The definition of unexplained infertility: A systematic review.

BACKGROUND: There is no consensus on tests required to either diagnose unexplained infertility or use for research inclusion criteria. This leads to heterogeneity and bias affecting meta-analysis and best practice advice. OBJECTIVES: This systematic review analyses the variability of inclusion criteria applied to couples with unexplained infertility. We propose standardised criteria for use both in future research studies and clinical diagnosis. SEARCH STRATEGY: CINAHL and MEDLINE online databases were searched up to November 2022 for all published studies recruiting couples with unexplained infertility, available in full text in the English language. DATA COLLECTION AND ANALYSIS: Data were collected in an Excel spreadsheet. Results were analysed per category and methodology or reference range. MAIN RESULTS: Of 375 relevant studies, only 258 defined their inclusion criteria. The most commonly applied inclusion criteria were semen analysis, tubal patency and assessment of ovulation in 220 (85%), 232 (90%), 205 (79.5%) respectively. Only 87/220 (39.5%) studies reporting semen analysis used the World Health Organization (WHO) limits. Tubal patency was accepted if bilateral in 145/232 (62.5%) and if unilateral in 24/232 (10.3%). Ovulation was assessed using mid-luteal serum progesterone in 115/205 (56.1%) and by a history of regular cycles in 87/205 (42.4%). Other criteria, including uterine cavity assessment and hormone profile, were applied in less than 50% of included studies. CONCLUSIONS: This review highlights the heterogeneity among studied populations with unexplained infertility. Development and application of internationally accepted criteria will improve the quality of research and future clinical care.

Endogenous progesterone in unexplained infertility: a systematic review and meta-analysis.

PURPOSE: To investigate the possibility that altered actions of endogenous progesterone affect receptivity and contribute to unexplained infertility (UI). METHODS: Two authors electronically searched MEDLINE, CINAHL and Embase databases from inception to 6 July 2022 and hand-searched according to Cochrane methodology. We included all published primary research reporting outcomes related to endogenous progesterone in natural cycles in women with UI. Studies were assessed for risk of bias using a modified Newcastle-Ottawa Score or NHLBI Score. We pooled results where appropriate using a random-effects model. Findings were reported as odds ratios or mean differences. RESULTS: We included 41 studies (n = 4023). No difference was found between the mid-luteal serum progesterone levels of women with UI compared to fertile controls (MD 0.74, - 0.31-1.79, I2 36%). Women with UI had significantly higher rates of 'out-of-phase' endometrium than controls. Nine out of 10 progesterone-mediated markers of endometrial receptivity were significantly reduced in women with UI compared to fertile controls (the remaining 1 had conflicting results). Resistance in pelvic vessels was increased and perfusion of the endometrium and sub-endometrium reduced in UI compared to fertile controls in all included studies. Progesterone receptor expression and progesterone uptake were also reduced in women with unexplained infertility. CONCLUSIONS: End-organ measures of endogenous progesterone activity are reduced in women with UI compared to fertile controls. This apparently receptor-mediated reduction in response affects endometrial receptivity and is implicated as the cause of the infertility. Further research is required to confirm whether intervention could overcome this issue, offering a new option for treating unexplained infertility. TRIAL REGISTRATION: PROSPERO registration: CRD42020141041 06/08/2020.

IUI is a better alternative than IVF as the first-line treatment of unexplained infertility.

The treatment of a condition with no known cause, such as unexplained infertility is, unsurprisingly, controversial. The alternatives that have been suggested for the first-line treatment are expectant management, ovarian stimulation, intrauterine insemination (IUI) with or without ovarian stimulation, or IVF. As far as live births are concerned, the choice has realistically been narrowed down to IUI with ovarian stimulation by low-dose gonadotrophins using strict cancellation criteria versus IVF. In several well-designed studies, three cycles of the former have proved as successful as one cycle of IVF. As IUI is less invasive, more comfortable for the patient, markedly less expensive and safe with a high compliance rate, it should be recommended for the first-line treatment of unexplained infertility for couples in whom the woman's age is not more than 38 years.

SARS-CoV-2: diagnostic and design conundrums in the context of male factor infertility.

