVIDENCE

Medline, PubMed, and the Cochrane Database were searched for articles published in English, from 1974 to 2007, about hormonal contraceptive methods that are available in Canada and that may be missed or delayed. Relevant publications and position papers from appropriate reproductive health and family planning organizations were also reviewed. The quality of evidence is rated using the criteria developed by the Canadian Task Force on Preventive Health Care.

BENEFITS, HARMS, AND COSTS

This committee opinion will help health care providers offer clear information to women who have not been adherent in using hormonal contraception with the purpose of preventing unintended pregnancy.

SPONSORS

The Society of Obstetricians and Gynaecologists of Canada. SUMMARY STATEMENTS: 1. Instructions for what women should do when they miss hormonal contraception have been complex and women do not understand them correctly. (I) 2. The highest risk of ovulation occurs when the hormone-free interval is prolonged for more than seven days, either by delaying the start of combined hormonal contraceptives or by missing active hormone doses during the first or third weeks of combined oral contraceptives. (II) Ovulation rarely occurs after seven consecutive days of combined oral contraceptive use. (II) RECOMMENDATIONS: 1. Health care providers should give clear, simple instructions, both written and oral, on missed hormonal contraceptive pills as part of contraceptive counselling. (III-A) 2. Health care providers should provide women with telephone/electronic resources for reference in the event of missed or delayed hormonal contraceptives. (III-A) 3. In order to avoid an increased risk of unintended pregnancy, the hormone-free interval should not exceed seven days in combined hormonal contraceptive users. (II-A) 4. Back-up contraception should be used after one missed dose in the first week of hormones until seven consecutive days of correct hormone use are established. In the case of missed combined hormonal contraceptives in the second or third week of hormones, the hormone-free interval should be eliminated for that cycle. (III-A) 5. Emergency contraception and back-up contraception may be required in some instances of missed hormonal contraceptives, in particular when the hormone-free interval has been extended for more than seven days. (III-A) 6. Back-up contraception should be used when three or more consecutive doses/days of combined hormonal contraceptives are missed in the second and third week until seven consecutive days of correct hormone use are established. For practical reasons, the scheduled hormone-free interval should be eliminated in these cases. (II-A) 7. Emergency contraception is rarely indicated for missed combined hormonal contraceptives in the second or third week of the cycle unless there are repeated omissions or failure to institute back-up contraception after the missed doses. In cases of repeated omissions of combined hormonal contraceptives, emergency contraception may be required, and back-up contraception should be used. Health care professionals should counsel women in these situations on alternative methods of contraception that do not demand such stringent compliance. (III-A).

20 microg versus >20 microg estrogen combined oral contraceptives for contraception

BACKGROUND

Concern about estrogen-related adverse effects has led to progressive reductions in the estrogen dose in combination oral contraceptives (COCs). However, reducing the amount of estrogen to improve safety could result in decreased contraceptive effectiveness and unacceptable changes in bleeding patterns.

OBJECTIVES

To test the hypothesis that COCs containing </=20 microg ethinyl estradiol (EE) perform similarly as those containing >20 microg in terms of contraceptive effectiveness, bleeding patterns, discontinuation, and side effects.

SEARCH STRATEGY

We searched computerized databases (CENTRAL, MEDLINE, EMBASE, and POPLINE) up to January 2008, and searched the references of eligible trials. We wrote to oral contraceptive manufacturers to identify eligible trials.

SELECTION CRITERIA

English-language reports of randomized controlled trials were eligible that compare a COC containing </=20 microg EE with a COC containing >20 microg EE. We excluded studies where the interventions were designed to be administered for less than three consecutive cycles or to be used primarily as treatment for non-contraceptive conditions. Trials had to report on contraceptive effectiveness, bleeding patterns, trial discontinuation due to bleeding-related reasons or other side effects, or side effects to be included in the review.

DATA COLLECTION AND ANALYSIS

The primary reviewer evaluated all titles and abstracts located in the literature searches to determine whether they met the inclusion criteria. Two reviewers independently extracted data from the studies identified for inclusion. We wrote to the authors when clarifications or additional data were needed. Data were entered and analyzed with RevMan 4.2.

