Ovulation inhibition doses of progestins: a systematic review of the available literature and of marketed preparations worldwide

Oocyte competence is comparable between progestin primed ovarian stimulation with Norethisterone acetate (NETA-PPOS) and GnRH-antagonist protocols: A matched case-control study in PGT-A cycles

OBJECTIVE

To outline oocyte competence after progestin primed ovarian stimulation with Norethisterone acetate (NETA-PPOS) compared to conventional GnRH-antagonist protocol.

STUDY DESIGN

Retrospective matched case-control study involving advanced-maternal-age women undergoing ICSI with PGT-A. 89 NETA-PPOS were matched with 178 control patients based on maternal age and ovarian reserve biomarkers. Both groups underwent recombinant-FSH OS with GnRH-agonist ovulation trigger and collected ≥1 MII. In the study group, NETA (10 mg/day) was administered orally starting from day2 of the menstrual cycle. Euploid blastocyst rate per cohort of metaphase-II oocytes (EBR per MII) was the primary outcome. All other embryological and clinical outcomes were reported. Gestational age, birthweight and length were also assessed.

RESULTS

The EBR per MII was comparable among PPOS and control (13.9 % ± 19.3 % versus 13.3 % ± 17.9 %; the sample size allowed to exclude up to a 10 % difference). Blastocysts morphology and developmental rate were similar. No difference was reported for all clinical outcomes among the 61 and 107 vitrified-warmed euploid single blastocyst transfers respectively conducted. The cumulative live birth delivery rate per concluded cycles was also comparable (24.7 % versus 21.9 %). Neonatal outcomes were analogous.

CONCLUSIONS

Oocyte competence after NETA-PPOS and standard OS is comparable. This evidence is reassuring and, because of its lower cost and possibly higher patients' compliance, supports PPOS administration whenever the patients are indicated to freeze-all (e.g., fertility preservation, PGT-A, oocyte donation). More data are required about follicle recruitment, oocyte yield, gestational and perinatal outcomes. Randomized-controlled-trials are advisable to confirm our evidence.

Three new metabolites from the endophyte Fusarium proliferatum T2-10

One new cyclopeptide, cyclo-(L-Trp-L-Phe-L-Phe) (1), one new 2-pyridone derivative, fusarone A (3), and one new natural indole derivative, ethyl 3-indoleacetate (4), along with six known compounds were isolated from the endophytic fungus Fusarium proliferatum T2-10. The planar structures of three new compounds were identified by spectral methods including 1D and 2D NMR techniques, and the absolute configuration of compound 1 was elucidated by Marfey-MS method. In addition, all compounds were evaluated for their cytotoxic and antibacterial activities in vitro. Compound 2 showed remarkable cytotoxic activities against two human hepatoma cell lines SMMC7721 and HepG2 with IC50 values of 5.89 ± 0.74 and 6.16 ± 0.52 μM, and showed moderate antibacterial activities against Staphylococcus aureus and Enterococcus faecalis with MIC values of 7.81 and 15.62 μg/mL, respectively.

The benefits of estetrol addition to drospirenone for contraception

Ethinylestradiol and drospirenone combined oral contraceptive formulations have been marketed for >20 years. Drospirenone has antimineralocorticoid and anti-androgenic effects that may offer several health benefits. Recently, 2 new drospirenone-containing oral contraceptives entered the market, 1 as a progestin-only pill containing 4 mg drospirenone and the other as a combined oral contraceptive containing 15 mg estetrol and 3 mg drospirenone. Estetrol has a unique differential effect on nuclear and membrane estrogen α-receptors when compared with other estrogens, leading to low impact on the liver, breast, and hemostasis parameters and a beneficial effect on the endometrium, vagina, cardiovascular system, bone, and brain. Phase 3 clinical studies demonstrated that the Pearl Index (pregnancies per 100-woman-years) for drospirenone alone is 4.0 in the United States and 0.93 in the European Union and for the estetrol-drospirenone combination it is 2.65 and 0.44, respectively. Drospirenone alone demonstrates high rates of unscheduled bleeding and low rates of scheduled bleeding, whereas the estetrol-drospirenone combination demonstrates a predictable and regular bleeding profile for most users with a high stable rate of scheduled bleeding and a low rate of unscheduled bleeding, reported primarily as spotting only. The adverse event profiles and discontinuation rates owing to adverse events are comparable, and no clinically significant effects were observed on metabolic parameters with either product. Hemostatic assays for drospirenone do not fully evaluate all parameters although the testing that is available suggests negligible effects, whereas validated hemostatic assays demonstrate that the estetrol-drospirenone combination has limited impact on hemostasis. The introduction of 4 mg drospirenone and 15 mg estetrol with 3 mg drospirenone are valuable additions to the contraceptive market. Adding estetrol to 3 mg drospirenone provides advantages of contraceptive efficacy and a regular, predictable bleeding profile with minimal impact on hemostasis parameters.

