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Understanding Polycystic Ovarian Syndrome (PCOS) and the Need to Customize Ovarian Stimulation Protocols

by Dr. Geoffrey Sher on November 8, 2015

Polycystic ovary syndrome (PCOS) is a common hormonal system disorder among women affecting between 5% and 10% of women of reproductive age worldwide.  Women with PCOS may have enlarged ovaries that contain small collections of fluid — called follicles — located in each ovary as seen during an ultrasound. The condition is characterized by abnormal ovarian function (irregular or absent periods, abnormal or absent ovulation and infertility), androgenicity (increased body hair or hirsutism, acne) and increased body weight –body mass index or BMI. The ovaries of women with PCOS characteristically contain multiple micro-cysts often arranged like a “string of pearls” immediately below the ovarian surface (capsule).interspersed by an overgrowth of ovarian connective tissue (stroma).

PCOS is one of the most common causes of menstrual irregularities, infertility, and hirsutism, Despite an enormous effort to define its cause, the etiology of PCOS remains unclear, and there is no definite cure at this time. PCOS is clearly a heterogeneous disorder which often has a familial (genetic) basis. Infertility associated with PCOS has been attributed to numerous factors, including dysfunctional gonadotropin pituitary secretion, peripheral insulin resistance, elevated adrenal and/or ovarian androgen (male hormone) levels, and dysfunction of several growth factors. Women with this condition are often obese and insulin resistant. The compensatory hyperinsulinemia further stimulates ovarian androgen production which may be detrimental to egg maturation and there is a clear link between the degree of insulin resistance and anovulation. PCOS is also a significant long-term health risk for women, thus necessitating vigilance through regular annual examinations (non-insulin dependent diabetes mellitus, hypertension, hypercholesterolemia, cardiovascular disease and endometrial cancer). Whereas PCOS-related infertility is usually manageable through the use of fertility drugs, lifestyle changes (diet and exercise) remain a mainstay of long-term therapy. More recently, ovulation rates, circulating androgens, pregnancy rates and perhaps even first-trimester miscarriage rates have been shown to improve when insulin sensitizers like metformin are used to correct the underlying insulin resistance.

Most patients with PCOS are young and have excellent pregnancy rates with oral clomiphene. Those that require more aggressive treatments with injectable medications probably represent a subgroup of PCOS patients with severe ovarian dysfunction. These women often have explosive response to gonadotropins which can result in serious complications like Severe Ovarian Hyperstimulation Syndrome (OHSS…see below) and high order multiple births. In those women, the ability to perform “prolonged coasting” (see below) and selectively transfer fewer embryos during IVF offers a clear advantage over standard gonadotropin injections.

Egg quality in PCOS

The potential for a woman’s eggs to undergo orderly maturation, successful fertilization and subsequent progression to “good quality embryos” is in large part genetically determined. However, the expression of such potential is profoundly susceptible to numerous influences, especially intra-ovarian hormonal changes during the pre-ovulatory phase of the cycle. Proper follicular stimulation as well as precise timing of egg maturation with LH (Luteinizing Hormone) or hCG (human chorionic gonadotropin) is crucial to optimal egg maturation, fertilization and ultimately embryo quality. Both pituitary gonadotropins, LH and FSH (follicle stimulating hormone) play a pivotal but different role in follicular development. The action of FSH is mainly directed toward granulosa cell (cells lining the inside of the follicle) proliferation and estrogen production (E2). LH, on the other hand, acts primarily on the ovarian stroma (the connective tissue that surrounds the follicle) to produce androgens. While small amounts of ovarian androgens, such as testosterone, enhance egg and follicle development, over-exposure to them can have a deleterious effect. Furthermore, excessive ovarian androgens can also compromise estrogen-induced endometrial growth and development.

