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 multiple small collections of fluid (subcapsular microcysts) that are arranged like a “string of pearls” immediately below the ovarian surface (capsule).interspersed by an overgrowth of ovarian connective tissue (stroma). 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.
Women with PCOS are often at increased risk that ovarian stimulation with gonadotropins will result in the development of severe ovarian hyperstimulation syndrome (OHSS), a life-endangering condition that is often accompanied by a profound reduction in egg “competency” and on fertilization often yield an inordinately high percentage of “incompetent” embryos which have a reduced potential to propagate viable pregnancies.
Concern and even fear that their PCOS patients will develop of OHSS often leads the treating RE to take measures aimed at reducing the risk of this life-endangering condition. One such measures is to “trigger” egg maturation prematurely in the hope of arresting further follicular growth and the other, is to initiate the “trigger” with a reduced dosage of hCG (i.ed. 5,000U rather than the usual 10,000U of of Pregnyl/Profasi/Novarel, to use or 250mcg rather than 500mcg of Ovidrel or to supplant the hCG “trigger” with a Lupron “trigger” which causes a prompt LH surge from the woman’s pituitary gland to take place. While such measures do indeed reduce the risk of OHSS to the mother, this often comes at the expense of egg quantity and “competency”. Fewer than the anticipated number of eggs are harvested and those that are retrieved are far more likely to be “immature” and chromosomally abnormal (aneuploid”), or “immature” , thereby significantly compromising IVF outcome.
Against this background, It is my considered opinion that when it comes to performing IVF in women with PCOS, the most important consideration must be the selection and proper implementation of an individualized or customized ovarian stimulation protocol. Thereupon, rather than prematurely initiating the “trigger” to arrest further follicle growth, administering a reduced dosage of hCG or “triggering with a GnRH agonist (e.g. Lupron/Buserelin) that can compromise egg “competency”….. use of one of the following techniques will often markedly reduce the risk of OHSS while at the same time protecting egg quality:
- PROLONGED COASTING…my preferred approach: My preferred approach is to use a long pituitary down-regulation protocol coming off the BCP which during the last 3 days is overlapped with the agonist, Lupron/Buserelin/Superfact. The BCP is intended to lower LH and thereby reduce stromal activation (hyperthecosis) in the hope of controlling LH-induced ovarian androgen (predominantly, testosterone) production and release. I then stimulate my PCOS patients using a low dosage of recombinant FSH-(FSHr) such as Follistim/Gonal-F/Puregon. On the 3rd day of such stimulation a smidgeon of LH/hCG (Luveris/Menopur) is added. Thereupon, starting on day 7 of ovarian stimulation, I perform serial blood estradiol (E2) and ultrasound follicle assessments, watching for the number and size of the follicles and the blood estradiol concentration [E2]. I keep stimulating (regardless of the [E2] until 50% of all follicles reach 14mm. At this point, provided the [E2] reaches at least >2,500pg/ml, I stop the agonist as well as gonadotropin stimulation and track the blood E2 concentration daily. The [E2] will almost invariably increase for a few days. I closely monitor the [E2] as it rises, plateaus and then begins to decline. As soon as the [E2] drops below 2500pg/ml (and not before then), I administer a “trigger” shot of 10,000U Profasi/ Novarel/Pregnyl or 500mcg Ovidrel/Ovitrel. This is followed by an egg retrieval, performed 36 hours later. Fertilization is accomplished using intracytoplasmic sperm injection (ICSI) because “coasted” eggs usually have little or no cumulus oophoris enveloping them and eggs without a cumulus will not readily fertilize naturally. Moreover, they also tend to have a “hardened” envelopment (zona pellucida), making spontaneous fertilization problematic in many cases. All fertilized eggs are cultured to the blastocyst stage (up to day 5- 6 days) and thereupon are either vitrified and preserved for subsequent transfer in later hormone replacement cycles or (up to 2) blastocysts are transferred to the uterus, transvaginally under transabdominal ultrasound guidance. The success of this approach depends on precise timing of the initiation and conclusion of “prolonged coasting”. If started too early, follicle growth will arrest and the cycle will be lost. If commenced too late, too many follicles will be post-mature/cystic (>22mm) and as such will usually harbor abnormal or dysmature eggs. Use of “Coasting” almost always prevents the development of severe OHSS, optimizes egg/embryo quality and avoids unnecessary cycle cancellation. If correctly implemented, the worst you will encounter is moderate OHSS and this too is relatively uncommon.
- MULTIPLE FOLLICLE ASPIRATION: In some cases, in spite of best effort, you inadvertently find mean follicle size to exceed 16mm, thereby leaving too little time to implement “coasting”. On other occasions, “coasting” fails to effectively lower the [E2} below 2,500pg/ml within 3 days. In such case the number of developing follicles can effectively and drastically reduced (culled) through selective transvaginal aspiration prior to initiating the “trigger” with 10,000U hCG. This will almost invariably be accompanied by a rapid and significant drop in the plasma estradiol concentration along with a drastic reduction in the risk of OHSS occurring without significantly compromising egg/embryo quality. Upon completing surgical follicular reduction, the surviving follicles can be allowed to continue their full development, at which point the hCG “trigger” can be implemented. The drawback associated with this approach is that it unfortunately interjects an additional surgical intervention into an already complex and stressful situation.
- EMBRYO FREEZING AND DEFERMENT OF EMBRYO TRANSFER (ET): OHSS is always a self-limiting condition. In the absence of continued exposure to hCG, symptoms and signs as well as the risk of severe complications will ultimately abate. Thus, in the absence of pregnancy, all symptoms, signs and risks associated with OHSS will disappear within about 10-14 days of the hCG trigger. Conversely, since early pregnancy is always accompanied by a rapid and progressive rise in hCG , the severity of OHSS will increase until about the 9th or tenth gestational week whereupon a transition from ovarian to placental hormonal dominance occurs, the severity of OHSS rapidly diminishes and the patient will be out of risk. Accordingly, in cases where in spite of best effort to prevent OHSS, the woman develops symptoms and signs of progressive overstimulation prior to planned ET, all the blastocysts should be vitrified and cryostored for FET in a subsequent hormone replacement cycle. In this way women with OHSS can be spared the risk of the condition spiraling out of control.