Dehydroepiandrosterone (DHEA) supplementation in diminished ovarian reserve (DOR)

Casson et al. did not claim direct DHEA effects on DOR ovaries. They, instead, suggested that DHEA supplementation appears to augment ovarian stimulation with gonadotropins in poor responders, resulting in improved oocytes yields [1]. Likely due to their small study population, their paper failed to elicit follow up until previously noted index patient, five years later, rediscovered their publication [10].

Like the paper by Casson et al [1], the index patient's experience initially suggested that improvements from DHEA supplementation were primarily quantitative (better oocyte yields), and even greater than originally reported by the Baylor group. Moreover, the index patient's longitudinal experience over nine IVF cycles also demonstrated continuous improvements in oocyte (and embryo) numbers with increasing length of DHEA supplementation.

Cumulative DHEA effects over time, in turn, suggested possible effects on follicle recruitment or, as previously reported by the Baylor group, a synergistic effect between DHEA and gonadotropins [8]. One, therefore, at that point could conclude that DHEAsupplementation, potentially, may not only offer improving oocyte numbers, but also improving ovarian reserve (OR). Since the Baylor group had only attempted to address the problem of poor response to ovarian stimulation [1], this conclusion represented a significant expansion of the concept underlying the utilization of DHEA.

Concentrating on DHEA effects on OR significantly changed concepts since OR, defined by size and quality of remaining follicles within ovaries [14, 15], presumed DHEA effects on ovaries beyond just one stimulation cycle. DHEA would then not only have to impact oocyte and embryo numbers but also oocyte and embryo quality and, therefore, ultimately, pregnancy success. In absence of prospectively randomized studies, and with use of other study formats, conclusions, of course, have to be drawn cautiously.

The first 25 DOR patients, supplemented with DHEA in paired analysis of pre- and post-DHEA cycles, confirmed significant increases in oocytes and embryo numbers, previously observed in the index patient [16]. They, however, also demonstrated improved embryo quality, including better embryo grades, average embryo scores and, most importantly, better embryo numbers available for transfer.

Since low embryo numbers are a principle characteristic of DOR, this observation further supported the hypothesis that DHEA may also positively affect pregnancy chances. Uniformity of quantitative and qualitative IVF outcome improvements (Table 1) also encouraged such thought.

In a subsequently larger cohort of 89 DOR patients, supplemented with DHEA for up to four months, and in 101 controls, DHEA patients demonstrated shorter time to pregnancy and higher pregnancy rates (cumulative clinical pregnancies, 28.1% vs. 10.9%; 95% CI 1.2-11.8; p < 0.05), despite prognostically more favorable controls (more oocytes, P < 0.01; normal day-3 embryos, P < 0.05; and more embryos transferred, P < 0.05). Moreover, study patients were also older (41.6 ± 0.4 vs. 40.0 ± 0.4 years) [17].

DHEA thus improved all outcome parameters, even though patient selection was biased against such findings. This study for the first time also suggested primacy of egg and embryo quality over egg and embryo quantity.

[Though not part of here reported literature review, we find it noteworthy that, concomitantly, Edward Ryan's Toronto West Fertility Center had started utilizing DHEA in women with DOR. This group in subsequent years in a number of abstracts reported significantly improved clinical pregnancy rates in hundreds of IVF and insemination cycles, using varying ovarian stimulation protocols (Ryan E, Personal communication, 2009). In cooperation with Robert F Casper from Toronto's Mount Sinai Hospital and University of Toronto, they more recently reported on 47 patients with prior clomiphene citrate failures who, supplemented with 75 mg DHEA daily for at least 60 days prior to inseminations, with stimulation by either clomiphene citrate or letrozole in combination with FSH. Controls were 46 women, matched by age and baseline FSH, without supplementation. DHEA patients demonstrated significantly higher antral follicle counts, significantly improved pregnancy rates (29.8 vs. 8.7%; CI 1.3-14.8) and live births (21.3% and 6.5%, respectively) [18], numbers remarkably similar to those earlier reported from our center [17].]

From Turkey, Sönmezer and associates reported on 19 "poor responders" to ovarian stimulation [19]. After DHEA, this group experienced significant decreases in cycle day-3 estradiol levels, increased large follicle numbers, MII oocytes, top quality day-2 and day-3 embryos, reduced cycle cancellations and improved pregnancy rates per patients (47.4% vs. 10.5%, P < 0.001) and per embryo transfer (44.4% vs. 0.0%, P < 0.01).