The question of whether SARS-CoV-2 (severe acute respiratory syndrome-related coronavirus-2 [SARS-CoV-2], leading to the COVID-19 infection) can be harboured in the testes and/or semen is currently unanswered. It is essential to understand the limitations of both antibody and real-time PCR tests in interpreting SARS-CoV-2 data in relation to analyses of semen and testicular tissue without appropriate controls. This article critically analyses the evidence so far on this, and the possible implications. The limitations of diagnostic tests in both sampling and testing methodologies, their validation and their relevance in interpreting data are also highlighted.

The regulation and signalling of anti-Müllerian hormone in human granulosa cells: relevance to polycystic ovary syndrome.

STUDY QUESTION: What prevents the fall in anti-Müllerian hormone (AMH) levels in polycystic ovary syndrome (PCOS) and what are the consequences of this for follicle progression in these ovaries? SUMMARY ANSWER: Exposure of granulosa cells (GCs) to high levels of androgens, equivalent to that found in PCOS, prevented the fall in AMH and was associated with dysregulated AMH-SMAD signalling leading to stalled follicle progression in PCOS. WHAT IS KNOWN ALREADY: In normal ovaries, AMH exerts an inhibitory role on antral follicle development and a fall in AMH levels is a prerequisite for ovulation. Levels of AMH are high in PCOS, contributing to the dysregulated follicle growth that is a common cause of anovulatory infertility in these women. STUDY DESIGN, SIZE, DURATION: Human KGN-GC (the cell line that corresponds to immature GC from smaller antral follicles (AF)) were cultured with a range of doses of various androgens to determine the effects on AMH production. KGN-GC were also treated with PHTPP (an oestrogen receptor ß (ERß) antagonist) to examine the relationship between AMH expression and the ratio of ERα:ERß. The differential dose-related effect of AMH on gene expression and SMAD signalling was investigated in human granulosa-luteal cells (hGLC) from women with normal ovaries, with polycystic ovarian morphology (PCOM) and with PCOS. KGN-GC were also cultured for a prolonged period with AMH at different doses to assess the effect on cell proliferation and viability. PARTICIPANTS/MATERIALS, SETTING, METHODS: AMH protein production by cells exposed to androgens was measured by ELISA. The effect of PHTPP on the mRNA expression levels of AMH, ERα and ERß was assessed by real-time quantitative PCR (qPCR). The influence of AMH on the relative mRNA expression levels of aromatase, AMH and its receptor AMHRII, and the FSH and LH receptor (FSHR and LHR) in control, PCOM and PCOS hGLCs was quantified by qPCR. Western blotting was used to assess changes in levels of SMAD proteins (pSMAD-1/5/8; SMAD-4; SMAD-6 and SMAD-7) after exposure of hGLCs from healthy women and women with PCOS to AMH. The ApoTox-Glo Triplex assay was used to evaluate the effect of AMH on cell viability, cytotoxicity and apoptosis. MAIN RESULTS AND THE ROLE OF CHANCE: Testosterone reduced AMH protein secreted from KGN-GC at 10-9-10-7 M (P < 0.05; P < 0.005, multiple uncorrected comparisons Fishers least squares difference), but at equivalent hyperandrogenemic levels no change was seen in AMH levels. 5α-DHT produced a significant dose-related increase in AMH protein secreted into the media (P = 0.022, ANOVA). Increasing the mRNA ratio of ERα:ERß produced a corresponding increase in AMH mRNA expression (P = 0.015, two-way ANOVA). AMH increased mRNA levels of aromatase (P < 0.05, one-way ANOVA) and FSHR (P < 0.0001, one-way ANOVA) in hGLCs from women with PCOM, but not from normal cells or PCOS (normal n = 7, PCOM n = 5, PCOS n = 4). In contrast to hGLCs from ovulatory ovaries, in PCOS AMH reduced protein levels (cell content) of stimulatory pSMAD-1/5/8 and SMAD-4 but increased inhibitory SMAD-6 and -7 (P < 0.05, normal n = 6, PCOS n = 3). AMH at 20 and 50 ng/ml decreased KGN-GC cell proliferation but not viability after 8 days of treatment (P < 0.005, two-way ANOVA). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Luteinised GC from women undergoing IVF have a relatively low expression of AMH/AMHRII but advantageously continue to display responses inherent to the ovarian morphology from which they are collected. To compensate, we also utilised the KGN cell line which has been characterised to be at a developmental stage close to that of immature GC. The lack of flutamide influence on testosterone effects is not in itself sufficient evidence to conclude that the effect on AMH is mediated via conversion to oestrogen, and the effect of aromatase inhibitors or oestrogen-specific inhibitors should be tested. The effect of flutamide was tested on testosterone but not DHT. WIDER IMPLICATIONS OF THE FINDINGS: Normal folliculogenesis and ovulation are dependent on the timely reduction in AMH production from GC at the time of follicle selection. Our findings reveal for the first time that theca-derived androgens may play a role in this model but that this inhibitory action is lost at levels of androgens equivalent to those seen in PCOS. The AMH decline may either be a direct effect of androgens or an indirect one via conversion to oestradiol and acting through the upregulation of ERα, which is known to stimulate the AMH promoter. Interestingly, the ability of GCs to respond to this continually elevated AMH level appears to be reduced in cells from women with PCOS due to an adaptive alteration in the SMAD signalling pathway and lower expression of AMHRII, indicating a form of 'AMH resistance'. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Thomas Addison Scholarship, St Georges Hospital Trust. The authors report no conflict of interest in this work and have nothing to disclose. TRIAL REGISTRATION NUMBER: N/A.