Progestins of today and tomorrow

PURPOSE OF REVIEW

To review the current literature on the multiple types and uses of progestins in reproductive healthcare.

RECENT FINDINGS

Progestins for contraceptive use are available in multiple forms, with the ongoing development of transdermal, intravaginal, and male contraception formulations. Noncontraceptive use of progestins often overlaps with contraceptive indications, which allows for simultaneous multipurpose progestin use, especially in reproductive-aged patients. More studies are needed to determine contraceptive doses of progestins used for noncontraceptive purposes. Side effect profiles of progestins are dependent on their formulation and cross-reactivity with other steroid receptors. Development of newer progestins includes manipulating pharmacologic properties to avoid undesired side effects.

SUMMARY

Progestins have multiple uses in reproductive healthcare, including contraception, menstrual suppression, endometrial protection, and hormonal replacement therapy. The development of progestins for these indications can expand therapy for people with contraindications to estrogen-based hormonal therapy.

Hormone-based models for comparing menstrual cycle and hormonal contraceptive effects on human resting-state functional connectivity

Oral contraceptives (OCs) are widely used yet understudied given their potential for public health consequences. Emerging investigations scaling from single-subject, dense-sampling neuroimaging studies to population-level metrics have linked OCs to altered brain structure and function. Modeling the hypogonadal, hypergonadal, or mixed state effects of OCs in terms of their impact on hormone action in the brain is a valuable approach to synthesizing results across neuroimaging studies and comparing OC effects to companion findings from research on menstrual cycle phase effects on brain anatomy and function. Resting-state functional connectivity studies provide a powerful tool to evaluate the role of OCs on the intrinsic network connectivity that underlies multiple behavioral domains. The preponderance (but not consensus) of the current literature indicates that (1) as the menstrual cycle proceeds from a low to high progesterone state, prefrontal connectivity increases and parietal connectivity decreases; (2) OCs tend to mimic this connectivity pattern; therefore (3) OCs may produce a hyperprogestogenic state in the brain, in spite of overall reductions in endogenous steroid hormone levels. Alternative models are also considered.

Association of Progestogens and Venous Thromboembolism Among Women of Reproductive Age

OBJECTIVE

To evaluate associations between use of seven progestogens and incident acute venous thromboembolism (VTE) among women of reproductive age.

METHODS

This nested matched case-control study identified women aged 15-49 years from January 1, 2010, through October 8, 2018, in the IBM MarketScan databases, a nationwide sample of private insurance claims in the United States. After exclusions, 21,405 women with incident acute VTE (case group), identified by diagnosis codes, were matched 1:5 by year of birth and index date through risk set sampling to 107,025 women without prior VTE (control group). From lowest to highest systemic dose based on a modified hierarchy, progestogens studied were levonorgestrel-releasing intrauterine device (LNG-IUD), oral norethindrone, etonogestrel implant, oral progesterone, oral medroxyprogesterone acetate, oral norethindrone acetate, and depot medroxyprogesterone acetate (DMPA). Conditional logistic regression models adjusted for 16 VTE risk factors were used to estimate odds ratios and 99% CIs for incident acute VTE associated with current progestogen use compared with nonuse. The primary analysis treated each progestogen as a binary exposure. Dose, which varied for oral formulations, and chronicity were explored separately. Significance was set at P <.01 to allow for multiple comparisons.