MAIN RESULTS

No differences were found in contraceptive effectiveness for the 13 COC pairs for which this outcome was reported. Compared to the higher-estrogen pills, several COCs containing 20 microg EE resulted in higher rates of early trial discontinuation (overall and due to adverse events such as irregular bleeding) as well as increased risk of bleeding disturbances (both amenorrhea or infrequent bleeding and irregular, prolonged, frequent bleeding, or breakthrough bleeding or spotting).

AUTHORS' CONCLUSIONS

While COCs containing 20 microg EE may be theoretically safer, this review did not focus on the rare events required to assess this hypothesis. Data from existing randomized controlled trials are inadequate to detect possible differences in contraceptive effectiveness. Low-dose estrogen COCs resulted in higher rates of bleeding pattern disruptions. However, most trials compared COCs containing different progestin types, and changes in bleeding patterns could be related to progestin type as well as estrogen dose. Higher follow-up rates are essential for meaningful interpretation of results.

Pregnancy intentions and contraceptive behaviors among adolescent women: a coital event level analysis

PURPOSE

Measuring pregnancy intentions has been difficult. This study examines questions regarding pregnancy intentions and their association with adolescents' sexual and contraceptive behaviors longitudinally.

METHODS

Adolescent women completed an interview about pregnancy intentions followed by a 3-month daily diary period reporting coital activity and contraception use. Interviews assessed pregnancy intentions with: "Are you trying to get pregnant now?," "Are you trying to keep from getting pregnant now?," and "I'm very committed to not getting pregnant at this time in my life." The measured outcome was the occurrence of contraceptive protected versus non-protected coitus collected from diary data. Logistic regression was used to assess this relationship.

RESULTS

A total of 289 women completed 677 face-to-face interviews and subsequent 3 months of diary collection. In all, 194 reported having sex during diary collection. Women trying to keep from getting pregnant (n = 265) had 51.8% of 2533 coital events covered by contraception, whereas 13.1% of 818 coital events were protected in those women who were not trying to keep from getting pregnant (OR = 9.2, 95% CI = 6.0, 13.9). Women who agreed that they were committed to not getting pregnant were more likely to have coital events protected (50.5% of 2574 events) than those who disagreed (21.2% of 576 events) (OR = 9.8, 95% CI = 5.5, 17.3).

CONCLUSIONS

Adolescents' contraceptive behaviors were associated with reported intentions. However, approximately one half of coital events were not protected in women who agreed that they were committed to not getting pregnant. These women may represent a group at risk for unintended pregnancy.

Patterns of oral contraceptive pill-taking and condom use among adolescent contraceptive pill users

PURPOSE

Imperfect oral contraceptive pill (OCP) regimen adherence may impair contraceptive effectiveness. The purpose of this study was to describe daily adherence patterns of OCP use, to analyze OCP protection on an event level basis, and to examine pill-taking and condom use during method transitions.

METHODS

Women (n = 123, ages 14-17 years) completed quarterly interviews to classify OCP method choice into four categories: stable, initiated, stopped, and discordant use. Within each OCP category, daily diaries were used to assess occurrence of coitus, condom use, and patterns of day-to-day OCP use (i.e., consecutive days of OCP use reported with no more than two consecutive days of nonuse). A coital event was OCP protected if pills were used on both the day of the coitus and the day preceding.

RESULTS

There were 123 participants who reported at least some OCP use in 210 diary periods (average diary length = 75.5 days). Fifty-three participants categorized as stable users reported 87 diary periods: the average interval of consecutive OCP use in this group was 32.5 days. Among stable users, only 45% of coital events were associated with both OCP and condom use. Over one-fifth of coital events in all groups were protected by no method of contraception.

CONCLUSION

Dual use of OCP and barrier contraception remains an elusive goal. The time during OCP adoption or discontinuation is often unprotected by condoms. However, concurrent missed pills and condom nonuse increase pregnancy and infection risk even among stable OCP users. Understanding motivation for method usage may improve education and prevention techniques.

Ovarian follicular dynamics during conventional vs. continuous oral contraceptive use

OBJECTIVES

The purpose of this study was to characterize ovarian follicular and endometrial development during conventional vs. continuous oral contraceptive (OC) dosing regimens, to explore follicular development during the hormone-free interval (HFI) and to examine follicular development following OC discontinuation.

STUDY METHODS

A randomized clinical trial involving 36 clinically normal healthy women between the ages of 18 and 35 years (24.4 +/- 3.9, SEM). Transvaginal ultrasonography and blood sampling were done to ascertain ovarian function.