Wiser and associates most recently presented the first prospectively randomized study of DHEA supplementation with DOR (ClinicalTrial.gov ID # NCT01145144) (12). While small (17 study and 16 control patients), DHEA patients demonstrated improved embryo quality over time (P = 0.04), with increasing length of DHEA supplementation and significantly higher live birth rates (23.1 vs. 4.0%; P = 0.05).

While in our opinion the study was underpowered since the authors counted 55 IVF cycles in 33 patients, thus including repeat IVF cycles without evidence of adjustments via the randomization schedule, it, nevertheless, has to be considered a milestone in view of prior failed attempts to conduct such studies.

When DOR patients were separated into those with age-dependent DOR and women with so-called premature ovarian aging (POA) [17], also given the acronym occult primary ovarian insufficiency (OPOI) (20), DHEA supplementation proved similarly effective in both groups, though POA patients did mildly better. The beneficial effects of DHEA increased with length of DHEA supplementation, documented by increasing discrepancy in cumulative pregnancy rates between the groups over time (Figure 2) [17].

This confirmed initial observations in the index patient [10]. DHEA effects occur relatively quickly (apparently within ca. 2 months) but peak only after 4-5 months of DHEA supplementation. Our center, therefore, supplements DHEA for at least six weeks prior to IVF cycle starts, though even longer pretreatment may be used in younger patient.

Surprising numbers of spontaneously conceived pregnancies during these waiting periods suggest that DHEA, alone, can in DOR patients raise fecundity [17].

POA/OPOI has to be differentiated from outright premature ovarian failure (POF), also called primary ovarian insufficiency (POI) [20]. Mamas and Mamas claimed a small case series of five alleged POF/POI patients, who spontaneously conceived while on DHEA [21].

Intriguing in concept, the report should, however, be viewed with caution since three of the five reported patients do not qualify for a diagnosis of POF/POI and, likely, more resemble POA/OPOI patients [22]. Mamas and Mamas, however, reiterated their claim [23] and in a personal communication advised us of additional pregnancies in DHEA supplemented POF/POI patients (Mamas L, Personal communication, ESHRE Annual Meeting, Amsterdam, The Netherlands, July 2009).

Anecdotally, we recently recorded, after 4 months of DHEA supplementation, a spontaneous pregnancy in a 38 year old woman with POF/POI (highest recorded FSH 100.0 mIU/mL). A registered clinical trial of DHEA in POF/POI patients (ClinicalTrials.gov ID#NCT00948857) is currently underway at our center but is not expected to yield results for at least two more years.

In her last IVF cycle the index patient offered to have 10 of her embryos investigated for aneuploidy [10].

Only one was euploid. Limitations in current methods of preimplantation genetic screening (PGS) restrict applications of PGS in women with DOR since small embryo numbers mostly preclude PGS [24]. In 2007, a small pilot study demonstrated in 100 percent of DHEA treated but only 53 percent of control IVF cycles at least one euploid embryo (p < 0.05) [25]. Patient selection was again biased against DHEA since DHEA supplemented women were older than controls and, therefore, should have demonstrated higher aneuploidy rates.

Though offering statistically significant results, study results of this pilot also had to be viewed cautiously because of small study numbers and potential biases and patient selection. Better numbers and superior selection of controls in a more recently published study permitted for more reliable results, which confirmed significant decreases in aneuploidy after DHEA supplementation [26].

In absence of adequate PGS numbers, close statistical associations between aneuploidy and spontaneous pregnancy loss [27] offered an indirect way to investigate the issue. In a combined effort with Edward Ryan's Toronto center, enough DHEA pregnancies had been established to allow for a statistically robust analysis of miscarriage rates. As at least 60 percent of miscarriages are associated with chromosomal abnormalities [27], a DHEA effect on ploidy should be statistically reflected in lower miscarriage rates, and this was, indeed, confirmed [28].

Depending on statistical method utilized, pregnancy loss after DHEA supplementation was reduced by 50 to 80 percent in comparison to national U.S. IVF pregnancy rates, a conclusion further strengthened by the following: (i) Miscarriage rates in Toronto and New York were practically identical (15.2 and 15.0%, respectively); (ii) The U.S. national IVF registry, used as control population, in contrast to DHEA patients, included only relatively few DOR patients. Women with DOR are known to demonstrate significantly increased miscarriage rates in comparison to other infertility etiologies [29].