RESULTS

Current use of higher-dose progestogens was significantly associated with increased odds of VTE compared with nonuse (oral norethindrone acetate: adjusted odds ratio [aOR] 3.00, 99% CI 1.96-4.59; DMPA: aOR 2.37, 99% CI 1.95-2.88; and oral medroxyprogesterone acetate: aOR 1.98, 99% CI 1.41-2.80). Current use of other progestogens was not significantly different from nonuse (LNG-IUD, etonogestrel implant, and oral progesterone) or had reduced odds of VTE (oral norethindrone). Sensitivity analyses that assessed misclassification bias supported the primary findings.

CONCLUSION

Among reproductive-aged women using one of seven progestogens, only use of norethindrone acetate and medroxyprogesterone acetate-considered higher-dose progestogens-was significantly associated with increased odds of incident acute VTE. The roles of progestogen type, dose, and indication for use warrant further study.

Special Considerations for Women of Reproductive Age on Anticoagulation

Anticoagulation poses unique challenges for women of reproductive age. Clinicians prescribing anticoagulants must counsel patients on issues ranging from menstruation and the possibility of developing a hemorrhagic ovarian cyst to teratogenic risks and safety with breastfeeding. Abnormal uterine bleeding affects up to 70% of young women who are treated with anticoagulation. As such, thoughtful clinical guidance is required to avoid having young women who are troubled by their menses, dose reduce, or prematurely discontinue their anticoagulation, leaving them at increased risk of recurrent thrombosis. Informed by a review of the medical literature, we present current recommendations for assisting patients requiring anticoagulation with menstrual management, prevention of hemorrhagic ovarian cysts, and avoiding unintended pregnancy. The subdermal implant may be considered a first-line option for those requiring anticoagulation, given its superior contraceptive effectiveness and ability to reliably reduce risk of hemorrhagic ovarian cysts. All progestin-only formulations-such as the subdermal implant, intrauterine device, injection, or pills-are generally preferred over combined hormonal pills, patch, or ring. Tranexamic acid, and in rare cases endometrial ablation, may also be useful in managing menorrhagia and dysmenorrhea. During pregnancy, enoxaparin remains the preferred anticoagulant and warfarin is contraindicated. Breastfeeding women may use warfarin, but direct oral anticoagulants are not recommended given their limited safety data. This practical guide for clinicians is designed to inform discussions of risks and benefits of anticoagulation therapy for women of reproductive age.

Contraception During Perimenopause: Practical Guidance

Climacteric is by no means in itself a contraindication to safe contraception. On the contrary, there are several conditions related to the perimenopause that could benefit from the use of modern contraceptives, mainly hormonal, with the goals of avoiding unintended pregnancies and giving further possible benefits beyond contraception (menstrual cycle control, a reduction of vasomotor symptoms and menstrual migraines, a protection against bone loss, a positive oncological risk/benefit balance). This narrative review aims to provide practical guidance on their possible use in this particular life stage, both short- and long-acting reversible contraceptives, and to assist clinicians for women transitioning from contraception to their menopausal years, including the possible initiation of postmenopausal hormone therapy. Comprehensive contraceptive counselling is an essential aspect of the overall health and wellbeing of women and should be addressed with each such patient irrespective of age.

Contraception Selection, Effectiveness, and Adverse Effects: A Review

IMPORTANCE

Many women spend a substantial proportion of their lives preventing or planning for pregnancy, and approximately 87% of US women use contraception during their lifetime.

OBSERVATIONS

Contraceptive effectiveness is determined by a combination of drug or device efficacy, individual fecundability, coital frequency, and user adherence and continuation. In the US, oral contraceptive pills are the most commonly used reversible method of contraception and comprise 21.9% of all contraception in current use. Pregnancy rates of women using oral contraceptives are 4% to 7% per year. Use of long-acting methods, such as intrauterine devices and subdermal implants, has increased substantially, from 6% of all contraceptive users in 2008 to 17.8% in 2016; these methods have failure rates of less than 1% per year. Estrogen-containing methods, such as combined oral contraceptive pills, increase the risk of venous thrombosis from 2 to 10 venous thrombotic events per 10 000 women-years to 7 to 10 venous thrombotic events per 10 000 women-years, whereas progestin-only and nonhormonal methods, such as implants and condoms, are associated with rare serious risks. Hormonal contraceptives can improve medical conditions associated with hormonal changes related to the menstrual cycle, such as acne, endometriosis, and premenstrual dysphoric disorder. Optimal contraceptive selection requires patient and clinician discussion of the patient's tolerance for risk of pregnancy, menstrual bleeding changes, other risks, and personal values and preferences.