RESULTS

Fewer follicles > 4 mm developed during continuous vs. conventional OC use (p = .006). No dominant follicles developed during continuous OC use vs. eight dominant follicles (16.1 +/- 3.3 mm) during the conventional OC regimen. Two of eight (25%) dominant follicles ovulated. All dominant follicles began development during the HFI. Following discontinuation of OC use, ovulation took approximately 5 days longer when compared to natural cycles.

CONCLUSION

Continuous OC regimens more effectively prevent dominant follicle development and breakthrough ovulation. The slight delay in time to ovulation following OC discontinuation and natural cycles could be attributed to suppression of follicle wave activity.

Effective use of hormonal contraceptives

This systematic review examines evidence regarding when during the menstrual cycle a woman can initiate combined oral contraceptive (COC) use and what can be done if a woman misses COCs. We searched the MEDLINE and EMBASE databases for articles published from 1966 to March 2005 related to COC initiation and to the effects of late or missed COCs. We identified 11 studies related to COC initiation and 25 studies related to the effects of missed pills. Evidence from these studies suggested that taking hormonally active pills for 7 consecutive days prevents normal ovulation and that initiating COCs through Day 5 of the menstrual cycle suppresses follicular activity. Studies on the effects of missed COCs generally showed that the risk of ovulation is greatest when the pill-free interval lasts >7 days. Limitations of this body of evidence include small sample sizes that may not reflect variation in larger populations, lack of a standard measurement of ovulation and difficulty in discerning how ovulation resulting from late or missed COCs corresponds to the risk of conception.

Grossesses survenant sous contraception orale : les leçons de l'étude GRECO

OBJECTIVES

The GRECO study has collected data on pregnancies, regardless of their outcome, that occurred in women taking an oral contraceptive.

PATIENTS AND METHODS

The analysis concerned 551 women prospectively recruited in services of gynaecology or obstetrics, termination of pregnancy centres, family planning centres or consultations of gynaecology in France throughout 2002 and who were 12 weeks pregnant or less.

RESULTS

Contraception used during the cycle of conception was an estroprogestative combination in 88% of cases, a microprogestative in 8.7%, a macroprogestative in 0.9% or another type of pill in 2.4%. Progestatives were levonorgestrel 59.0%, gestoden 17.2%, desogestrel 4.7%, norethisterone acetate 2.9%, norgestimate 1.8%, cyproterone acetate 2.0%, norgestrel 1.6%. When asked about the potential cause of the oral contraceptive failure, 76.9% of women reported events such as missed pills which were the most frequent cause of failure (60.8% of failures and 80.1% of events, 2.7+/-2.7 missed pills), followed by vomiting and diarrhoea. 81.5% of women chose to terminate their pregnancy.

DISCUSSION AND CONCLUSION

The GRECO study, despite its limitations (retrospective collection of missed pills data, declaratory data) showed that missed pills, even once, were the most common reason for oral contraceptive failure. The most frequent decision was the termination of pregnancy.

Oral contraceptive use in young women is associated with lower bone mineral density than that of controls

Osteoporosis is a skeletal disease affecting 44 million Americans. A primary strategy to prevent osteoporosis is to develop a high peak bone mass in youth. Oral contraceptives (OCs) alter hormones in women and could affect bone mass development. Fifty percent of American women between the ages of 20 and 24 years use OCs. However, the interaction between OCs and skeletal mineralization is poorly understood. Our aim was to compare bone mass [bone mineral density (BMD)] of young women who had a history of OC use, with regularly menstruating controls. We recruited 98 women who were 18 to 25 years of age and had a history of OC use (n=44, 3.4+/-1.9 years of OC use) and controls (n=58). BMD at the hip, whole-body, and spine [anterior-posterior (AP) and lateral grams per square centimeter] was measured by dual-energy X-ray absorptiometry (DXA). Physical activity [in metabolic equivalents (METs)] was measured via questionnaire, and grip strength was evaluated with an isometric dynamometer. Groups were similar in body mass index (BMI), fat mass, grip strength, calcium intake and physical activity, but OC users were slightly older than controls (21.3+/-1.9 years vs 20.3+/-1.6 years, P<0.05). In analysis of covariance, controlled for age and BMI, controls had significantly greater BMD than OC users at the AP and lateral spine, femoral neck, greater trochanter, total hip, and whole body (P<0.05). We conclude that, in this cross-sectional analysis, oral contraceptive use by young women may compromise bone health during a time when mineral is still accruing.

