Fertility treatment pathways and births for women with and without polycystic ovary syndrome-a retrospective population linked data study.

OBJECTIVE: To study the fertility treatment pathways used by women with and without polycystic ovary syndrome (PCOS) and which pathways were more likely to result in a birth. DESIGN: This retrospective national community-based cohort study used longitudinal self-report survey data (collected 1996-2022; aged 18-49 years) from women born in 1973-1978 who are participants in the Australian Longitudinal Study on Women's Health. The study also used linked administrative data on fertility treatments (1996-2021). PATIENTS: Of the 8,463 eligible women, 1,109 accessed fertility treatment and were included. EXPOSURE: Polycystic ovary syndrome diagnosis was self-reported. MAIN OUTCOME MEASURE: use of ovulation induction (OI), intrauterine insemination, and/or in vitro fertilization (IVF) was established through linked administrative data. Births were self-reported. RESULTS: One in 10 of the eligible participants had PCOS (783/7,987, 10%) and 1 in 4 of the women who used fertility treatment had PCOS (274/1,109, 25%). Women with PCOS were 3 years younger on average at first fertility treatment (M = 31.4 years, SD = 4.18) than women without PCOS (M = 34.2 years, SD = 4.56). Seven treatment pathways were identified and use differed by PCOS status. Women with PCOS were more likely to start with OI (71%; odds ratio [OR] 4.20, 95% confidence interval [CI]: 2.91, 6.07) than women without PCOS (36%). Of the women with PCOS who started with OI, 46% required additional types of treatment. More women without PCOS ended up in IVF (72% vs. 51%). Overall, 63% (701/1,109) had an attributed birth, and in adjusted regressions births did not vary by last type of treatment (IVF: 67%, reference; intrauterine insemination: 67%, OR 0.94 95% CI: 0.56, 1.58; OI: 61%, OR 0.71, 95% CI: 0.52, 0.98), or by PCOS status (OR 1.27, 95% CI: 0.91, 1.77). By age, 74% of women under 35 years (471/639) and 49% of women 35 years or older had a birth. CONCLUSION: More women with PCOS used fertility treatment but births were equivalent to women without PCOS. Most women followed clinical recommendations. Births did not differ between pathways, so there was no disadvantage in starting with less invasive treatments (although there may be financial or emotional disadvantages).

Nampt-mediated spindle sizing secures a post-anaphase increase in spindle speed required for extreme asymmetry.

Meiotic divisions in oocytes are extremely asymmetric and require pre- and post-anaphase-onset phases of spindle migration. The latter induces membrane protrusion that is moulded around the spindle thereby reducing cytoplasmic loss. Here, we find that depleting the NAD biosynthetic enzyme, nicotinamide phosphoribosyl-transferase (Nampt), in mouse oocytes results in markedly longer spindles and compromises asymmetry. By analysing spindle speed in live oocytes, we identify a striking and transient acceleration after anaphase-onset that is severely blunted following Nampt-depletion. Slow-moving midzones of elongated spindles induce cortical furrowing deep within the oocyte before protrusions can form, altogether resulting in larger oocyte fragments being cleaved off. Additionally, we find that Nampt-depletion lowers NAD and ATP levels and that reducing NAD using small molecule Nampt inhibitors also compromises asymmetry. These data show that rapid midzone displacement is critical for extreme asymmetry by delaying furrowing to enable protrusions to form and link metabolic status to asymmetric division.

A Review of Second- and Third-line Infertility Treatments and Supporting Evidence in Women with Polycystic Ovary Syndrome.

In clomiphene-citrate-resistant anovulatory women with polycystic ovary syndrome (PCOS) and no other infertility factors, either metformin combined with clomiphene citrate or gonadotrophins could be used as a second-line pharmacological therapy, although gonadotrophins are more effective. Gonadotrophins could also be used as a second-line pharmacological therapy in anovulatory women with PCOS and clomiphene-citrate-failure. Laparoscopic ovarian surgery can also be used as a second-line therapy for ovulation induction in anovulatory women with clomiphene-citrate-resistant PCOS and no other infertility factors. The usefulness of letrozole as a second-line pharmacological treatment for ovulation induction in clomiphene-citrate-resistant women with PCOS requires further research. In terms of improving fertility, both pharmacological anti-obesity agents and bariatric surgery should be considered an experimental therapy in anovulatory women with PCOS and no other infertility factors. Where first- or second-line ovulation induction therapies have failed, in vitro fertilization (IVF)/ intracytoplasmic sperm injection (ICSI) could be offered as a third-line therapy in women with PCOS in the absence of an absolute indication for IVF/ICSI. For women with PCOS undergoing IVF/ICSI treatment, the gonadotropin-releasing hormone (GnRH) antagonist protocol is preferred and an elective frozen embryo transfer strategy could be considered. In assisted conception units with sufficient expertise, in-vitro maturation (IVM) of oocytes could be offered to women with PCOS.