Suppressing pituitary secretion of LH with gonadotropin releasing hormone (GnRH) agonists such as Lupron®, is particularly useful in PCOS. In that condition, serum LH levels are elevated, leading to stromal overgrowth, follicular arrests (so-called cysts) and high levels of androgens synthesis. It is therefore not surprising that these follicles often yield poorly developed (“immature”) eggs” at the time of egg retrieval (ET) and that “poor egg/embryo quality”, inadequate endometrial development and high miscarriage rates are common features of this condition. However, contrary to popular belief, this is not due to an intrinsic deficit in “egg quality”. Stimulation protocols geared toward optimizing follicle and egg development and avoiding over exposure to androgens correct these problems ad result in pregnancy rates similar to those of non-PCOS women. Whereas the overuse of LH-containing preparations such as Menopur® and Luveris® further aggravates this effect. In conclusion, to maximize ultimate oocyte maturation, we strongly recommend against the exclusive use of such products in PCOS patients, preferring FSH-dominant products such as Folistim®, Gonal F® or Bravelle® over a period of at least 9 days following pituitary suppression with Lupron®.

PCOS women often have a family history of diabetes and demonstrable insulin resistance (evidenced by high blood insulin levels and an abnormal 2-hour glucose tolerance test).This underlying Diabetes mellitus tendency could play a role in the development of PCOS and contribute to the development of obesity, an abnormal blood lipid profile, and a predisposition to coronary vascular disease. Women with PCOS are slightly more at risk of developing uterine, ovarian and possibly also breast cancer in later life and accordingly should be evaluated for these conditions on a more frequent basis than would ordinarily be recommended to non-PCOS women.

Most women with PCOS either do not ovulate at all or they ovulate irregularly. As a consequence thereof they in addition usually experience delayed, absent or irregular menstruation. In addition, an inordinate percentage of the eggs produced by PCOS women following ovulation induction, tend to be chromosomally abnormal (aneuploid). Rather than being due to an intrinsic egg defect being inherent in PCOS women, the poor egg quality more than likely the result of over-exposure to male  hormones (predominantly, testosterone) produced by the ovarian stroma. These two factors (ovulation dysfunction and poor egg quality) are the main reasons for the poor reproductive performance (infertility and an increased miscarriage rate) in PCOS women.

PCOS patients are at an inordinate risk of severely over-responding fertility drugs, both oral varieties (e.g. Clomiphene, Serophene & Femara) and especially the injectables (e.g. Follistim, Puregon, Gonal F, Menopur and Bravelle) by forming large numbers  ovarian follicles. This can lead to life endangering complications associated with sever ovarian hyperstimulation (OHSS). In addition PCOS women receiving fertility drugs often experience multiple ovulations putting them at  severe risk (40%+)  of high order multiple pregnancy (i.e. triplets or greater) with often devastating consequences.


1) Hypothalamic-pituitary-PCOS: This is the commonest form of PCOS and is  often genetically transmitted and is characteristically  associated with a blood concentration of Luteinizing Hormone (LH) that is uncharacteristically much higher than  the Follicle Stimulating Hormone (FSH) level (FSH is normally higher than the LH concentration) as well as high-normal or  blood androgen ( male) hormone  concentrations (e.g. androstenedione, testosterone and dehydroepiandrosterone -DHEA).Hypothalamic-pituitary-ovarian  PCOS is also often associated with insulin resistance and in about 40%-50% of the cases.

2) Adrenal PCOS: Here the excess of male hormones are derived from overactive adrenal glands rather than from the ovaries. Blood levels of testosterone and/or androstenedione raised but here, but here, the blood level of dehydroepiandrosterone (DHEAS) is also raised, clinching the diagnosis.

3) Severe pelvic adhesive disease secondary to severe endometriosis, chronic pelvic inflammatory disease and/or extensive pelvic surgery: Women who have this type of PCOS tend to less likely to hyperstimulate in response to ovulation induction . Their. DHEAS is also is not raised.


Hypothalamic-pituitary-/ovarian PCOS: Ovulation induction with fertility drugs such as clomiphene citrate, Letrozole (Femara) or gonadotropins, with or without intrauterine insemination (IUI) is often highly successful in establishing pregnancies in PCOS women. However, IVF is fast becoming a treatment of choice (see below).

In about 40% of cases, 3-6 months of oral Metformin (Glucophage) treatment results in a significant reduction of insulin resistance, lowering of blood androgen levels, an improvement in ovulatory function, and/or some amelioration of androgenous symptoms and signs.

Surgical treatment by “ovarian drilling” of the many small ovarian cysts lying immediately below the envelopment (capsule) of the ovaries, is often used, but is less successful than alternative non-surgical treatment and is only temporarily effective. The older form of surgical treatment, using ovarian wedge resection is rarely used any longer as it can produce severe pelvic adhesion formation.