Biomarkers of ovarian reserve in childhood and adolescence: A systematic review.

INTRODUCTION: Certain medical disorders as well as their management may affect gonadal function. Recent advances in the management of these conditions accompanied by the availability and success of methods of fertility preservation has highlighted the need for assessment of ovarian reserve in childhood and adolescence. Serum anti-Mullerian hormone (AMH) and antral follicle count are well established markers of ovarian reserve and serum inhibin has also been used. However, literature on reference ranges for ovarian reserve markers in this age-group is relatively scarce. Thus, our aim was to evaluate published data to estimate reference values of ovarian reserve makers in childhood and adolescence. MATERIAL AND METHODS: We performed a systematic review of the literature reporting ovarian reserve markers in childhood and adolescence. We included only those studies examining markers of ovarian reserve in the normal healthy population between the ages of 0 and 19 years. PROSPERO registration: CRD42018119064. RESULTS: Serum AMH emerged as the most common biomarker assessed. Serum AMH was detectable at birth and, after a transient increase in infancy, increased steadily in childhood. Following a slight decrease at puberty, levels were constant throughout adolescence with a peak in adolescence or early adulthood. The mean serum AMH values during infancy, childhood and adolescence were 10.55, 22.32 and 31.84 pmol/L, respectively. The corresponding median values were 9.85, 24.49 and 26.32 pmol/L. It was not possible to construct age-specific reference intervals because of methodological heterogeneity, variations in the assay used to measure AMH and differing interval width for age used in included studies. Serum inhibin showed an increase from childhood to adolescence, with median serum inhibin values of 53.86 pg/mL in adolescence. Antral follicle count showed a significant positive correlation with serum AMH and a median value of 30.52 in adolescence. CONCLUSIONS: We summarize the trends and levels of biomarkers of ovarian reserve from birth until young adulthood. Peak levels of serum AMH are reported in adolescence or early adulthood. We have reported median/mean values for serum AMH in different age-groups based on data pooled from several studies, which may be used as a reference when evaluating ovarian reserve in childhood and adolescence especially when considering fertility preservation.

The effect of myo-inositol/di-chiro-inositol on markers of ovarian reserve in women with PCOS undergoing IVF/ICSI: A systematic review and meta-analysis.