Preimplantation genetic testing for aneuploidy (PGT-A): The biology, the technology and the clinical outcomes.

Preimplantation genetic testing for aneuploidy (PGT-A) seeks to identify preimplantation embryos with a normal chromosome complement (euploid) during in vitro fertilisation (IVF). By sifting out embryos with abnormal chromosome numbers (aneuploid), PGT-A should theoretically improve pregnancy success. However, earlier versions of PGT-A were ineffective, and in some cases, detrimental, due to biopsy-induced trauma and because the technology at the time could analyse only a fraction of all chromosomes. More recently, the emergence of technologies enabling all chromosomes to be analysed and a switch to less traumatic blastocyst-stage biopsy have seen widespread uptake of PGT-A. Assessing the full impact of blastocyst biopsy PGT-A requires consideration of multiple factors, including embryonic mosaicism, sensitivity of the technological platform used, embryo loss during long-term in vitro culture, embryo cryopreservation and inter-clinic variability in expertise. Significantly, there hasnt yet been an appropriately designed randomised controlled trial (RCT) of blastocyst biopsy PGT-A analysed by intention-to-treat that accounts for all these parameters on a per-cycle basis. The three RCTs reporting benefits studied outcomes on a per-embryo transfer basis were small and underpowered and demonstrated benefits for a very select sub-group of good prognosis patients. The liberal use of this very expensive IVF add-on for other patient populations has not yet been shown to be effective, or indeed, without harm.

Review: Embryo- and endometrium-derived exosomes and their potential role in assisted reproductive treatments-liquid biopsies for endometrial receptivity.

Multiple pregnancies resulting from the transfer of more than one embryo pose a significant threat to offspring born through Assisted Reproductive Treatments (ART). Transferring one embryo at a time would eliminate this risk. However, current approaches of identifying the highest quality embryo to transfer are either unreliable (e.g. morphology assessment) or highly invasive and potentially detrimental to embryos (e.g. PGD). Approaches for non-invasive embryo selection would be a major advancement that would increase efficiency and reduce both the costs and the risks associated with ART. Exosomes are a particular subtype of extracellular vesicles (EVs) that are secreted from a wide range of cells, including placental and endometrium cells. Exosomes are very stable vesicles that contain a broad spectrum of molecules, including proteins, mRNAs and miRNAs. Very little is known about this form of cell-to-cell communication in the context of ovarian follicular biology and implantation, but emerging data suggest that exosomes secreted by the blastocyst could influence gene expression and receptivity of endometrial cells thereby controlling its own implantation. Here we review emerging findings regarding exosomal signalling in reproductive biology and the prospects for mapping blastocyst-derived exosomal profiles as a means for supporting single embryo transfer policies.

Hec1-dependent cyclin B2 stabilization regulates the G2-M transition and early prometaphase in mouse oocytes.

The functions of the Ndc80/Hec1 subunit of the highly conserved Ndc80 kinetochore complex are normally restricted to M phase when it exerts a pivotal kinetochore-based role. Here, we find that in mouse oocytes, depletion of Hec1 severely compromises the G2-M transition because of impaired activation of cyclin-dependent kinase 1 (Cdk1). Unexpectedly, impaired M phase entry is due to instability of the Cdk1-activating subunit, cyclin B2, which cannot be covered by cyclin B1. Hec1 protects cyclin B2 from destruction by the Cdh1-activated anaphase-promoting complex (APC(Cdh1)) and remains important for cyclin B2 stabilization during early M phase, required for the initial stages of acentrosomal spindle assembly. By late M phase, however, Hec1 and cyclin B2 become uncoupled, and although Hec1 remains stable, APC(Cdc20) triggers cyclin B2 destruction. These data identify another dimension to Hec1 function centered on M phase entry and early prometaphase progression and challenge the view that cyclin B2 is completely dispensable in mammals.

Spindle assembly checkpoint signalling is uncoupled from chromosomal position in mouse oocytes.

