Junctional zone thickening: an endo-myometrial unit disorder.

Adenomyosis is a disease defined by histopathology, mostly of hysterectomy specimens, and classification is challenged by the disagreement of the histologic definition. With the introduction of Magnetic Resonance Imaging (MRI) and two- and three-dimensional ultrasound, the diagnosis of adenomyosis became a clinical entity. In MRI and US, adenomyosis ranges from thickening of the inner myometrium or junctional zone to nodular, cystic, or diffuse lesions involving the entire uterine wall, up to a well-circumscribed adenomyoma or a polypoid adenomyoma. The absence of an accepted classification and the vague and inconsistent terminology hamper basic and clinical research. The sub-endometrial halo seen at US and MRI is a distinct entity, differing from the outer myometrium by its increased nuclear density and vascular structure. The endometrium and the sub-endometrial muscularis or archimetra are of Müllarian origin, while the outer myometrium is non-Mullerian mesenchymal. The junctional zone (JZ) is important for uterine contractions, conception, implantation, and placentation. Thickening of the JZ can be considered inner myometrium adenomyosis, with or without endometrial invasion. Changes in the JZ should be considered a different entity than myometrial clinically associated with impaired conception, implantation, abnormal uterine bleeding, pelvic pain and obstetrical outcome. Pathology of the basal endometrium and JZ is a separate entity and should be identified as an endo-myometrial unit disorder (EMUD).

Diagnosis and treatment of early-stage endometriosis by Transvaginal Hydro laparoscopy.

Background: Transvaginal Hydro Laparoscopy (THL) is known as a minimal invasive procedure allowing endoscopic exploration of the female pelvis. Objective: To evaluate the possibilities of the THL as a tool for early diagnosis and treatment of minimal endometriosis. Materials and Methods: A retrospective study of a consecutive series of 2288 patients referred for fertility problems to a tertiary centre for reproductive medicine was undertaken. Mean duration of infertility was 23.6 months (SD ±11-48), mean age of patients was 31.25 (SD± 3.8y). With normal findings at clinical and ultrasound examination patients underwent, as part of their fertility exploration, a THL. Main outcome measures: Evaluation of feasibility, identified pathology and pregnancy rate. Results: Endometriosis was diagnosed in 365 patients (16%); the localisation was higher on the left side (n=237) than on the right side (n=169). Small endometriomas, with diameters between 0.5 and 2 cm, were present in 24.3% (right side in 31, left side 48 and bilateral 10). These early lesions were characterised by the presence of active endometrial like cells and a pronounced neo-angiogenesis. Destruction of the endometriotic lesions with bipolar energy resulted in an in vivo pregnancy rate (spontaneous/IUI) of 43.8% (CPR after 8 months: spontaneous 57.7%; IUI/AID 29.7%). Conclusion: THL allowed in a minimally invasive way an accurate diagnosis of the early stages of peritoneal and ovarian endometriosis with the possibility of offering treatment with minimal damage. What is new?: This is the largest series reporting the usefulness of THL for the diagnosis and treatment of peritoneal and ovarian endometriosis in patients without obviously visible preoperative pelvic pathology.

The severity and frequency distribution of endometriosis subtypes at different ages: a model to understand the natural history of endometriosis based on single centre/single surgeon data.

Background and Objective: to study the natural history of endometriosis. Materials and methods: the analysis of all women (n=2086) undergoing laparoscopy for pelvic pain and endometriosis between 1988 and 2011 at University Hospital Gasthuisberg. Main outcome measures: the severity of subtle, typical, cystic and deep endometriosis in adult women, with or without a pregnancy, as estimated by their pelvic area and their volume. Results: the number of women undergoing a laparoscopy increased up to 28 years of age and decreased thereafter. Between 24 and 44 years, the severity and relative frequencies of subtle, typical, cystic and deep lesions did not vary significantly. The number of women younger than 20 years was too small to ascertain the impression of less severe lesions. The severity of endometriosis lesions was not less in women with 1 or more previous pregnancies or with previous surgery. There was no bias over time since the type and severity of endometriosis lesions remained constant between 1988 and 2011. Conclusions: severity of endometriosis does not increase between 24 and 44 years of age, suggesting that growth is limited by intrinsic or extrinsic factors. Severity was not lower in women with a previous pregnancy. What is new: considering the time needed for lesions to become symptomatic together with the diagnostic delay, the decreasing number of laparoscopies after age 28 is compatible with a progressively declining risk of initiating endometriosis lesions after menarche, the remaining women being progessively less susceptible.