Safety and efficacy of an extended-regimen oral contraceptive utilizing continuous low-dose ethinyl estradiol

OBJECTIVE

To assess the efficacy and safety of Seasonique, a 91-day extended-regimen oral contraceptive (OC) utilizing continuous low-dose ethinyl estradiol (EE) during the typical hormone-free interval.

METHODS

A multicenter, open-label, 1-year study of Seasonique [30 microg EE/150 microg levonorgestrel (LNG)] for 84 days followed by EE 10 microg for 7 days was conducted in sexually active, adult women of childbearing potential. All patients completed daily electronic diaries to monitor compliance and bleeding.

RESULTS

Method failure rate was 0.78 (Pearl index) and 0.64% (life table analysis). Cycle control and safety of the regimen were similar to that reported for other OCs.

CONCLUSION

This study demonstrates that Seasonique is effective, safe and well tolerated for the prevention of pregnancy.

20 mcg versus >20 mcg estrogen combined oral contraceptives for contraception

BACKGROUND

Concern about estrogen-related adverse effects has led to progressive reductions in the estrogen dose in combination oral contraceptives (COCs). However, reducing the amount of estrogen to improve safety also could result in decreased contraceptive effectiveness and unacceptable changes in bleeding patterns.

OBJECTIVES

To test the hypothesis that COCs containing </=20 mcg ethinyl estradiol (EE) perform similarly as those containing >20 mcg in terms of contraceptive effectiveness, bleeding patterns, discontinuation, and side effects.

SEARCH STRATEGY

We searched computerized databases (CENTRAL, MEDLINE, EMBASE, and POPLINE) from their inception to November 2003, searched the references of eligible trials, and wrote to oral contraceptive manufacturers to identify eligible trials.

SELECTION CRITERIA

English-language reports of randomized controlled trials that compare a COC containing </=20 mcg EE with a COC containing >20 mcg EE were eligible. We excluded studies where the interventions were designed to be administered for less than three consecutive cycles or to be used primarily as treatment for non-contraceptive conditions. Trials had to report on contraceptive effectiveness, bleeding patterns, trial discontinuation due to bleeding-related reasons or other side effects, or side effects to be included in the review.

DATA COLLECTION AND ANALYSIS

The primary reviewer evaluated all titles and abstracts located in the literature searches to determine whether they met the inclusion criteria. Two reviewers independently extracted data from the studies identified for inclusion. We wrote to the authors when clarifications or additional data were needed. Data were entered and analyzed with RevMan 4.2.

MAIN RESULTS

No differences were found in contraceptive effectiveness for the 11 COC pairs for which this outcome was reported. Several COCs containing 20 mcg EE resulted in higher rates of early trial discontinuation (overall and due to adverse events such as irregular bleeding) as well as increased risk of bleeding disturbances (both amenorrhea/infrequent bleeding and irregular, prolonged, frequent bleeding, or breakthrough bleeding or spotting) than their higher-estrogen comparison pills.

AUTHORS' CONCLUSIONS

While COCs containing 20 mcg EE may be theoretically safer, this review did not focus on the rare events required to assess this hypothesis. Data from randomized controlled trials are inadequate to detect possible differences in contraceptive effectiveness. Low-dose estrogen COCs resulted in higher rates of bleeding pattern disruptions. However, most trials compared COCs containing different progestin types, and changes in bleeding patterns could be related to progestin type as well as estrogen dose.

Faculty Statement from the CEU on a New Publication: WHO Selected Practice Recommendations for Contraceptive Use Update Missed pills: new recommendations