The spindle assembly checkpoint (SAC) averts aneuploidy by coordinating proper bipolar chromosomal attachment with anaphase-promoting complex/cyclosome (APC/C)-mediated securin and cyclin B1 destruction required for anaphase onset. The generation of a Mad2-based signal at kinetochores is central to current models of SAC-based APC/C inhibition. During mitosis, kinetochores of polar-displaced chromosomes, which are at greatest risk of mis-segregating, recruit the highest levels of Mad2, thereby ensuring that SAC activation is proportionate to aneuploidy risk. Paradoxically, although an SAC operates in mammalian oocytes, meiosis I (MI) is notoriously error prone and polar-displaced chromosomes do not prevent anaphase onset. Here we find that Mad2 is not preferentially recruited to the kinetochores of polar chromosomes of wild-type mouse oocytes, in which polar chromosomes are rare, or of oocytes depleted of the kinesin-7 motor CENP-E, in which polar chromosomes are more abundant. Furthermore, in CENP-E-depleted oocytes, although polar chromosomal displacement intensified during MI and the capacity to form stable end-on attachments was severely compromised, all kinetochores nevertheless became devoid of Mad2. Thus, it is possible that the ability of the SAC to robustly discriminate chromosomal position might be compromised by the propensity of oocyte kinetochores to become saturated with unproductive attachments, thereby predisposing to aneuploidy. Our data also reveal novel functions for CENP-E in oocytes: first, CENP-E stabilises BubR1, thereby impacting MI progression; and second, CENP-E mediates bi-orientation by promoting kinetochore reorientation and preventing chromosomal drift towards the poles.

Complications associated with uterine artery embolisation for fibroids.

Uterine artery embolisation (UAE) is a relative newcomer to the mainstream treatment modalities available for fibroid-related problems. The efficacy of UAE is indisputable and has been shown to be comparable to hysterectomy in the short term in large-scale trials. Moreover, compared with hysterectomy, UAE is less invasive, carries a superior risk profile, and, importantly, preserves the uterus. UAE therefore offers patients symptom relief whilst at the same time retaining reproductive potential. Notably however, although women can have successful pregnancies following UAE, it is becoming increasingly evident that pregnancies after UAE are more risky especially during the early stages. Long-term outcome data from randomised trials involving UAE have very recently become available and show that whilst high satisfaction rates previously identified during early-stage followup are sustained, one notable drawback is a substantial risk of reintervention. It remains to be seen how this facet of UAE will impact on its future uptake.

Evaluating spindle assembly checkpoint competence in mouse oocytes using immunoblotting.

The spindle assembly checkpoint (SAC) is a quality control mechanism for overseeing the fidelity of chromosome segregation. By modulating the activity of the anaphase-promoting complex or cyclosome (APC/C), the SAC sets the timing of anaphase-onset by co-ordinating the timely destruction of key proteins with the completion of chromosome alignment. How mammalian oocytes regulate chromosome segregation during the first meiotic division (meiosis I) is of immense importance as mis-segregation at this crucial stage in human oocytes underpins the majority of human aneuploidy and birth defects. In recent years, the SAC has been shown to be indispensable for the accuracy of meiosis I chromosome segregation. Here, I describe a technique based on immunoblotting for evaluating SAC competence during meiosis I in mouse oocytes.

Uterine artery embolization for fibroids is associated with an increased risk of miscarriage.

OBJECTIVE: To investigate how uterine artery embolization (UAE) might alter the risk profile for pregnancies complicated by fibroids. DESIGN: Systematic literature review and meta-analysis of existing studies. SETTING: Academic reproductive medicine unit. PATIENT(S): Women with fibroids. INTERVENTION(S): A systematic literature review, raw data extraction, and data analysis. MAIN OUTCOME MEASURE(S): Rates of miscarriage, preterm delivery, malpresentation, intrauterine growth restriction (IUGR), cesarean delivery, and postpartum hemorrhage (PPH). RESULT(S): Two hundred twenty-seven completed pregnancies after UAE were identified. Miscarriage rates were higher in UAE pregnancies (35.2%) compared with fibroid-containing pregnancies matched for age and fibroid location (16.5%) (odds ratio [OR] 2.8; 95% confidence interval [CI] 2.0-3.8). The UAE pregnancies were more likely to be delivered by cesarean section (66% vs. 48.5%; OR 2.1; 95% CI 1.4-2.9) and to experience PPH (13.9% vs. 2.5%; OR 6.4; 95% CI 3.5-11.7). Rates of preterm delivery (14% vs. 16%; OR 0.9; 95% CI 0.5-1.5), IUGR (7.3% vs. 11.7%; OR 0.6; 95% CI 0.3-1.3), and malpresentation (10.4% vs. 13%; OR 0.8; 95% CI 0.4-1.5) were similar in UAE pregnancies and in control pregnancies with fibroids. CONCLUSION(S): The risk of miscarriage seems to be increased after UAE. In contrast, apart from an increased risk of abdominal delivery and PPH, critical adverse obstetric sequelae of IUGR and prematurity appear no more likely after UAE.

A spindle assembly checkpoint protein functions in prophase I arrest and prometaphase progression.