Systematic use of transvaginal hydrolaparoscopy as a minimally invasive procedure in the exploration of the infertile patient: results and reflections.

BACKGROUND: The aim of this study was to evaluate the added value of transvaginal hydrolaparoscopy (THL) in the investigation of the infertile patient. METHODS: A retrospective cohort study, based on records from 01/09/2006 to 30/12/2019 was undertaken in a tertiary care infertility centre. THL was performed in 2288 patients. These were patients who were referred for endoscopic exploration of the female pelvis as part of their infertility investigation. In 374 patients with clomiphene-resistant polycystic ovary syndrome (PCOS), ovarian capsule drilling was also performed. The outcome objectives of this study included the evaluation of the added diagnostic value of THL as well as the feasibility and safety of the visual inspection of the female pelvis using this technique. RESULTS: Of the 2288 procedures failed access to the pouch of Douglas occurred in in 23 patients (1%). The complication rate was 0.74%, due to bowel perforations (n= 13) and bleeding (n= 4) requiring laparoscopy. All bowel perforations were treated conservatively, with 6 days of antibiotics, and no further complications occurred. Findings were normal in 49.8% of patients. Endometriosis was diagnosed in 366 patients (15.9%); adhesions were present in 144 patients. CONCLUSIONS: THL is a minimally invasive procedure, with a low complication and failure rate, providing an accurate visual exploration of the female pelvis in a one-day hospital setting. When indicated, minimally invasive surgery is possible in the early stages of endometriosis and for ovarian capsule drilling in patients with clomiphene-resistant PCOS.

Early and late pregnancy loss in women with polycystic ovary syndrome undergoing IVF/ICSI treatment: a retrospective cohort analysis of 21 820 pregnancies.

OBJECTIVE: To examine early and late pregnancy loss in women with and without polycystic ovary syndrome (PCOS) undergoing IVF/ICSI transfers. DESIGN: Retrospective cohort study. SETTING: Reproductive medicine centre at a tertiary hospital. POPULATION: We studied women with a positive ß-human chorionic gonadotropin (ß-hCG) after in vitro fertilisation/intra-cytoplasmic sperm injection (IVF/ICSI) treatment from May 2014 to April 2019. METHODS: Odds ratios (OR) for early (≤13 weeks) and late (>13 weeks) pregnancy loss were calculated among women with and without PCOS for plurality of the pregnancy with adjustment for confounding factors. MAIN OUTCOME MEASURES: Early pregnancy loss (EPL) and late pregnancy loss (LPL). RESULTS: From 21 820 women identified with a positive ß-hCG, 2357 (10.8%) women had PCOS, and 19 463 (89.2%) women did not. EPL occurred in 16.6% (391) of women with PCOS versus 18.3% (3565) in women with non-PCOS (OR 0.89, 95% CI 0.79-0.99, P = 0.04). After adjustment for age and other confounders, the rate of EPL was not statistically significantly associated with PCOS status (adjusted OR [aOR] 0.91, 95% CI 0.80-1.05). Women with PCOS demonstrated a higher rate of LPL (6.4% in PCOS versus 3.6% in non-PCOS, OR 1.81, 95% CI 1.48-2.21, P < 0.001). In multivariable analysis, the potential impact of PCOS was less strong (aOR 1.38, 95% CI 0.96-1.98), with BMI and maternal comorbidities also associated with LPL (aOR 1.08, 95% CI 1.04-1.1 and aOR 2.07, 95% CI 1.43-3.00, respectively). CONCLUSIONS: Polycystic ovary syndrome was not independently associated with EPL. There was an increased risk of LPL but this difference was not statistically significant. TWEETABLE ABSTRACT: Polycystic ovary syndrome women are at increased risk of late pregnancy loss, partly driven by elevated BMI and maternal comorbidities.

A European survey on treatment of hydrosalpinges in infertile women on behalf of the European Society for Gynaecological Endoscopy (ESGE) Special Interest Group (SIG) on Reproductive Surgery.