Adrenal PCOS is treated with steroids such as prednisone or dexamethasone which over a period of several weeks will suppress adrenal androgen production, allowing regular ovulation to take place spontaneously. This is often combined with clomiphene, Letrozole and/or gonadotropin therapy to initiate ovulation.

PCOS attributable to Pelvic Adhesive Disease is one variety which often is associated with compromised ovarian reserve, a raised FSH blood level and ovarian resistance to fertility drugs. In many such cases, high dosage of gonadotropins (FSH-dominant) with “estrogen priming” will often elicit an ovarian response necessary for successful ovulation induction and/or IVF. Neither steroids nor Metformin are helpful in the vast majority of such cases.

PCOS women undergoing ovulation induction usually release multiple eggs following the hCG trigger and are thus at inordinate risk of twin or higher order multiple pregnancies. They are also at risk of developing OHSS.  Many now believe that IVF should be regarded as a primary and preferential treatment for PCOS. The reason is that it is only through this approach that the number of embryos reaching the uterus can be controlled and in this manner the risk of high-order multiples can be minimized and it is only in the course of IVF  treatment that a novel treatment method  known as “prolonged coasting” ( see below) which prevents OHSS, can be implemented


As indicated above, there is an inordinate propensity for women with PCOS to hyper-respond to gonadotropin fertility drugs and in the process produce large numbers of ovarian follicles. If left unchecked this can lead to OHSS, a potentially life endangering condition. The onset of OHSS is signaled by the development of a large number of ovarian follicles (usually more than 25 in number). This is accompanied by rapidly rising plasma estradiol (E2) levels, often exceeding 3000pg/ml within 7 or 9 days of stimulation, often rapidly peaking above 6,000 pg/ml prior to hCG administration. When this happens, the risk of OHSS developing is above 80%.

Symptoms and signs of OHSS include: abdominal distention due to fluid collection (ascites), fluid in the chest cavity (hydrothorax), rapid weight gain (of a pound or more per day) due to tissue fluid retention, abdominal pain, lower back ache, nausea, diarrhea, vomiting, visual disturbances such as blurred vision and spots in front of the eyes (scotomata), a rapidly declining urine output, cardiovascular collapse and failure of blood to clot which sometimes results in severe bruising (echymosis) and frank bleeding.  These symptoms and signs may appear before pregnancy can be diagnosed. If pregnancy occurs, the condition is likely to worsen progressively over a period of 3-5 weeks whereupon it rapidly resolves spontaneously over a few days. If no pregnancy occurs, the symptoms and signs all disappear spontaneously within 10-12 days of the hCG injection.

When increasing fluid collection in the abdominal cavity (ascites) starts to compromise breathing raising the head of the bed rose slightly by placing a 4-6 inch block at the base of each head post and using a few additional pillows, will sometimes help ameliorate the problem. In cases where this does not help or symptoms become severe, all or most of the fluid can readily and safely be drained through t transvaginal sterile needle aspiration (vaginal paracentesis-performed once or sometimes twice a week) can be performed once or twice weekly . The problem will usually self corrects within 10-12 days of the hCG shot if pregnancy does not occur or, by the 8th week of pregnancy.

Urine output should be monitored daily to see if it drops below about 500ml a day (about two cups and a half). A chest X-ray, to evaluate for fluid collection in the chest and around the heart should be done weekly along with blood tests for hematocrit, BUN, electrolytes, creatinine, platelet count and fibrin split products (FSP). If indicated on the basis of a deteriorating clinical situation, hospitalization might be needed for close observation and if necessary, to provide intensive care.

In all case of OHSS, the ovaries will invariably be considerably enlarged. This is irrelevant to the final outcome, unless ovarian torsion (twisting of the ovary on its axis), an extremely rare complication occurs. The latter would usually require surgical emergency surgical intervention.

It is important to know that symptoms and signs of OHSS are severely aggravated by rising hCG levels. Thus such patients should not receive additional hCG injections. 