Two critical stages of mammalian oocyte regulation are prophase I arrest, which is important for sustaining the oocyte pool, and the progression through meiosis I (MI) to produce fertilizable eggs. We have found that the spindle assembly checkpoint protein BubR1 regulates both stages in mouse oocytes. We show that oocytes depleted of BubR1 cannot sustain prophase I arrest and readily undergo germinal vesicle breakdown, a marker for reentry into MI. BubR1-depleted oocytes then arrest before completing MI, marked by failure of polar body extrusion. Both meiotic defects in BubR1-depleted oocytes are due to reduced activity of the master regulator known as the anaphase-promoting complex (APC), brought about through diminished levels of the APC coactivator Cdh1.

Mad2 is required for inhibiting securin and cyclin B degradation following spindle depolymerisation in meiosis I mouse oocytes.

Mad2 is a pivotal component of the spindle assembly checkpoint (SAC) which inhibits anaphase promoting complex/cyclo-some (APC/C) activity by sequestering Cdc20 thereby regulating the destruction of securin and cyclin B. During mitosis, spindle depolymerisation induces a robust Mad2-dependent arrest due to inhibition of securin and cyclin B destruction. In contrast to mitosis, the molecular details underpinning the meiosis I arrest experienced by mouse oocytes exposed to spindle depolymerisation remain incompletely characterised. Notably, the role of Mad2 and the fate of the anaphase-marker, securin, are unexplored. As shown previously, we find that spindle depolymerisation by nocodazole inhibits first polar body extrusion (PBE) and stabilises cyclin B and cyclin-dependent kinase 1 activity in mouse oocytes. Here we show that stabilisation of cyclin B in nocodazole can be sustained for several hours and is associated with stabilisation of securin. These effects are SAC-mediated as, in oocytes depleted of the majority of Mad2 by morpholino antisense, securin and cyclin B are destabilised and 15% of oocytes undergo PBE. This reflects premature APC/C activation as a mutant form of cyclin B lacking its APC/C degradation signal is stable in Mad2-depleted oocytes. Moreover, homologues do not disjoin during the prolonged meiosis I arrest (> 18 h) induced by nocodaozole indicating that a non-cleavage mechanism is insufficient on its own for resolution of arm cohesion in mammalian oocytes. In conclusion, when all kinetochores lack attachment and tension, mouse oocytes mount a robust Mad2-dependent meiosis I arrest which inhibits the destruction of securin and cyclin B.

Restaging the spindle assembly checkpoint in female mammalian meiosis I.

In mammalian somatic cells, the spindle assembly checkpoint (SAC) is indispensable for ensuring the fidelity of chromosome segregation by delaying cell-cycle progression in the face of even a single misaligned chromosome. In contrast, the role of the SAC in unperturbed mammalian oocytes is less well defined as progression through meiosis I is unaltered in mouse oocytes in the presence of one or a few misaligned chromosomes. Furthermore, attempts to disable the function of the SAC protein, Mad2, in mouse oocytes have produced conflicting results. To gain further insight into SAC function during female mammalian meiosis I, we recently utilised a morpholino-based antisense approach to deplete the majority of Mad2 in mouse oocytes. Our results define a clear role for Mad2 in ensuring the proper timing of meiosis I events and ultimately, in ensuring the fidelity of homologue disjunction. We discuss the implications of these results for the regulation of meiosis I in mammalian oocytes and for the genesis of human aneuploidy.

Mad2 prevents aneuploidy and premature proteolysis of cyclin B and securin during meiosis I in mouse oocytes.

In mitosis, the spindle checkpoint protein Mad2 averts aneuploidy by delaying anaphase onset until chromosomes align. Here we show that depletion of Mad2 in meiosis I mouse oocytes induced an increased incidence of aneuploidy. Proteolysis of cyclin B and securin commenced earlier in Mad2-depleted oocytes, resulting in a shortened duration of meiosis I. Furthermore, overexpression of Mad2 inhibited homolog disjunction. We conclude that Mad2 delays the onset of cyclin B and securin degradation and averts aneuploidy during meiosis I in mammalian oocytes. The data suggest a link between trisomies such as Down syndrome and defective oocyte spindle checkpoint function.

Homologue disjunction in mouse oocytes requires proteolysis of securin and cyclin B1.

Disjunction of pairs of homologous chromosomes during the first meiotic division (MI) requires anaphase-promoting complex (APC)-mediated activation of separase in budding yeast and Caenorhabditis elegans, but not Xenopus laevis. It is not clear which model best fits the mammalian system. Here we show that homologue disjunction in mouse oocytes is dependent on proteolysis of the separase inhibitor securin and the Cdk1 regulatory sub-unit cyclin B1. Proteolysis of both proteins was entirely dependent on their conserved destruction box (D-box) motifs, through which they are targeted to the APC. These data indicate that the mechanisms regulating homologue disjunction in mammalian oocytes are similar to those of budding yeast and C.elegans.