The World Health Organisation Selected Practice Recommendations for Contraceptive Use (WHOSPR) was first published in 2002 and provides evidence-based recommendations on how to use contraception effectively. The WHOSPR was adapted for UK use by the Faculty of Family Planning and Reproductive Heath Care (FFPRHC). The UK version is available on the FFPRHC website (www.ffprhc.org). Extensive field experience with the first edition of the WHOSPR highlighted to the WHO the need for revised recommendations for missed combined oral contraceptive pills (COCs). The WHOSPR was updated in 2004 and revised guidance on missed pills published. This guidance is now available on the WHO website (www.who.int/reproductive-health). The FFPRHC endorses the new recommendations from WHO on missed COCs for the following reasons: There is new evidence on which to base guidance. The WHOSPR follow a published and rigorous process for assessing the available evidence. The recommendations were developed by an international expert panel, with UK representation. Field experience shows a need for simple, harmonised guidance. This Statement summarises the revised WHOSPR evidence-based 'missed pill rules' in formats which we hope clinicians will find useful. We recognise that different individuals favour different styles for the presentation of information. Thus, both tabular and flow chart styles of summary are provided; these convey the same information but in different ways. The FFPRHC considers that the following statements may also serve as useful aides memoir for the 'missed pill rules': Whenever a woman realises that she has missed pills, the essential advice is 'just keep going'. She should take a pill as soon as possible and then resume her usual pill-taking schedule. Also, if the missed pills are in week three, she should omit the pill-free interval. Also, a back-up method (usually condoms) or abstinence should be used for 7 days if the following numbers of pills are missed: 'Two for twenty' (ie if two or more 20 microgram ethinylestradiol pills are missed). 'Three for thirty' (ie if three or more 30-35 microgram ethinylestradiol pills are missed). The fpa (Family Planning Association) has produced a revised COC user information sheet to reflect these changes; available from April 2005.

Follicular growth during contraceptive pill or vaginal ring treatment depends on the day of ovulation in the pretreatment cycle

BACKGROUND

The aim of this study was to investigate whether the day of ovulation and the duration of a pretreatment cycle were related to the degree of follicular growth during subsequent contraceptive treatment.

METHODS

This randomized, open-label study was performed in 40 healthy female volunteers, who were randomized by a computer-generated list after stratification for the ovulation day in a pretreatment cycle. They received two cycles of NuvaRing (21 subjects) or a combined oral contraceptive (COC) containing 30 microg ethinylestradiol and 150 microg levonorgestrel (19 subjects). Follicular diameter and serum hormone concentrations (FSH, LH, 17beta-estradiol, progesterone) were measured every third day. Data from treatment day 20 onwards were used for analysis.

RESULTS

In the NuvaRing users, subjects with short cycles and early ovulations in the pretreatment cycle developed larger follicles during treatment than subjects with longer cycles and late ovulations. In the COC users, subjects with early ovulations in the pretreatment cycle developed larger follicles during treatment.

CONCLUSIONS

The degree of follicular growth during treatment with a combined hormonal contraceptive is influenced by the duration of the pretreatment cycle and particularly by the duration of the follicular phase.

Plasma concentrations of endogenous hormones during one regular treatment cycle with a low-dose oral contraceptive and during two cycles with deliberate omission of two tablets

In this open, prospective, phase-I study we closely monitored levels of endogenous progesterone, 17beta-estradiol, luteinizing hormone (LH) and follicle stimulating hormone in six healthy women. We determined plasma concentrations every 1-3 days during one untreated baseline cycle and during the first treatment cycle with regular pill intake of an oral contraceptive containing 30 microg ethinylestradiol plus 75 microg gestodene. During the following two treatment cycles, two tablets were deliberately omitted (in cycle 2 on days 6/7 and in cycle 3 on days 11/12). All but possibly one volunteer ovulated in the untreated pre-cycle, as concluded from LH peaks followed by marked increases of progesterone. During the regular first treatment cycle and even after deliberate omission of two tables in treatment cycles 2 and 3, the progesterone and estradiol levels remained low, so that we concluded that no ovulation took place. However, two volunteers showed some sort of LH peak in the first regular treatment cycle and all women showed LH increases of > 40 microg/ml in at least one omission cycle. In ten out of 12 cycles, omissions of pill intake were followed by an episode of intermenstrual bleeding. In conclusion, we have shown that, after omission of two consecutive oral contraceptive tables, the endogenous hormone parameters did not provide evidence for ovulation. Although this provides confirmation of the robustness of this oral contraceptive towards non-compliance, the widely published practical recommendations should be followed.

Manipulation of the pill-free interval in oral contraceptive pill users: the effect on follicular suppression

OBJECTIVE

The purpose of this study was to compare follicular suppression that was produced by 3 different oral contraceptive regimens that differ by treatment in the pill-free interval.