A questionnaire-based survey was conducted among members of the European Society for Gynaecological Endoscopy (ESGE), with the aim of increasing awareness of the diagnosis and surgical treatment of tubal disease as an alternative to in-vitro fertiliszation (IVF). Seventeen participants (34%) occasionally used a test for prediction of the ovarian reserve before surgery, and the most commonly used test was anti-mullerian hormone assay (39/50; (80%). Laparoscopy was the preferred method for staging tubal disease (43/50; 86%).Thirty-seven (76%) participants always performed salpingectomy or tubal occlusion before the first IVF attempt. Thirty (60%) of the gynaecological surgeons considered the outcome with tubal surgery and IVF to be similar in mild tubal disease, whereas for severe disease, 31/50 (62%) felt that surgery had worse outcome. Among other factors to be considered in choosing a strategy for treating infertility, 20/50 (40%) of respondents listed the stage of disease. The findings of this survey suggest that first-line treatment for women younger than 35 years old with minor tubal pathology, is tubal surgery. IVF appears to be offered if there are other infertility factors, if the patient is >38 years old and if moderate to severe tubal disease is present.

A European survey on the conservative surgical management of endometriotic cysts on behalf of the European Society for Gynaecological Endoscopy (ESGE) Special Interest Group (SIG) on Endometriosis.

The mainstay of endometrioma management, when treatment is required, is surgical. Although laparoscopy is considered to be the gold standard for endometriosis surgery, there is no clarity on the preferred laparoscopic technique, which may depend on whether the primary goalis treatment of infertility or pelvic pain, prevention of recurrence or preservation of ovarian reserve. The aim of this survey to assess the surgical practice of the members of the European Society for Gynaecological Endoscopy (ESGE) on the conservative management of endometiotic cysts in women of reproductive age. The current survey showed that practice for the conservative management of endometriotic cysts was that laparoscopy accounted for 84.9% of the cases, expectant management for 12.1%, and laparotomy for 3%. The preferred surgical approach was cystectomy in 69% of the cases, while the parameters that determined the preferred surgical method were the diameter of the cyst (62%) and the bilaterality or non-location (53%). The type of energy used was in most cases bipolar (83%), 71.4% of surgeons did not reconstitute the ovary and 41% of responses included the administration of adhesion barrier agents. The primary surgical end-point was ovarian reserve (50%), which was tested preoperatively in 51.8%, mainly with an anti-mullerian hormone. In case of an incidentally deep-infiltrating endometriosis, 55.4% of the responses included concomitant treatment thereof, while 71% of the participants considered that a "pelvic surgeon", who could more effectively treat co- existing pelvic and intestinal disease, should be the ideal one to effectively manage endometriosis. The majority of participants (74%) in this survey consider that there is insufficient scientific evidence regarding the conservative management of endometriotic cysts. The treatment of ovarian endometrioma should be individualised, taking into consideration not only the relief of symptoms, pregnancy rates or recurrence rates, but also ovarian function and reserve after surgery.

Modern approaches to surgical management of endometrioma.

Formation of the ovarian endometrioma consists of implantation, invagination of the ovarian cortex, and adhesion formation. Progression is characterized by repeated injury and repair with degenerative changes. Already with a partially deprived ovarian reserve, resulting from the disease, surgical treatment carries a potential risk of further follicular deprivation. Surgery should therefore be performed with microsurgical precision by experienced hands. Early treatment can possibly prevent further progression. The adverse impact on ovarian reserve of the ablative approach has to be balanced against a lower recurrence rate of a cystectomy. Adapted surgical approaches like a two-step approach or a combination of excisional and ablative surgery has to be considered in case of a large endometrioma. Further studies on the possibility and advantages of sclerotherapy are warranted. Fertility preservation by cryopreservation of ovarian cortex should be part of the informed consent with the patient.

Outpatient hysteroscopy.

Modern hysteroscopy represents a copernical revolution for the diagnosis and treatment of uterine pathology. Traditionally hysteroscopy was performed in a conventional operation room under general anaesthesia (in-patient hysteroscopy). Recent advances in technology and techniques made hysteroscopy less painful and invasive allowing it to be performed in an ambulatory setting (outpatient hysteroscopy). The so called "see & treat hysteroscopy", has reduced the distinction between diagnostic and operative procedure, thus, introducing the concept of a single procedure in which the operative part is perfectly integrated within the diagnostic work-up. The "digital hysteroscopic clinic" (DHC) on the other hand combines ultrasound with hysteroscopy, ideal for a one stop diagnostic procedure and surgical approach, outlasting laparoscopy with ultrasound, for increased surgical performance in outpatient settings. The aim of this paper is to describe the "state of the art" in an outpatient hysteroscopy setting.