INTRODUCTION: High levels of anti-Mullerian hormone and a high antral follicle count in women with polycystic ovary syndrome, reflecting increased ovarian antral follicles, predisposes them to have a high number of retrieved oocytes with in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) and an increased risk of ovarian hyperstimulation syndrome. Inositols, which act as insulin sensitizers, have the potential to alter folliculogenesis and the functional ovarian reserve, with subsequent benefits to reproductive outcomes following IVF/ICSI treatment. Published literature is, however, unable to provide definitive evidence of its efficacy. The objective of our review was to evaluate the effect of inositols on anti-Mullerian hormone, antral follicle count and reproductive outcomes in women with polycystic ovary syndrome undergoing IVF/ICSI. MATERIAL AND METHODS: We performed a literature search using standard methodology recommended by Cochrane. Randomized controlled trials and non-randomized studies comparing inositols with no treatment, placebo or other treatment were included in the review. Using standard methodology recommended by Cochrane we pooled results using the random effects model; our findings were reported as relative risk or mean differences. PROSPERO registration: CRD42017082275. RESULTS: We included 18 trials. The primary outcome was a change in anti-Mullerian hormone and antral follicle count before and after treatment, for which data were unsuitable for meta-analysis. A narrative review showed no consistent direction or size of effect. A meta-analysis for the secondary outcomes showed no evidence of a significant difference between inositol and control groups for any outcome: number of oocytes (mean difference -0.39, 95% confidence interval [CI] -1.11 to 0.33), number of metaphase II oocytes (mean difference 0.29, 95% CI -0.83 to 1.40), number of top grade embryos (risk ratio [RR] 1.02, 95% CI 0.93-1.12), clinical pregnancy rate (RR 1.16, 95% CI 0.87-1.53), and risk of ovarian hyperstimulation syndrome (RR 0.73, 95% CI 0.39-1.37). The quality of evidence was assessed as very low. CONCLUSIONS: There is insufficient evidence for an effect of inositols on ovarian reserve markers and to support their use as pretreatment before IVF/ICSI in women with polycystic ovary syndrome.

A novel method to demonstrate that pregnant women with polycystic ovary syndrome hyper-expose their fetus to androgens as a possible stepping stone for the developmental theory of PCOS. A pilot study.

BACKGROUND: Polycystic ovary syndrome (PCOS), whose aetiology is unknown, is predominately a familial syndrome but confirmation of candidate genes has proved elusive. The developmental hypothesis for the origin of PCOS suggests that exposure of the fetus to excess androgens influences imprinting, leading to altered genetic expression in adult life. The aim of this pilot study was to examine whether the female fetus of a mother with PCOS is indeed exposed to excess androgens. METHODS: Using sebum production in the newborn as a surrogate for exposure to excess androgens during pregnancy thisprospective case control studyexamined whether neonatal sebum excretion is greater in female infants born to PCOS mothers compared to non-PCOS. Women with known PCOS (all 3 Rotterdam criteria) (n = 9) and non-PCOS controls (n = 12), with a female fetus, were recruited at 24 weeks pregnancy and serum testosterone estimated. Sebum was measured using Sebutape® for 30 and 60 min within 24 h of birth, at 1 week, 4-6 weeks and 6 months after birth in both mother and child. Sebum excretion was measured in mother and child in the same site at each time frame and consistently. All semi-quantitative sebum excretion estimations were compared (t-test) between the two groups and correlated with testosterone concentrations during pregnancy. RESULTS: In this pilot study, 21 women completed the 6 month examination period (PCOS group (n = 9) and controls (n = 12). Mean testosterone was 6.2 nmol/L (normal <3.1 nmol/L) in PCOS mothers and 2.75 nmol/L in controls at 24 weeks pregnancy. At all time frames, the results of sebum excretion at 30 and 60 min were consistent. The sebum excretion of mothers in both groups was fairly constant from birth throughout 6 months. All babies were born between 37 and 41 weeks gestational age. Six of nine newborns had detectable sebum excretion at birth in the PCOS mothers group compared to 1 of 12 in the controls (P = 0.01). CONCLUSIONS: These results suggest that women with PCOS could hyper-expose their fetus to androgens in-utero and that this may be detected using a simple novel test within 24 h of birth to predict development of PCOS in adult life and induce research to eliminate its symptoms. TRIAL REGISTRATION: NCT 02654548 .Clinical Trials UK.Retrospectively registered 11/1/16.

Preliminary investigation of the prevalence and implantation potential of abnormal embryonic phenotypes assessed using time-lapse imaging.

This retrospective, single site observational study aimed to delineate five abnormal embryonic developmental phenotypes, assessing their prevalence, development potential and suitability for inclusion in embryo selection models for IVF. In total, 15,819 embryos from 4559 treatment cycles cultured in EmbryoScope® incubators between January 2014 and January 2016 were included. Time-lapse images were assessed retrospectively for five abnormal embryo phenotypes: direct cleavage, reverse cleavage, absent cleavage, chaotic cleavage and cell lysis. The prevalence of each abnormal phenotype was assessed. Final embryo disposition, embryo quality and implantation rate were determined and compared with a control embryo cohort. The collective prevalence for the five abnormal phenotypes was 11.4%; chaotic cleavage and direct cleavage together constituted 9.7%. Implantation rates were 17.4%, 0%, 25%, 2.1% and 0% for direct, reverse, absent, chaotic cleavage and cell lysis, respectively. The overall implantation rate for all abnormal embryos with known implantation status was significantly lower compared with the control population (6.9% versus 38.7%, P < 0.0001). The proportion of good quality embryos in each category of abnormal cleavage remained below 25%. Embryos exhibiting an abnormal phenotype may have reduced developmental capability, manifested in both embryo quality and implantation potential, when compared with embryos of normal phenotype.