Makeup of controls, therefore, biased the study against findings favoring DHEA supplementation; (iii) The combined miscarriage rate of 15.1 percent in DHEA pretreated patients at both IVF centers is reflective of spontaneous miscarriage rates for normal, fertile populations [30]; (iv) DHEA effects on miscarriage rates were small under age 35 years but increased progressively after that age (Figure 3).

Increasing aneuploidy with advancing female age, of course, would suggest increasing effectiveness of DHEA with advancing female age. A beneficial DHEA effect on embryo ploidy, therefore, appears likely, and seems to increase with age.

Recent data further support these conclusions (Figure 4): Miscarriage rates, even with most severe DOR, are very low after DHEA supplementation. Between non-detectable anti-Müllerian hormone (AMH) of <0.1 and 0.4 ng/mL they remain equal to those seen in normally fertile women, increase at AMH 0.41 - 1.05 ng/mL to over 50 percent of all pregnancies established, representing the expected rate in DOR patients [29], only to fall off again above AMH 1.05 ng/mL [31]. With miscarriage rates, likely due to DHEA supplementation, being very low under AMH 0.4 and above 1.05 ng/mL, the question arises why this effect is not also seen at AMH levels of 0.41-1.05 ng/mL?

Trying to find an answer, we investigated 39 spontaneous pregnancies in DOR patients on DHEA, conceived before they reached their first IVF cycle. Figure 4 depicts miscarriage rates of spontaneous in comparison to IVF pregnancies, demonstrating that spontaneous pregnancies experienced at all low AMH levels almost identically high miscarriage rates around approximately 50 percent of all pregnancies established. They, thus, demonstrate expected pregnancy loss rates for DOR patients [29], and do not seem to benefit from DHEA supplementation like IVF pregnancies.

Spontaneous pregnancies were, of course, conceived after shorter exposure to DHEA than IVF pregnancies since, as noted above, our center's DOR patients are at least for six weeks on DHEA supplementation before an IVF cycle is initiated. Patients who conceive spontaneously on DHEA during this "waiting period," therefore, by definition, had shorter DHEA exposure times. This observation then leads to the conclusion that shorter exposure times may be enough to raise fecundity but may not suffice to positively affect ploidy and miscarriage rates.

AMH levels are predictable of treatment outcomes after DHEA utilization [31, 32]. Table 2 summarizes how AMH levels relate to chance of conception and live births in IVF pregnancies: Even with complete absence of detectable AMH, an approximately five percent pregnancy chance per IVF cycle can be obtained. Since miscarriage rates are very low, pregnancy and live birth rates are very close. Outcomes remain the same up to AMH 0.4 ng/mL, when clinical pregnancy chances approximately double. Live birth rates remain, however, unchanged since at AMH 0.41-1.05 ng/mL spontaneous pregnancy wastage increases. Above those AMH levels pregnancy chances greatly improve and miscarriage risk recedes once again to much lower levels [31].

AMH 1.05 ng/mL, thus, represents a distinct point of separation between poorer and better live birth chances: Up to AMH 1.05 ng/mL the chance of live birth per treatment cycle is only approximately 5 percent. Above that, chances are significantly improved [31].

AMH increases in parallel to length of DHEA supplementation, and this increase is more pronounced in younger POA than older DOR patients [32] (Figure 5). Moreover, improvements in AMH are statistically highly predictive of pregnancy success [32] but do not yet allow for accurate prediction of who will and will not conceive with DHEA supplementation. AMH responses to DHEA, however, facilitate proper informed consent, particularly important in view of recent ethics guidelines on fertility treatments in poor prognosis patients [33].

Except for the previously noted studies by the Baylor group, few other pharma studies have address DHEA utilization, and those were usually restricted to postmenopausal women [34]. Building on the Baylor group's work, the index patient supplemented with micronized DHEA. She utilized over-the-counter products, which have been found inconsistent [35]. Though products are now, likely, improved, we primarily utilize pharmaceutical grade, compounded DHEA, by prescription at a dosage of 25 mg TID. Other authors, including Wiser et al in their recently published clinical trial [12], have used the same dosage of DHEA.

No studies on maximal dosaging of DHEA have, however, been reported, nor have delivery systems been compared. The Baylor group demonstrated distinct advantages from micronized and orally delivered DHEA [6].

Side effects at these dosages are small and rare, and primarily relate to androgen effects.