How do cumulative live birth rates and cumulative multiple live birth rates over complete courses of assisted reproductive technology treatment per woman compare among registries?

STUDY QUESTION: How do the national cumulative (multiple) live birth rates over complete assisted reproduction technology (ART) courses of treatment per woman in Belgium compare to those in other registries? SUMMARY ANSWER: Cumulative live birth rates (CLBRs) remain high with a low cumulative multiple live birth rate when compared with other registries and publications. WHAT IS KNOWN ALREADY: In ART, a reduction in the multiple live birth rate could be achieved by reducing the number of embryos transferred. It has been shown that by doing so, live birth rates per cycle were maintained, particularly when the augmentation effect of attached frozen-thawed cycles was considered. STUDY DESIGN, SIZE, DURATION: A retrospective cohort study included all patients with a Belgian national insurance number who were registered in the national ART registry (Belrap) and who started a first fresh ART cycle between 1 July 2009 until 31 December 2011 with follow up until 31 December 2012. We analysed 12 869 patients and 38 008 cycles (both fresh and attached frozen cycles). PARTICIPANTS, MATERIALS, SETTINGS, METHODS: CLBRs per patient who started a first ART cycle including fresh and consecutive frozen cycles leading to a live birth. Conservative estimates of cumulative live birth assumed that patients who did not return for treatment had no chance of achieving an ART-related live birth, whereas optimal estimates assumed that women discontinuing treatment would have the same chance of achieving a live birth as those continuing treatment. A maximum of six fresh ART cycles with corresponding frozen cycles was investigated and compared with other registries and publications. MAIN RESULTS AND ROLE OF CHANCE: The CLBR was age dependent and declined from 62.9% for women <35 years, to 51.4% for women 35-37 years, to 34.1% for women 38-40 years and 17.7% for women 41-42 years in the conservative analysis after six cycles. In the optimal estimate, the CLBR declined from 85.9% for women <35 years, to 72.0% for women 35-37 years, to 50.4% for women 38-40 years and 36.4% for women 41-42 years. The cumulative multiple live birth rates for the whole population were 5.1 and 8.6% for the conservative and optimal estimate, respectively. LIMITATIONS, REASONS FOR CAUTION: Conservative and optimal estimates use assumptions for the whole ART population and do not take the individual patient into account. WIDER IMPLICATIONS OF THE FINDINGS: These data reinforce the validity of the Belgian model of coupling reimbursement of ART costs to a restriction in the number of embryos transferred. Our data can improve decision-making in medical ART practice both on the patient level and for society at large and could provide health care takers and insurance companies with a valid model. STUDY FUNDING COMPETING INTERESTS: none.

The comprehensiveness of the ESHRE/ESGE classification of female genital tract congenital anomalies: a systematic review of cases not classified by the AFS system.