CONCLUSIONS AND RELEVANCE

Oral contraceptive pills are the most commonly used reversible contraceptives, intrauterine devices and subdermal implants have the highest effectiveness, and progestin-only and nonhormonal methods have the lowest risks. Optimal contraceptive selection incorporates patient values and preferences.

Norethisterone and its acetate - what's so special about them?

INTRODUCTION

Progestogens (progestins) are widely used for contraception, in postmenopausal hormone therapy, and in treatment of abnormal uterine bleeding and endometriosis. Norethisterone (NET) and its acetate (NETA) differ from other progestogens by their partial conversion to ethinylestradiol (EE). We review their special characteristics and focus on the clinically relevant risk factors associated with estrogen action, such as migraine with aura and risk of thrombosis.

METHODS

Narrative review based on a medical literature (OvidMedline and PubMed) search.

RESULTS

NET converts to significant amounts of EE; 10-20 mg NET corresponds to 20-30 µg EE. The effects of NET on the endometrium are pronounced, making it a good choice for treating abnormal uterine bleeding, endometriosis, and endometrial hyperplasia. NET also has beneficial effects on bone mineral density and positive or neutral effects on cardiovascular health. Conversely, long-term use of NET is associated with a slightly increased breast cancer risk, and the risk of venous thromboembolism is moderately increased. This risk seems to be dose-dependent; contraceptive use carries no risk, but therapeutic doses might be associated with an increased risk. Studies suggest an association between combinations of EE and progestogens and ischaemic stroke, which in particular concerns women with migraine. No studies have, however, assessed this risk related to the therapeutic use of NET.

CONCLUSIONS

NET is a potent progestogen, especially when considering the endometrium. Its partial conversion to EE, however, is important to remember. Clinical consideration is required with women at high risk for either breast cancer or thromboembolism, or experiencing migraine with aura.

Progesterone - Friend or foe?

Estradiol is the "prototypic" sex hormone of women. Yet, women have another sex hormone, which is often disregarded: Progesterone. The goal of this article is to provide a comprehensive review on progesterone, and its metabolite allopregnanolone, emphasizing three key areas: biological properties, main functions, and effects on mood in women. Recent years of intensive research on progesterone and allopregnanolone have paved the way for new treatment of postpartum depression. However, treatment for premenstrual syndrome and premenstrual dysphoric disorder as well as contraception that women can use without risking mental health problems are still needed. As far as progesterone is concerned, we might be dealing with a two-edged sword: while its metabolite allopregnanolone has been proven useful for treatment of PPD, it may trigger negative symptoms in women with PMS and PMDD. Overall, our current knowledge on the beneficial and harmful effects of progesterone is limited and further research is imperative.

The effectiveness of quick starting oral contraception containing nomegestrol acetate and 17-β estradiol on ovulation inhibition: A randomized controlled trial

To determine the effectiveness of quick starting combined oral contraception (COC) contain 2.5 mg nomegestrol acetate and 1.5 mg estradiol (NOMAC/E2) comparing with 0.075 mg gestodene and 0.02 mg ethinyl estradiol (GS/EE) on ovarian ovulation inhibition rate, we conducted a non-inferiority randomized controlled trial involving 69 healthy female volunteers aged 18–40 years who had normal menstrual history and were randomized at a 2:1 ratio to take one pack of COC containing either NOMAC/E2 (study group) or GS/EE (control group) starting on menstrual cycle Day7–9. The ovarian activity was assessed by using Hoogland and Skouby grading. Forty-six and 23 participants were randomized to NOMAC/E2 and GS/EE groups, respectively. Baseline characteristics were similar between groups. No significant difference was observed between the study and control groups for ovulation inhibition rate (93.4% vs. 95.6%, risk difference: –2.2%, 95% CI: –13.1, 8.8), ovarian quiescence rate (91.2% vs. 91.2%, P = 1.000), persistent cyst rate (2.2% vs. 4.4%, P = 1.000), and ovulation rate (6.6% vs. 4.4%, P = 1.000). Quick starting COC during day7–9 of menstrual cycle can inhibit ovulation for more than 90%. The quick starting NOMAC/E2 is non-inferior to GS/EE for preventing ovulation and suppressing follicular growth.