Does PCOS cause poor egg/embryo quality? It is an undeniable fact that women with PCOS undergoing IVF are commonly found to have poorly developed (“dysmorphic”) eggs, with reduced fertilization potential and yielding “poor quality embryos”. However, in the author’s opinion (which admittedly runs contrary to popular opinion), this is unlikely to be due to an intrinsic deficit in egg quality. Rather, it more likely relates to   intra-ovarian hormonal changes brought about by hyperstimulation and which compromise egg development.  This effect, in the author’s opinion, can often be significantly reduced through implementation of an individualized or customized   ovarian stimulation protocols that minimize exposure of the developing follicles and eggs to excessive LH-induced ovarian androgens. This can be best achieved by limiting the use of LH-containing gonadotropins such as Menopur through selective institution of “prolonged coasting” (see below).

In the past, the onset of OHSS, heralded by the presence of large numbers of developing ovarian follicles and rapidly rising plasma estradiol levels often led the treating physician to prematurely administer hCG in an attempt to abruptly arrest the process and prevent escalation of risk to the patient. However the premature administration of hCG, while abruptly arresting further proliferation of estrogen producing granulosa cells in the follicles, unfortunately also prematurely arrests egg development. Since the ability of an egg to achieve optimal maturation upon hCG triggering is largely predicated upon it having achieved prior optimal development, the untimely administration of hCG which triggers meiosis, probably increases the risk of numerical chromosomal abnormalities (aneuploidy) of the egg. This in turn would lead to reduced fertilization potential, poor egg/embryo quality and low embryo implantation potential.

In women with PCOS the connective tissue that surrounding the follicles (ovarian stroma) is often characteristically overgrown (stromal hyperplasia). It is the stroma that produces androgens (mainly testosterone) in response to LH. It is this, coupled with the fact that PCOS women also often have elevated blood LH concentrations (see above) results in the excessive production of androgen hormones, which is so characteristic in PCOS. While excessive exposure of developing eggs to ovarian androgens compromises follicle and egg growth it also impairs endometrial response to estrogen, which could explain the common finding of poor endometrial thickening in many PCOS women undergoing IVF.


The obvious remedy for these adverse effects on egg and endometrial development is to employ stimulation protocols that limit ovarian over-exposure to LH and allowing the time necessary for the follicles/eggs to develop optimally, prior to administering hCG through the judicious implementation of   “Prolonged coasting” (PC).


In the early 90’s we were the first to report on “prolonged coasting” (PC), a novel approach that protects egg quality while preventing the development of OHSS. PC has since, gained widespread acceptance as a method of choice for preventing OHSS and has established itself as the “standard of care”. It involves withholding gonadotropin therapy while continuing the administration of the GnRHa and waiting until the plasma estradiol concentration drops below 2,500 pg/ml. Thereupon hCG is administered. In such cases, regardless of the number of developed follicles or the number of eggs retrieved, these women rarely, if ever develop OHSS. It has been reported that while PC virtually eliminates the risk of life-endangering complications associated with OHSS, there are reports in the literature that “the price to pay with PC” is often a poorer fertilization rate and   reduced embryo implantation potential, compromising the pregnancy”. It is the author’s opinion an experience in the development of PC that egg/embryo quality deficit likely has  little to do with the process of PC, itself and can be  explained as follows:  When  PC is initiated too early, follicle growth and development may cease (as evidenced by the estradiol level plateauing or falling immediately, rather than showing an initial continued increase), and when  PC is started  too late, the follicles will often become cystic, measuring >21mm by the time the estradiol level falls below the safe threshold of 250000pg/ml, and so harbor dysmorphic  eggs. Thus precise timing of the initiation of PC is critical. It should in pact be initiated preemptively in all cases when there are more than 25 follicles and the plasma estradiol reaches or exceeds 2,500pg/ml in association, provided that at least 50% of the follicles measuring 14-16mm in mean diameter. Not a day sooner or a day later. If PC is initiated with precise timing, it will usually be followed by a further progressive rise in the estradiol concentration. After a few days, the estradiol level will plateau and then it will start to fall (often rapidly). The temptation to trigger with hCG before the estradiol level falls below 3000picogtrams per milliliter must be resisted …even if the level falls below 1,000pg/ml by the time hCG is given.

Since when using agonist ( Cetrotide/Ganirelix/Orgalutron) pituitary suppression throughout the stimulation phase with gonadotropins, the plasma estradiol level often under expressed follicle growth, this method of pituitary blockade should not be used in cases ( such as with PCOS) where PC might be required.,

Prolonged coasting prevents canceled cycles and with it, canceled dreams.

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