STUDY QUESTION: How comprehensive is the recently published European Society of Human Reproduction and Embryology (ESHRE)/European Society for Gynaecological Endoscopy (ESGE) classification system of female genital anomalies? SUMMARY ANSWER: The ESHRE/ESGE classification provides a comprehensive description and categorization of almost all of the currently known anomalies that could not be classified properly with the American Fertility Society (AFS) system. WHAT IS KNOWN ALREADY: Until now, the more accepted classification system, namely that of the AFS, is associated with serious limitations in effective categorization of female genital anomalies. Many cases published in the literature could not be properly classified using the AFS system, yet a clear and accurate classification is a prerequisite for treatment. STUDY DESIGN, SIZE AND DURATION: The CONUTA (CONgenital UTerine Anomalies) ESHRE/ESGE group conducted a systematic review of the literature to examine if those types of anomalies that could not be properly classified with the AFS system could be effectively classified with the use of the new ESHRE/ESGE system. An electronic literature search through Medline, Embase and Cochrane library was carried out from January 1988 to January 2014. Three participants independently screened, selected articles of potential interest and finally extracted data from all the included studies. Any disagreement was discussed and resolved after consultation with a fourth reviewer and the results were assessed independently and approved by all members of the CONUTA group. PARTICIPANTS/MATERIALS, SETTING, METHODS: Among the 143 articles assessed in detail, 120 were finally selected reporting 140 cases that could not properly fit into a specific class of the AFS system. Those 140 cases were clustered in 39 different types of anomalies. MAIN RESULTS AND THE ROLE OF CHANCE: The congenital anomaly involved a single organ in 12 (30.8%) out of the 39 types of anomalies, while multiple organs and/or segments of Müllerian ducts (complex anomaly) were involved in 27 (69.2%) types. Uterus was the organ most frequently involved (30/39: 76.9%), followed by cervix (26/39: 66.7%) and vagina (23/39: 59%). In all 39 types, the ESHRE/ESGE classification system provided a comprehensive description of each single or complex anomaly. A precise categorization was reached in 38 out of 39 types studied. Only one case of a bizarre uterine anomaly, with no clear embryological defect, could not be categorized and thus was placed in Class 6 (un-classified) of the ESHRE/ESGE system. LIMITATIONS, REASONS FOR CAUTION: The review of the literature was thorough but we cannot rule out the possibility that other defects exist which will also require testing in the new ESHRE/ESGE system. These anomalies, however, must be rare. WIDER IMPLICATIONS OF THE FINDINGS: The comprehensiveness of the ESHRE/ESGE classification adds objective scientific validity to its use. This may, therefore, promote its further dissemination and acceptance, which will have a positive outcome in clinical care and research. STUDY FUNDING/COMPETING INTERESTS: None.

Terms, definitions and measurements to describe sonographic features of myometrium and uterine masses: a consensus opinion from the Morphological Uterus Sonographic Assessment (MUSA) group.

The MUSA (Morphological Uterus Sonographic Assessment) statement is a consensus statement on terms, definitions and measurements that may be used to describe and report the sonographic features of the myometrium using gray-scale sonography, color/power Doppler and three-dimensional ultrasound imaging. The terms and definitions described may form the basis for prospective studies to predict the risk of different myometrial pathologies, based on their ultrasound appearance, and thus should be relevant for the clinician in daily practice and for clinical research. The sonographic features and use of terminology for describing the two most common myometrial lesions (fibroids and adenomyosis) and uterine smooth muscle tumors are presented.

Hysteroscopic diagnosis and excision of myometrial cystic adenomyosis.

In 1908, Cullen described the first cases of cystic adenomyosis in his textbook on adenomyomata. Although not very common, with the introduction of noninvasive imaging techniques such as magnetic resonance imaging (MRI) and 3-D transvaginal ultrasound, an increasing number of cases have been reported. Patients primarily complain of severe dysmenorrhea, chronic pelvic pain, and dysfunctional uterine bleeding. Currently, it is unclear whether adenomyosis and, more specifically, cystic adenomyosis can be an underlying reason for impaired fertility and reproductive outcome. With the postponement of childbearing, the number of patients with adenomyosis and cystic adenomyosis seeking fertility treatment is increasing. Therefore, in these patients, uterine exploration should include not only the evaluation of the endometrial cavity but also the exploration of the sub-endometrial zone. Indirect imaging techniques, combined with office mini-hysteroscopy, offer the possibility of complete uterine exploration. Two patients with cystic adenomyosis are described in this paper: one had the chief complaint of menorrhagia and the other was referred for evaluation of infertility and severe dysmenorrhea. The aim of these case reports is to present hysteroscopic dissection and ablation of adenomyotic cysts as an alternative procedure for the surgical management of this condition.

Transvaginal endoscopy and small ovarian endometriomas: unravelling the missing link?

The incidence of endometriosis in the infertile female is estimated to be between 20 and 50 %. Although the causal relationship between endometriosis and infertility has not been proven, it is generally accepted that the disease impairs reproductive outcome. Indirect imaging techniques and transvaginal laparoscopy now offer the possibility of an early stage diagnosis. Although it remains debated whether the disease is progressive, treatment in an early stage is recommendable as it carries less risk for ovarian damage, hence premature ovarian failure. Under water, inspection with the technique of transvaginal hydrolaparoscopy (THL) accurately shows the invagination of the ovarian cortex as minimal superficial lesions but with the presence of well-differentiated endometrial like tissue at the base, the lateral walls and especially the inner edges of the small endometrioma. An inflammatory environment is responsible for the formation of connecting adhesions with the broad ligament and lateral wall with invasion of endometrial-like tissue and formation of adenomyotic lesions. In around 50 % of the small endometriomas, adhesiolysis is necessary at the site of invagination with opening of the cyst, to free the chocolate content and hereby recognize the underlying endometrioma. The detailed inspection of these early-stage endometriotic lesions at THL reunites the hypothesis of Sampson with the observation of Hughesdon.