Ovarian reserve markers in women using various hormonal contraceptives

Objectives: The aim of the study was to assess whether the ovarian reserve markers anti-Müllerian hormone (AMH) and antral follicle count (AFC) were lower among women using the progestin-only pill (POP) or levonorgestrel-releasing intrauterine system (LNG-IUS) and similar to the decrease observed in combined oral contraceptive (COC) pill users.Methods: This retrospective study comprised 565 hormonal contraceptive users (COC, POP, LNG-IUS or contraceptive vaginal ring) and 983 non-hormonal contraceptive users, who were seen in two Danish fertility assessment and counselling clinics between 2015 and 2019. Adjusted multiple regression analysis was used to examine the differences in AMH and AFC between hormonal and non-hormonal contraceptive users.Results: Compared with non-hormonal contraceptive users, AMH was 31.1% lower among COC users [95% confidence interval (CI) -39.6%, -25.9%; p < 0.001], 35.6% lower among POP users (95% CI -49.0%, -18.6%; p < 0.001) and 17.1% lower among LNG-IUS users (95% CI -31.4%, 0.002%; p = 0.052); no significant differences were seen among vaginal ring users. Compared with non-hormonal contraceptive users, AFC was 31.3% lower among COC users (95% CI -35.0%, -25.3%; p < 0.001) and 29.7% lower among POP users (-39.1%, -17.9%; p < 0.001); no significant differences were seen among LNG-IUS or vaginal ring users. Ovarian volume was more than 50% reduced among COC and vaginal ring users (p < 0.001) but was unchanged among POP and LNG-IUS users.Conclusion: Assessment of ovarian reserve markers among users of all types of hormonal contraception should be interpreted cautiously and the type of contraceptive method considered.

Dydrogesterone: pharmacological profile and mechanism of action as luteal phase support in assisted reproduction

The pharmacological and physiological profiles of progestogens used for luteal phase support during assisted reproductive technology are likely to be important in guiding clinical choice towards the most appropriate treatment option. Various micronized progesterone formulations with differing pharmacological profiles have been investigated for several purposes. Dydrogesterone, a stereoisomer of progesterone, is available in an oral form with high oral bioavailability; it has been used to treat a variety of conditions related to progesterone deficiency since the 1960s and has recently been approved for luteal phase support as part of an assisted reproductive technology treatment. The primary objective of this review is to critically analyse the clinical implications of the pharmacological and physiological properties of dydrogesterone for its uses in luteal phase support and in early pregnancy.

Pharmacodynamics of combined estrogen-progestin oral contraceptives 3. Inhibition of ovulation

INTRODUCTION

Following a historical overview, the ovulation-inhibiting effect of various orally administered estrogen-progestin combinations (combined oral contraceptives [COCs]) are examined for their components alone or in the various combined formulations. Special emphasis is given to products containing natural estrogens. Areas covered: Inhibition of ovulation with progestins alone; estrogens alone; various progestins in combination with ethinyl estradiol; various progestins in combination with natural estrogens (estradiol, estradiol valerate, and estetrol). Expert commentary: The original idea to achieve ovulation blockage through the administration of steroid hormones involved the use a progestogen (both progesterone and its synthetic homologous). The ability of a progestin to inhibit ovulation depends on the type of compound and on its dosage and a difference of more than 20-fold in activity exists between compounds utilized today in COCs. Initially, the estrogenic component was present only because it contaminated the first progestin utilized. It was soon found that an estrogen is necessary for proper cycle control. It was also found that the estrogen acts synergistically in inhibiting ovulation. For almost half a century, most COCs contained ethinyl estradiol. Today, also natural estrogens are being employed. Inhibition of ovulation was complete with all early high dose preparations. Decreasing dosage allowed some ovarian activity to occur, occasionally leading to a mature follicle. Even in this situation, defective corpus luteum formation assured contraceptive protection.