They include oily skin, acne vulgaris and hair loss. More frequently, patients comment on improved energy levels and better sex drive. In over 1,000 patients supplemented with DHEA, we did not encounter a single complication of clinical significance. A recent paper from Israel reported a posttraumatic seizure after one month of DHEA supplementation in attempts to improve oocytes yields [36]. Except for the anecdotal association, there appears no clinical significance to this report. Even long-term therapy of DHEA, in similar dosages as described here, has been demonstrated safe [37].

DHEA was recently listed amongst drugs with "orphan indications" in fertility therapy [38]. Our center, nevertheless, requires a DHEA-specific informed consent before treatment start.

Two other indications for DHEA supplementation are currently still under investigation in randomized, placebo controlled trials. Those are unexplained infertility (ClinicalTrials.gov ID#NCT00650754) and POF/POI (ClinicalTrials.gov ID# NCT00948857).

How DHEA improves OR, IVF parameters, pregnancy chances and decreases miscarriage rates is, ultimately, still unknown. Improved embryo ploidy may, at least in part, explain improvements in miscarriage rates, spontaneous pregnancies and pregnancies after IVF since this would suggest a method of pharmacological embryo selection.

Hodges et al suggested that treatments can be developed which will reduce the risk of age-related aneuploidy by influencing meiotic chromosome segregation [39]. Major disturbances in chromosome alignments on the meiotic spindle of oocytes (congression failure), responsible for aneuploidy, result from the complex interplay of signals regulating folliculogenesis, and increase the risk of non-disjunction errors. Discussed in more detail below, DHEA may, indeed, represent a first such treatment!

Other DHEA effects have, however, also to be considered: The Baylor group suspected increased ovarian IGF-1 to be responsible for observed DHEA effects [1, 8]. IGF-1, indeed, appears reduced in poor responders [40].

Androgens, in general, may enhance ovarian function: Already a few decades ago, androgens were in the mouse reported to increase follicle recruitment [41]. Increasing intrafollicular androgens augments granulose cell AMH and inhibin-B production [42].

Androgen receptors have been described in ovarian stroma and granulose cells of primordial follicles, primary follicles and at more advanced stages of folliculogenesis [43]; and ovarian androgens but not estrogens correlate with systemic inflammation during ovarian stimulation with gonadotropins [44].

Frattarelli and Peterson reported that day three testosterone levels below 20 ng/dL are associated with poorer IVF pregnancy rates [45]. They later reported an association with IVF stimulation parameters but not with pregnancy chance [46]. Iranian investigators recently reported that testosterone on day 14 after embryo transfer is predictive of pregnancy chance [47]. Lossl et al published contradictory papers, one claiming [48] and one refuting [49] that treatment with aromatase inhibitors (increasing androgens) improves embryo quality. Contradictory results have also been reported by French investigators in regards to short-term transdermal testosterone administration, with Massin et al reporting no benefit [50], and the Balasch's group in two publications stressing beneficial effects on ovarian resistance [51, 52]. The most recent study on the subject by Kim et al demonstrated that transdermal testosterone appears to improve ovarian response to stimulation and IVF outcome in low responders [53].

The, likely, most important study in support of essential androgen effects on follicle development and normal female fertility was recently, however, reported by Sen and Hammes [13]. These two authors were encouraged towards their study by previously reported observations in global androgen receptor knockout (ARKO) female mice, characterized by reduced androgen signaling, and subfertility. The mice also demonstrate defective folliculogenesis, decreased antral follicle counts and corpora lutea, exhibit higher granulose cell apoptosis, are resistant to ovarian stimulation with gonadotropins and often develop POF.

While androgen excess in animal and human experience has widely been associated with excessive and unregulated follicle formation, Sen and Hammes suspected that androgen signaling via androgen receptors may actually be important for normal follicle development and function. Since androgen receptors are widely expressed in different cell types, they decided to determine which androgen receptor - expressing cells contribute to ovarian function and fertility in female ARKO mice.

Using this elegant mouse model they concluded that almost all reproductive phenotypes they observed in global ARKO mice can be explained by lack of androgen receptor expression in granulose cells. Granulosa cell - specific androgen receptors, indeed, appear to promote preantral follicle growth and to prevent follicle atresia. The authors, therefore, concluded that androgen receptors (and by extension androgens) are essential for normal follicle development and female fertility [13].

IVF has revolutionized infertility care since it offers tools to maximize pregnancy chances while minimizing multiple pregnancy risks [54]. Even in association with DOR IVF has radically changed the clinical outlook, with pregnancy and live birth rates in women at even advanced reproductive ages constantly improving [31, 32, 55]. In the US women above age 40, now, represent the most rapidly growing age group giving birth [55].