Phenotypic variation in anti-Mullerian hormone (AMH) production per follicle in women with polycystic ovary syndrome (PCOS) and isolated polycystic ovarian morphology (PCOM): an observational cross-sectional study.

This observational study compares the ratio of serum anti-Mullerian hormone (AMH) to the total antral follicle count (AFC) (as a marker of AMH production per follicle) in the various phenotypes of women with polycystic ovary syndrome (PCOS) and isolated polycystic ovarian morphology (PCOM). Two hundred and sixty-two women were recruited. Women with PCOS were divided into four phenotypes based on the diagnostic inclusion criteria of oligo-anovulation (OA), hyperandrogenism (HA) and polycystic ovarian morphology (PCOM). These included Group A (OA + HA + PCOM), Group B (OA + HA), Group C (HA + PCOM) and Group D (OA + PCOM). A ratio of serum AMH to total AFC was calculated and expressed as the AMH/AFC ratio which was compared in the phenotypes of PCOS and isolated PCOM. The median AMH/AFC ratios in PCOS-A, PCOS-D, PCOS-C and PCOM were 1.5, 1.6, 1.2 and 1.1, respectively. There were significant differences in the groups compared [F(3, 238) = 6.14, p = 0.000)]. The ratios were significantly higher in the oligo-anovulatory phenotypes PCOS-A and PCOS-D than the PCOM (p = 0.004 and 0.002, respectively). There was no significant difference in the ratio between ovulatory phenotype PCOS-C and PCOM (p = 0.59). The role of androgens and LH in per-follicle AMH production remains limited. The findings support the hypothesis of a key role for AMH in the mechanism of anovulation in PCOS.

Risk of adverse pregnancy and perinatal outcomes after high technology infertility treatment: a comprehensive systematic review.

In the literature, there is growing evidence that subfertile patients who conceived after infertility treatments have an increased risk of pregnancy and perinatal complications and this is particularly true for patients who conceived through use of high technology infertility treatments. Moreover, high technology infertility treatments include many concomitant clinical and biological risk factors. This review aims to summarize in a systematic fashion the current evidence regarding the relative effect of the different procedures for high technology infertility treatments on the risk of adverse pregnancy and perinatal outcome. A literature search up to August 2016 was performed in IBSS, SocINDEX, Institute for Scientific Information, PubMed, Web of Science and Google Scholar and an evidence-based hierarchy was used to determine which articles to include and analyze. Data on prepregnancy maternal factors, low technology interventions, specific procedures for male factor, ovarian tissue/ovary and uterus transplantation, and chromosomal abnormalities and malformations of the offspring were excluded. The available evidences were analyzed assessing the level and the quality of evidence according to the Oxford Centre for Evidence-Based Medicine guidelines and the Grading of Recommendations Assessment, Development, and Evaluation system, respectively. Current review highlights that every single procedure of high technology infertility treatments can play a crucial role in increasing the risk of pregnancy and perinatal complications. Due to the suboptimal level and quality of the current evidence, further well-designed studies are needed.

The role of AMH in anovulation associated with PCOS: a hypothesis.

Polycystic ovary syndrome (PCOS) is the most common cause of infertility due to anovulation. Despite its prevalence, the precise cause of the anovulation is yet to be clearly defined. There is an increased number of pre-antral and antral follicles in the polycystic ovary, many of which individually produce increased amounts of anti-Müllerian hormone (AMH) compared with those in the normal ovary. In this article, it is hypothesized that the high AMH concentrations present in women with PCOS play an integral role in causing anovulation due to its inhibitory influence on the actions of follicle-stimulating hormone, which normally promotes follicular development from the small antral to the ovulatory stage.

Anti-Müllerian hormone as a predictor of pregnancy following IVF.