A strategic action framework for multipurpose prevention technologies combining contraceptive hormones and antiretroviral drugs to prevent pregnancy and HIV

OBJECTIVE

Multipurpose prevention technologies (MPTs) are an innovative class of products that deliver varied combinations of human immunodeficiency virus (HIV) prevention, other sexually transmitted infection (STI) prevention, and contraception. Combining separate strategies for different indications into singular prevention products can reduce the stigma around HIV and STI prevention, improve acceptability of and adherence to more convenient products, and be more cost-effective by addressing overlapping risks.

METHODS

This article outlines a strategic action framework developed as an outcome of a series of expert meetings held between 2014 and 2016. The meetings focused on identifying opportunities and challenges for MPTs that combine hormonal contraception (HC) with antiretroviral drugs into single products. The framework aims to present an actionable strategy, by addressing key research gaps and outlining the key areas for progress, to guide current and future HC MPT development.

RESULTS

We identified eight primary action areas for the development of impactful HC MPTs, and includes aspects from epidemiology, pharmacology, clinical trial design, regulatory requirements, manufacturing and commercialisation, behavioural science, and investment needs for research and development.

CONCLUSION

Overall, the challenges involved with reconciling the critical social-behavioural context that will drive MPT product use and uptake with the complexities of research and development and regulatory approval are of paramount importance. To realise the potential of MPTs given their complexity and finite resources, researchers in the MPT field must be strategic about the way forward; increased support among policy-makers, advocates, funders and the pharmaceutical industry is critical.

Hormonal regulation of oviductal glycoprotein 1 (OVGP1; MUC9) in the rhesus macaque cervix

BACKGROUND

Macaques are outstanding animal models for the development of new contraceptives. In women, progestin-only contraceptives often fail to block ovulation and are believed to act by altering cervix physiology. Herein, we assessed oviductal glycoprotein 1 (OVGP1) in the macaque cervix as a marker for progestogen action.

MATERIALS

Rhesus macaques were treated with estradiol (E₂ ), E₂ plus progesterone (P), and E₂ plus levonorgestrel (LNG), a contraceptive progestin. Samples consisted of archived blocks of midcervix mucosa (epithelium and lamina propria) and fresh epithelial cells collected non-invasively by cytobrush. OVGP1 was assayed by quantitative real-time PCR and localized by immunocytochemistry.

RESULTS

OVGP1 transcript was maximal after E₂ and reduced after treatment with E₂  + P (P < .05). LNG also reduced OVGP1 expression (P < .05). OVGP1-specific staining localized to epithelial cells, and transcript was quantifiable in cytobrush collected samples.

CONCLUSIONS

OVGP1 expression in cytobrush samples of macaque cervix provides a non-invasive indicator of contraceptive progestin action.

The use of progestogen-only pill in migraine patients

Migraine is a debilitating neurovascular disorder which is estimated to affect 18% of women and 6% of men. Two main forms of this neurological disorder must be considered: Migraine without Aura and Migraine with Aura. Migraine without aura often has a strict menstrual relationship: the International Headache Society classification gives criteria for Pure Menstrual Migraine and Menstrually Related Migraine. The higher prevalence of migraine among women suggests that this sex difference probably results from the trigger of fluctuating hormones during the menstrual cycle. Safe and effective contraception is essential for all women of childbearing age, but Combined Oral Contraceptives have been associated with worsening of attacks and cardiovascular risk in these patients. We analyzed characteristics, effects and benefits of progestogen-only pill, a possible alternative for contraception in women with migraine.

A primer on the hormone-free interval for combined oral contraceptives

BACKGROUND

The dosing, schedules, and other aspects of combined oral contraceptive (COC) design have evolved in recent years to address a variety of issues including short- and long-term safety, bleeding profiles, and contraceptive efficacy. In particular, several newer formulations have altered the length of the hormone-free interval (HFI), in order to minimize two key undesired effects that occur during this time: hormone-withdrawal-associated symptoms (HWaS) and follicular development.