STUDY DESIGN

In a university setting, 54 women were assigned randomly to receive either 20 microg ethinyl estradiol+100 microg levonorgestrel followed by 7 pill-free days, 20 microg ethinyl estradiol+150 microg desogestrel followed by 2 days of placebo then 10 microg ethinyl estradiol for 5 days, or 28 days of 20 microg ethinyl estradiol plus 150 microg desogestrel. Follicular suppression was evaluated by serial ultrasound scans and by serum and urinary hormone levels during a 2-month study period. Data were analyzed by nonparametric statistical tests.

RESULTS

There was a significant difference in follicle count among the 3 groups (P=.005). Women who were treated with a 7-day pill-free interval experienced the least suppression. Estrogen levels were more variable and led to an observation that overweight (body mass index, >25 kg/m(2)) was associated with reduced follicle suppression (relative risk, 1.6; 95% CI, 1.0, 2.7) and higher estrogen levels (relative risk, 5.3; 95% CI, 1.3, 21).

CONCLUSION

Contraceptive pill users who were treated with a 7-day pill-free interval demonstrated less follicular suppression than women who were supplemented with either estrogen alone or estrogen plus progestin. Overweight women were less suppressed than women of normal weight.

Ovarian follicular development during the use of oral contraception: a review

Over the past 40 years, alterations to the composition of oral contraceptives (OCs) have been made in attempts to reduce adverse effects and to improve patient compliance while maintaining contraceptive efficacy. However, there is growing evidence to indicate that reducing the estrogen dose to minimize adverse effects may have compromised the degree of hypothalamo-pituitary-ovarian suppression, particularly during the hormone-free interval (HFI) or following missed doses. Follicle development during OC use appears to occur in association with a loss of endocrine suppression during the HFI. This information provides a rationale for reducing or eliminating the HFI in OC regimens. There is also evidence for an increased risk of follicle development and ovulation in women who use delayed OC initiation schemes, such as the "Sunday Start" method. It is not currently known why some follicles ovulate during OC use while others regress or form anovulatory follicle cysts. Continued research about follicle development during OC use would provide insight into understanding the precise mechanisms of action underlying combined OCs, as well as those of continuous OC formulations and emergency contraceptive regimens.

FFPRHC Guidance (October 2003): First Prescription of Combined Oral Contraception

The Guidance provides information for clinicians on the steps to be taken before providing a woman with her first prescription for combined oral contraception. It updates and replaces previous Faculty Guidance. A key to the grades of recommendations, based on levels of evidence, is given at the end of this document. Details of the methods used by the Clinical Effectiveness Unit (CEU) in developing this Guidance, and evidence tables summarising the research basis of the recommendations, are available on the Faculty website (www.ffprhc.org.uk). Abbreviations used include: blood pressure (BP), body mass (BMI), bone mineral density (BMD), breakthrough bleeding (BTB), British National Formulary (BNF), combined oral contraception (COC), Committee on Safety of Medicines (CSM), confidence interval (CI), deep vein thrombosis (DVT), emergency contraception (EC), ethinyl oestradiol (EE), Faculty Aid to Continuing Professional Development Topics (FACT), Family Planning Association (fpa), follicule-stimulating homone (FSH), general practitioner (GP), intermenstrual bleeding (IMB), luteinising hormone (LT), microgram, myocardial infarction (MI), odds ratio (OR), oral contraception (OC), pulmonary embolism (PE), relative risk (RR), Scottish Intercollegiate Guideline Network (SIGN), sexually transmitted infection (STI), Summary of Product Characteristics (SPCs), venous thomboembolism (VTE), World Health Organization (WHO), WHO Medical Eligibility Criteria (WHOMEC), WHO Selected Practice Recommendations (WHOSPR).

Longitudinal changes in bone density in relation to oral contraceptive use

The primary aim of this 36-month prospective cohort study was to evaluate the association between use of oral contraceptives (OCs) and bone mineral density in reproductive-age women. The 36-month bone density (g/cm2) at the spine, hip and whole body and percent change from baseline (measured at 6-month intervals) were evaluated among 245 women 18-39 years of age; 89 were using OCs (median duration: 3.7 years at study entry) and 156 were not using any hormonal contraception. Before and after adjustment for covariates (baseline bone density, age, race, ever pregnant, exercise, body mass and calcium intake), women using OCs did not differ significantly from comparison women in percent change in bone density over 36 months or in absolute bone density at 36 months. All p-values for between-group differences were >0.55. In conclusion, within the limitations of this study, OCs did not appear to impact bone density over time in this cohort of reproductive-age women.

