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1.
Nat Rev Endocrinol ; 20(3): 149-167, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38110672

ABSTRACT

Infertility affects one in six couples, with in vitro fertilization (IVF) offering many the chance of conception. Compared to the solitary oocyte produced during the natural menstrual cycle, the supraphysiological ovarian stimulation needed to produce multiple oocytes during IVF results in a dysfunctional luteal phase that can be insufficient to support implantation and maintain pregnancy. Consequently, hormonal supplementation with luteal phase support, principally exogenous progesterone, is used to optimize pregnancy rates; however, luteal phase support remains largely 'black-box' with insufficient clarity regarding the optimal timing, dosing, route and duration of treatment. Herein, we review the evidence on luteal phase support and highlight remaining uncertainties and future research directions. Specifically, we outline the physiological luteal phase, which is regulated by progesterone from the corpus luteum, and evaluate how it is altered by the supraphysiological ovarian stimulation used during IVF. Additionally, we describe the effects of the hormonal triggers used to mature oocytes on the degree of luteal phase support required. We explain the histological transformation of the endometrium during the luteal phase and evaluate markers of endometrial receptivity that attempt to identify the 'window of implantation'. We also cover progesterone receptor signalling, circulating progesterone levels associated with implantation, and the pharmacokinetics of available progesterone formulations to inform the design of luteal phase support regimens.


Subject(s)
Luteal Phase , Progesterone , Pregnancy , Female , Humans , Luteal Phase/physiology , Chorionic Gonadotropin , Reproductive Techniques, Assisted , Fertilization in Vitro/methods , Ovulation Induction/methods
3.
Hum Fertil (Camb) ; 26(2): 266-275, 2023 Dec.
Article in English | MEDLINE | ID: mdl-35332836

ABSTRACT

This study aimed to discover whether egg sharing compromises the chance of donors or recipients achieving a live birth. A descriptive cohort study was performed of 4,545 fertility patients and 5,316 stimulation cycles at a London based fertility clinic between 2010 and 2019. There was no significant difference in clinical pregnancy rate (CPR) or live birth rate (LBR) between egg sharers and standard IVF patients or between egg sharing recipients and non-egg sharing recipients. Both egg sharers and their recipients had fewer oocytes and fewer day 3 embryos available for fresh embryo transfer or cryopreservation than standard IVF patients or non-egg sharing recipients. The cumulative LBR were significantly lower amongst egg sharers than standard IVF patients (p < 0.05), and significantly lower amongst egg sharing recipients than non-egg sharing recipients (p < 0.05). This study demonstrates that egg sharing does not compromise the chances of donors or their recipients achieving a live birth. However, participants may occasionally require additional ovarian stimulation cycles to conceive. With government funding for IVF treatment falling, egg sharing provides a practical option to allow more women access to IVF. Egg sharing is currently the most efficient way of maximising the use of the precious resource of human oocytes.


Subject(s)
Fertilization in Vitro , Live Birth , Pregnancy , Humans , Female , Cohort Studies , Embryo Transfer , Pregnancy Rate , Birth Rate , Retrospective Studies
4.
J Med Educ Curric Dev ; 9: 23821205211072722, 2022.
Article in English | MEDLINE | ID: mdl-35047669

ABSTRACT

OBJECTIVES: The objectives of this study were the following: (i) assess interest levels in cardiothoracic surgery (CTS) among UK-based medical students, (ii) identify potential motivators and barriers to pursuing CTS training, (iii) explore the influence of gender on interest in CTS in greater depth. METHODS: Medical students from all year groups across UK medical schools were invited to participate in a cross-sectional, national online survey. Responses were collected from 02/12/2019 to 08/12/2019. RESULTS: 1675 medical students from 31 UK medical schools responded, with an estimated 5.3% response rate. Of the respondents, 33.7% respondents reported having exposure to CTS, primarily through their medical school or through extracurricular activities (48.4% and 38.8%, respectively). When assessing interest in CTS, 31.4% were interested in undertaking a career in CTS, with a larger proportion of students expressing interest with no exposure to CTS than those with exposure. However, interest in pursuing CTS decreased with exposure as medical students transitioned from pre-clinical to clinical stages. Additionally, male participants were more interested in seeking a CTS post than their female counterparts (38% vs. 27.6%). The length of training (p = 0.0009) and competitive nature (p < 0.0001) of gaining a CTS post were the primary deterring factor for female participants, compared to their male counterparts. CONCLUSIONS: This study shows the importance of quality of exposure and its impact on students' interests in pursuing a career in CTS. The negative relationship between exposure and interest in CTS can be associated with the realisation of the challenges that come with pursuing CTS.

5.
BMJ Open ; 10(11): e042378, 2020 11 05.
Article in English | MEDLINE | ID: mdl-33154063

ABSTRACT

OBJECTIVES: To investigate perceptions of medical students on the role of online teaching in facilitating medical education during the COVID-19 pandemic. DESIGN: Cross-sectional, online national survey. SETTING: Responses collected online from 4th May 2020 to 11th May 2020 across 40 UK medical schools. PARTICIPANTS: Medical students across all years from UK-registered medical schools. MAIN OUTCOME MEASURES: The uses, experiences, perceived benefits and barriers of online teaching during the COVID-19 pandemic. RESULTS: 2721 medical students across 39 medical schools responded. Medical schools adapted to the pandemic in different ways. The changes included the development of new distance-learning platforms on which content was released, remote delivery of lectures using platforms and the use of question banks and other online active recall resources. A significant difference was found between time spent on online platforms before and during COVID-19, with 7.35% students before versus 23.56% students during the pandemic spending >15 hours per week (p<0.05). The greatest perceived benefits of online teaching platforms included their flexibility. Whereas the commonly perceived barriers to using online teaching platforms included family distraction (26.76%) and poor internet connection (21.53%). CONCLUSIONS: Online teaching has enabled the continuation of medical education during these unprecedented times. Moving forward from this pandemic, in order to maximise the benefits of both face-to-face and online teaching and to improve the efficacy of medical education in the future, we suggest medical schools resort to teaching formats such as team-based/problem-based learning. This uses online teaching platforms allowing students to digest information in their own time but also allows students to then constructively discuss this material with peers. It has also been shown to be effective in terms of achieving learning outcomes. Beyond COVID-19, we anticipate further incorporation of online teaching methods within traditional medical education. This may accompany the observed shift in medical practice towards virtual consultations.


Subject(s)
COVID-19/epidemiology , Education, Distance/methods , Education, Medical, Undergraduate/methods , Internet , SARS-CoV-2 , Schools, Medical , Students, Medical , Cross-Sectional Studies , Female , Humans , Learning , Male , Pandemics , Surveys and Questionnaires , United Kingdom
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