OBJECTIVE

This primer reviews our current understanding of the key biological processes that occur during the HFI and how this understanding has led to changes in the dosing and schedule of newer COC formulations.

MAIN MESSAGE

In brief, HWaS are common, underappreciated, and a likely contributor to COC discontinuation; because of this, shortening the HFI and/or supplementing with estrogen during the progestin-free interval may provide relief from these symptoms and improve adherence. A short HFI (with or without estrogen supplementation) may also help maintain effective follicular suppression and contraceptive efficacy, even when the overall dose of estrogen throughout the cycle is low.

CONCLUSIONS

Taken together, the available data about HWaS and follicular activity during the HFI support the rationale for recent COC designs that use a low estrogen dose and a short HFI. The availability of a variety of COC regimens gives physicians a range of choices when selecting the most appropriate COC for each woman's particular priorities and needs.

Effects of chronic oestradiol, progesterone and medroxyprogesterone acetate on hippocampal neurogenesis and adrenal mass in adult female rats

Both natural oestrogens and progesterone influence synaptic plasticity and neurogenesis within the female hippocampus. However, less is known of the impact of synthetic hormones on hippocampal structure and function. There is some evidence that the administration of the synthetic progestin, medroxyprogesterone acetate (MPA) is not as beneficial as natural progesterone and can attenuate oestrogen-induced neuroprotection. Although the effects of oestradiol have been well studied, little is known about the effects of natural and synthetic progestins alone and in combination with oestradiol on adult neurogenesis in females. In the present study, we investigated the effects of chronic oestradiol, progesterone, MPA and the co-administration of each progestin with oestradiol on neurogenesis within the dentate gyrus of adult ovariectomised female rats. Twenty-four hours after a bromodeoxyuridine (BrdU; 200 mg/kg) injection, female rats were repeatedly administered either progesterone (1 or 4 mg), MPA (1 or 4 mg), oestradiol benzoate (EB), progesterone or MPA in combination with EB (10 μg), or vehicle for 21 days. Rats were perfused on day 22 and brain tissue was analysed for the number of BrdU-labelled and Ki67 (an endogenous marker of cell proliferation)-expressing cells. EB alone and MPA + EB significantly decreased neurogenesis and the number of surviving BrdU-labelled cells in the dorsal region of the dentate gyrus, independent of any effects on cell proliferation. Furthermore, MPA (1 and 4 mg) and MPA + EB treated animals had significantly lower adrenal/body mass ratios and reduced serum corticosterone (CORT) levels. By contrast, progesterone + EB treated animals had significantly higher adrenal/body mass ratios and 1 mg of progesterone, progesterone + EB, and EB significantly increased CORT levels. The results of the present study demonstrate that different progestins alone and in combination with oestradiol can differentially affect neurogenesis (via cell survival) and regulation of the hypothalamic-pituitary-adrenal axis. These findings have implications for women using hormone replacement therapies with MPA for both neuroprotection and stress-related disorders.

Hormonal contraception in women with migraine: is progestogen-only contraception a better choice?

A significant number of women with migraine has to face the choice of reliable hormonal contraception during their fertile life. Combined hormonal contraceptives (CHCs) may be used in the majority of women with headache and migraine. However, they carry a small, but significant vascular risk, especially in migraine with aura (MA) and, eventually in migraine without aura (MO) with additional risk factors for stroke (smoking, hypertension, diabetes, hyperlipidemia and thrombophilia, age over 35 years). Guidelines recommend progestogen-only contraception as an alternative safer option because it does not seem to be associated with an increased risk of venous thromboembolism (VTE) and ischemic stroke. Potentially, the maintenance of stable estrogen level by the administration of progestins in ovulation inhibiting dosages may have a positive influence of nociceptive threshold in women with migraine. Preliminary evidences based on headache diaries in migraineurs suggest that the progestin-only pill containing desogestrel 75μg has a positive effect on the course of both MA and MO in the majority of women, reducing the number of days with migraine, the number of analgesics and the intensity of associated symptoms. Further prospective trials have to be performed to confirm that progestogen-only contraception may be a better option for the management of both migraine and birth control. Differences between MA and MO should also be taken into account in further studies.