This single-centre retrospective observational study was performed at a university IVF centre. The aim was to examine the predictive power of AMH concentrations for clinical pregnancy rate (CPR) and establish a cut-off concentration of AMH below which no pregnancies were achieved. Data from 820 women with one treatment cycle each were analysed. There was a significant difference in CPR (24.4% and 40.0%; P<0.01) between the lowest and highest quartiles of AMH. This study failed to establish a cut-off concentration of AMH below which there were no clinical pregnancies as several pregnancies were achieved despite an AMH less than 1pmol/l. Log AMH showed a strong positive correlation with number of oocytes retrieved (r=0.522; P<0.001). Log AMH and overall CPR were weakly correlated (r=0.112, P<0.001), but this was not maintained when controlled for the number of oocytes. Age was a stronger independent predictor of CPR than AMH. In conclusion, although an excellent marker of ovarian response, AMH is only a weak predictor of clinical pregnancy. With AMH below the third percentile, CPR was 15%. However AMH is very useful for patient counselling and assessment when used in conjunction with age.

Pregnancy prognosis in women with anti-Müllerian hormone below the tenth percentile.

Although serum anti-Müllerian hormone (AMH) is considered a good predictor of ovarian response during in vitro fertilisation (IVF), pregnancies have been reported with low values, questioning its usefulness as a predictor of treatment outcome. A retrospective study was therefore carried out to assess the IVF treatment outcomes in women with AMH below the tenth percentile of the study population. In all, 134 women with AMH ≤ 3 pmol/L underwent 180 IVF cycles. The mean age at the time of treatment was 37 ± 5 years. Fifty-three (29.4%) cycles were abandoned because of poor response to gonadotrophins, 12 (6.7%) due to absence of eggs at oocyte retrieval and 18 (10%) due to fertilisation failure. Seven (3.8%) had a biochemical pregnancy, 4 (2.2%) had a missed miscarriage and 8 (4.4%) had a live birth. When stratified by age, women older than 42 years had less number of follicles (p < 0.05) and those older than 39 years had less oocytes (p < 0.01) compared to those 35 years and younger. Live births declined with increasing age, when age was assessed as a continuous variable (p = 0.023). Women with low AMH levels have a high probability of treatment cancellation, failure to proceed to embryo transfer and a low chance of achieving a viable pregnancy.

[In-vitro fertilization cycles and outcomes in Maccabi Healthcare Services in Israel 2007-2010].

INTRODUCTION: While Israel is by far number one in the world of in-vitro fertilization (IVF) treatments per capita, detailed information about the outcome of these treatments is not available. OBJECTIVES: To describe IVF activity during the years 2007-2010 in Maccabi Healthcare Services, an independent health provider that reimburses IVF treatments. METHODS: Data on IVF cycles and live births were collected from the Maccabi Healthcare Services infertility registry and analyzed by year and age at cycle start. RESULTS: During the four years surveyed, the average patients' age rose from 35.12 to 36.19 years. The number of IVF treatments increased by 50%, while the "live birth" rate fell from 18.8% in 2007, to 14.8% in 2010. A drop in success rate was noted in patients >35 years of age, and more so in patients >40 years of age. Beyond 43 years of age, the success rate was in the low one digit range. The estimated cost of a single live birth in this age group is NIS 399,000. SUMMARY: The clinical results are not encouraging relative to IVF outcomes in Europe and the U.S.A. SurprisingLy, and contrary to worldwide trends, the success rate in Israel decreased during the surveyed years. We speculate that the main reason is that many IVF treatments are conducted in patients that a priori have a very low chance of success. A nationwide prospective IVF registry should be implemented.

Should women with high body mass index be denied fertility treatments?

Obesity is an emerging global epidemic with a negative impact on fertility. Almost all guidelines and policies have a stringent limit of body mass index (BMI) to access fertility services which has promoted a debate amongst fertility practitioners globally. Proponents of placing such a limit point to the negative impact of elevated BMI on the outcome of fertility treatment, its cost effectiveness and the risk it poses to the intending mother and unborn child. Opponents of placing a restriction base their arguments on the lack of conclusive, robust evidence regarding the variables along with the ethical dilemmas of promoting discrimination and stigmatization by denying a couple their basic right of parenthood. In this review, we analyse these medical and ethical dilemmas in the light of current evidence. The focus is on female infertility.