Since young women with normal age-appropriate OR conceive quickly, POA and/or DOR patients, due to their lower pregnancy chances, disproportionally accumulate in infertility centers, needing more IVF cycles. The mean age of newly presenting patients at our center during 2009 was above 39.5 years. Premature or age-dependent DOR represented close to 90 percent of IVF cycle activity (Figure 6). DOR is, therefore, assuming increasing clinical importance, and potentially effective clinical approaches, like DHEA, are attracting wide attention.

Pharmaceuticals, stimulating ovaries, have been at the center of clinical and research interests in reproductive medicine for the last five decades. All agents developed and/or investigated affect follicle maturation, though only during final stages, the so-called gonadotropin-sensitive last two weeks. Here reviewed DHEA effects, in contrast, appear to affect folliculogenesis at much earlier stages.

If confirmed, these observations on DHEA could open ovarian stimulation to radically new horizons, for the first time directing pharmacological interventions towards earlier stages of in vivo follicle maturation.

Declining female fecundity with advancing age is based on diminishing follicle numbers and deteriorating egg quality [14, 15, 56]. While declines in follicle numbers are undisputed, the here presented DHEA experience raises, however, questions about the widely held understanding that declining egg quality with advancing female age is caused by aging oocytes.

Young women with prematurely DOR exhibit most typical signs of ovarian aging, such as elevated FSH, low AMH and ovarian resistance to stimulation, but do not demonstrate increased aneuploidy [57]. Their oocytes thus, quite obviously, are functionally not behaving "old" enough to lead to aneuploidy, while oocytes from older women, indisputably, demonstrate increased aneuploidy [27, 29].

We previously noted that DHEA supplementation apparently significantly reduces these age-related increases in aneuploidy [25, 26], and, therefore, also reduces age-associated increases in miscarriages [28, 31]. In absence of healthy and genetically normal oocytes both of these findings are inconceivable. DHEA is, therefore, either able to revert "older," already damaged oocytes, into "younger" oocytes, in itself a rather unlikely proposition, or one has to conclude that, contrary to current dogma [15, 56], oocytes in their resting stages within unrecruited primordial follicles do not really age.

Once recruited, they, however, enter age-dependent ovarian environments where follicle maturation takes place. These ovarian environments can be of different quality and will, uniformly, deteriorate as women age. As proposed by Hodges et al, these environments affect segregation processes during meiosis, giving rise to increased aneuploidy at older ages. Hodges and associates, however, also pointed out that these envrironments, and with it aneuploidy and miscarriage rates, may be open to pharmacologic manipulation [39].

Here presented DHEA data, therefore, support the concept that ovarian environments, but not resting oocytes, age as women grow older. Under such a concept here described DHEA effects are perfectly understandable. DHEA levels, indeed, peak in humans between ages 20 and 30 years, and then decline by approximately 2 percent per year, to reach nadirs of 10 to 20 percent around age 80 years [58].

In some women, aneuploidy may, thus, simply, represent a reversible DHEA deficiency. Others may lack yet to be determined components of healthy ovarian environments and, therefore, may benefit from other supplementations.

Proven correct, one can expect a significant expansion of the female's reproductive lifespan as science learns how to reconstitute ovarian environments, mimicking conditions of younger ages. Since even menopausal ovaries still contain follicles and oocytes [14], at least theoretically, childbirth may be expandable into the 50s.

In the Squirrel monkey, older animals, immediately prior to cessation of reproduction, still demonstrate an abundance of well-differentiated granulosa cells [58]. Assuming that unrecruited oocytes maintain their youth and that aged ovarian environments can be rejuvenated, smaller, but healthier, egg cohorts may, indeed, allow for pregnancy into surprisingly advanced female ages.

DHEA may, therefore, represent a first compound in a new category of pharamacological agents with potential to "rejuvenate" ovarian environments. Following a similar concept, Bentov et al., based on the known loss of mitochondrial functions with advancing age, recently suggested the use of mitochondrial nutrients, like coenzyme Q10 (CoQ10), after demonstrating that CoQ10 increases oocytes numbers in older mice [59]. Androgens positively affect mitochondrial function [60].

A better understanding of differences in ovarian environment between younger and older women will be needed to discover additional beneficial pharmacological agents. The technology for such studies is being developed [61].