The effect of extending the pill-free interval on follicular activity: triphasic norgestimate/35 micro g ethinyl estradiol versus monophasic levonorgestrel/20 micro g ethinyl estradiol

This study was designed to evaluate follicular activity in women taking oral contraceptives with imposed imperfect compliance. After completing a 28-day cycle of either triphasic norgestimate/EE (NGM/EE) (Ortho Tri-Cyclen, Ortho-McNeil Pharmaceutical, Raritan, NJ) or monophasic levonorgestrel/EE (LNG/EE) (Alesse, Wyeth-Ayerst Laboratories, Philadelphia, PA), women were instructed to intentionally "miss" the first two active pills of the next pack. The first two tablets in the second treatment cycle were deliberately omitted, thereby extending the pill-free interval from 7 days to 9 days. Subjects were randomized to take NGM/EE (n = 40) or LNG/EE (n = 39) for two consecutive cycles. The mean maximum follicular diameter was significantly greater in women taking LNG/EE than in those taking NGM/EE (16.4 +/- 7.1 mm vs. 12.6 +/- 8.3 mm, p = 0.047). The LNG/EE group had significantly higher median serum estradiol concentrations compared to women taking NGM/EE on pill Days 10 [29.5 pg/mL (range: 10.0-540.0 pg/mL) vs. 2.5 pg/mL (range: 2.0-6.0 pg/mL), p < 0.001] and 14 [11.0 pg/mL (range: 2.0-416.0 pg/mL) vs. 2.0 pg/mL (range: 2.0-3.0 pg/mL), p = 0.001]. Two women in the NGM/EE group and three women in the LNG/EE group had at least one progesterone level > or =3 ng/mL; none of these women demonstrated a maximum follicular diameter >13 mm. Significantly greater follicular activity was observed after an extended pill-free interval in women taking LNG/EE compared to those taking triphasic NGM/EE. The clinical implications of these findings require further study.

Charcoal treatment and risk of escape ovulation in oral contraceptive users

Ovulatory potential was studied during the use of two oral contraceptive pill preparations, after repeated mid-cycle administration of activated charcoal. Eleven women used monophasic pills containing gestodene, 75 microgram, plus ethinyl oestradiol, 30 microgram, or norethisterone acetate, 1 mg, plus ethinyl oestradiol, 30 microgram, for 4 months each, in randomized order. During both pill treatments the third cycle was a control cycle, and during the fourth cycle of both pill types, 5 g of activated charcoal was ingested four times a day, starting 3 h after pill intake, on cycle days 12, 13 and 14. Ovarian activity was monitored by intravaginal ultrasonography of follicles and by measurements of serum concentrations of LH, FSH, oestradiol and progesterone throughout the control and charcoal-treatment cycles of both pill treatments. None of the women ovulated. Follicular activity seen in two women did not correlate with charcoal administration. It is concluded that the possible enterohepatic recirculation of gestodene and norethisterone is not of clinical importance. Repeated charcoal treatment, when administered 3 h after but at least 12 h before pill intake, can be used to treat diarrhoea in women taking oral contraceptives.

Ovulatory potential of preovulatory sized follicles during oral contraceptive treatment

The ovulatory potential of preovulatory follicles was studied in five women taking monophasic gestodene pills containing 20 micrograms of ethinyl estradiol. After one normal pill cycle, follicles were allowed to grow to 16 mm in diameter by deliberate extension of the pill-free period. Once the size of the leading follicle reached 16 mm, the women resumed oral contraceptives for the following 21 days to investigate whether ovulation can be inhibited by late onset of the pill. In addition, 100 micrograms of gonadotropin releasing hormone analog was given intravenously on the third pill day to induce ovulation. Follicular growth and activity were monitored by ultrasonography and by serum concentrations of ethinyl estradiol, progesterone, luteinizing hormone, and follicle stimulating hormone from the last pill day of the first cycle until the end of the second pill intake of 21 days. An increase in luteinizing hormone secretion started before intravenous administration of a gonadotropin releasing hormone analog in all women, eventually leading to ovulation in four of five women. One woman developed an unruptured follicle. Thus, the ovulatory potential of a 16-mm functional follicle cannot be inhibited by reintroduction of pills containing 20 micrograms ethinyl estradiol and 75 micrograms of gestodene.