Implantation in the lower half of the uterine cavity and decreased trophoblastic thickness can predict subsequent miscarriage: a prospective cohort study.

Abstract: Embryo implantation is vital for successful conception but remains to be fully understood. Trophoblast invasion is key for implantation, with anchorage and depth of placentation determined by its extent. There is a dearth of synchronous information regarding IVF, implantation site, and trophoblastic thickness (TT). Our aim was to determine whether pregnancy implantation site and TT, had an impact on outcomes of IVF pregnancies. This prospective observational study was undertaken at a tertiary referral UK fertility unit over 14 months, collecting data on implantation site and TT from three-dimensional (3D) images of the uterus following early pregnancy scan. Of the 300 women recruited, 277 (92%) had live births, 20 (7%) miscarried, 2 (0.7%) had stillbirths, and 1 (0.3%) had a termination. Significantly more pregnancies that resulted in miscarriage (7/20, 35%) were located in the lower uterine cavity when compared to ongoing pregnancies (15/277, 5%) (P < 0.01). TT was significantly higher in ongoing pregnancies when compared with those who miscarried (7.2 mm vs 5.5 mm; P < 0.01). Implantation in the lower half of the uterine cavity and decreased TT are significantly associated with an increased rate of miscarriage. Identification of those at risk should prompt increased monitoring with the aim of supporting these pregnancies. Lay summary: Implantation of an embryo in the womb is vital for a successful pregnancy. We wanted to find out whether findings on an ultrasound scan in early pregnancy had an impact on outcomes of IVF pregnancies. Three hundred women were recruited to the study, 277 (92%) had live births and unfortunately 20 (7%) had a miscarriage, 2 (0.7%) had stillbirths, and 1 (0.3%) had a termination. Many more of the pregnancies that miscarried implanted in the lower part of the womb. The thickness of the infiltration of the pregnancy into the womb was significantly higher in the ongoing pregnancies. We concluded that implantation in the lower half of the womb and reduced infiltration of the pregnancy seen on scan are associated with an increased rate of miscarriage. We propose that when we identify those at risk, we should increase monitoring, with the aim of supporting these pregnancies.

Correlation of IVF outcomes and number of oocytes retrieved: a UK retrospective longitudinal observational study of 172 341 non-donor cycles.

OBJECTIVE: How do numbers of oocytes retrieved per In vitro fertilisation (IVF) cycle impact on the live birth rate (LBR) and multiple gestation pregnancy (MGP) rates? DESIGN: Retrospective observational longitudinal study. SETTING: UK IVF clinics. POPULATION: Non-donor IVF patients. MAIN OUTCOME MEASURES: LBR per IVF cycle and MGP levels against number of oocytes retrieved into subgroups: 0, 1-5, 6-15, 16-25, 26-49 oocytes and 50+ oocytes. Relative risk (RR) and 95% CIs were calculated for each group against the intermediate responder with '6-15 oocytes collected'. RESULTS: From 172 341 attempted fresh oocyte retrieval cycles, the oocyte retrieved was: 0 in 10 148 (5.9%) cycles from 9439 patients; 1-5 oocytes in 42 574 cycles (24.7%); 6-15 oocytes in 91 797 cycles (53.3%); 16-25 oocytes in 23 794 cycles (13.8%); 26-49 oocytes in 3970 cycles (2.3%); ≥50 oocytes in 58 cycles (0.033%). The LBRs for the 1-5, 6-15, 16-25 and 26-49 subgroups of oocytes retrieved were 17.2%, 32.4%, 35.3% and 18.7%, respectively. The RR (95% CI) of live birth in comparison to the intermediate group (6-15) for 1-5, 16-25 and 26-49 groups was 0.53 (0.52 to 0.54), 1.09 (1.07 to 1.11) and 0.58 (0.54 to 0.62), respectively. The corresponding MGP rates and RR were 9.2%, 11.0%, 11.4% and 11.3%, respectively and 0.83 (0.77 to 0.90), 1.04 (0.97 to 1.11) and 1.03 (0.84 to 1.26), respectively. CONCLUSION: There was only limited benefit in LBR beyond the 6-15 oocyte group going to the 16-25 oocytes group, after which there was significant decline in LBR. The MGP risk was lower in 1-5 group.