Pleiotropic effects of HDL: towards new therapeutic areas for HDL-targeted interventions.

Plasma levels of high density lipoprotein (HDL) cholesterol levels and of apolipoprotein A-I are inversely correlated with the incidence of coronary heart disease. According to the HDL hypothesis, raising HDL cholesterol is expected to lead to a decrease of coronary heart disease risk. The stringent requirement for proving or refuting this hypothesis is that the causal pathway between the therapeutic intervention and a hard clinical end-point obligatory passes through HDL. The lack of positive clinical results in several recent HDL trials should be interpreted in light of the poor HDL specificity of the drugs that were investigated in these trials. Nevertheless, the results of Mendelian randomization studies further raise the possibility that the epidemiological relationship between HDL cholesterol and coronary artery disease might reflect residual confounding. HDL are circulating multimolecular platforms that exert divergent functions: reverse cholesterol transport, antiinflammatory effects, anti-oxidative effects, immunomodulatory effects, improved endothelial function, increased endothelial progenitor cell number and function, antithrombotic effects, and potentiation of insulin secretion and improvement of insulin sensitivity. Pleiotropic effects of HDL might be translated in clinically significant effects in strategically selected therapeutic areas that are not directly related to native coronary artery disease. In this review, four new therapeutic areas for HDL-targeted diseases are presented: critical illness, allograft vasculopathy and vein graft atherosclerosis, type 2 diabetes mellitus, and heart failure. The strategic selection of these therapeutic areas is not only based on specific functional properties of HDL but also on significant pre-clinical and clinical data that support this choice.

The history of Belgian assisted reproduction technology cycle registration and control: a case study in reducing the incidence of multiple pregnancy.

STUDY QUESTION: What is the effect of a legal limitation of the number of embryos that can be transferred in an assisted reproductive technology (ART) cycle on the multiple delivery rate? SUMMARY ANSWER: The Belgian national register shows that the introduction of reimbursement of ART laboratory costs in July 2003, and the imposition of a legal limitation of the number of embryos transferred in the same year, were associated with a >50% reduction of the multiple pregnancy rate from 27 to 11% between 2003 and the last assessment in 2010, without any reduction of the pregnancy rate per cycle. WHAT IS KNOWN ALREADY: Individual Belgian IVF centres have published their results since the implementation of the law, and these show a decrease in the multiple pregnancy rate on a centre by centre basis. However, the overall national picture remains unpublished. STUDY DESIGN, SIZE, DURATION: Cohort study from 1990 to 2010 of all ART cycles in Belgium (2685 cycles in 1990 evolving to 19 110 cycles in 2010), with a retrospective analysis from 1990 to 2000 and prospective online data collection since 2001. PARTICIPANTS/MATERIALS, SETTING, METHODS: Registration evolved from paper written reports per centre to a compulsory online registration of all ART cycles. From 2001 up to mid-2009, data were collected from Excel spread sheets or MS Access files into an MS Access database. Since mid-2009, data collection is done via a remote and secured web-based system (www.belrap.be) where centres can upload their data and get immediate feedback about missing data, errors and inconsistencies. MAIN RESULTS AND THE ROLE OF CHANCE: National Belgian registration data show that reimbursement of IVF laboratory costs in July 2003, coupled to a legal limitation in the number of embryos transferred in utero, were associated with a 50% reduction of the multiple pregnancy rate from 27 to 11% without reduction of the pregnancy rate per cycle, and with an increase in the number of fresh and frozen ART cycles due to improved access to treatment. LIMITATIONS, REASONS FOR CAUTION: There is potential underreporting of complications of ART treatment, pregnancy outcome and neonatal health. WIDER IMPLICATIONS OF THE FINDINGS: Over the 20 years of registration, the pregnancy rate has remained constant, despite the reduction in the number of embryos transferred, optimization of laboratory procedures and stimulation protocols, introduction of quality systems and implementation of the EU Tissue Directive over the period 2004-2010. STUDY FUNDING/COMPETING INTEREST(S): No external funding was sought for this study. None of the authors has any conflict of interest to declare.