natural cycle
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2022 ◽  
Vol 16 ◽  
pp. 263349412110620
Federica Di Guardo ◽  
Christophe Blockeel ◽  
Michel De Vos ◽  
Marco Palumbo ◽  
Nikolaos Christoforidis ◽  

About 20% of women undergoing in vitro fertilization struggle with poor ovarian response, indicating a poor prognosis related to low response following ovarian stimulation. Indeed, poor ovarian response, that is associated with both high cancelation rates and low live birth rates, still represents one of the most important therapeutic challenges in in vitro fertilization. In this context, natural cycle/modified natural cycle– in vitro fertilization, as a ‘milder’ approach, could be a reasonable alternative to high-dose/conventional ovarian stimulation in poor ovarian responders, with the aim to retrieve a single oocyte with better characteristics that may result in a single top-quality embryo, transferred to a more receptive endometrium. Moreover, modified natural cycle– in vitro fertilization may be cost-effective because of the reduced gonadotropin consumption. Several studies have been published during the last 20 years reporting conflicting results regarding the use of natural cycle/modified natural cycle– in vitro fertilization in women with poor ovarian response; however, while most of the studies concluded that mild stimulation regimens, including natural cycle/modified natural cycle– in vitro fertilization, have low, but acceptable success rates in this difficult group of patients, others did not replicate these findings. The aim of this narrative review is to appraise the current evidence regarding the use of natural cycle/modified natural cycle– in vitro fertilization in poor ovarian responders.

2021 ◽  
Vol 2114 (1) ◽  
pp. 012019
Adi Al A’assam ◽  
M.W. Ahamd

Abstract When studying the water reality and calculating the increase in the quantities of water per year, we find that there is another way to increase the percentage of water, and that is through optical reproduction. For a detailed explanation of the location of water on Earth, see the map and the data table shown below. Note that the world’s add up to water supply is almost 1.387 million cubic kilometers (332.6 cubic miles) of wate, of which more than 96% is salt water. As for fresh water, more than 96% are trapped by rivers and glaciers, and 30% are on the ground. As for the freshwater resources represented in rivers and lakes, they constitute about 93,100 cubic kilometers (22,300 cubic miles), which is about 1/150 of 1% of the total water. Rivers and lakes still make up most of the water sources that people use daily. The amount of water stored in the oceans for long periods is much more than that which moves through the water cycle. The total water supply worldwide is 1,386,000,000 cubic kilometers (321,000,000 cubic miles), of which 1,338,0, 000 cubic kilometers (332,500,000 cubic miles) are stored in the oceans at a rate of 95%, as the oceans give almost 90% of the water. Dissipated that goes to the water cycle. The photonic cloning resulting by the sun contributes to the consistency of water level. Indeed, the consistency of ocean water depends not only on the natural cycle of evaporation process of those waters to return to the oceans again, but also on the photonic cloning resulting by the sun, as experiment has vividly shown.

2021 ◽  
Vol 19 (1) ◽  
María del Carmen Nogales ◽  
María Cruz ◽  
Silvia de Frutos ◽  
Eva María Martínez ◽  
María Gaytán ◽  

Abstract Background The goal of this study was to investigate which factors, excluding embryo aneuploidies, are associated with miscarriage in patients who have undergone a single euploid blastocyst transfer. Methods Retrospective, observational and multicenter study with 2832 patients undergoing preimplantational genetic testing for aneuploidies (PGT-A) due to repeated implantation failure, recurrent pregnancy loss, advanced maternal age or severe male factor were transferred one single euploid embryo. Results One of the main findings was a significant relationship between body mass index (BMI) and miscarriage rates (13.4% in underweight women, 12.1% in normal weight, 14.5% in overweight, and 19.2% in obese women, odds ratio [OD] 1.04; 95% confidence interval [CI], 1.01–1.07 p = 0.006). Endometrial thickness (OD 0.65; 95%, 0.52–0.77 p = 0.04) and type of endometrial preparation (natural cycle or hormone replacement cycle) (OD 0.77; 95%, 0.52–0.77, p = 0.04) were also associated with miscarriage rates. Conclusions BMI was strongly associated to miscarriage rates. We also observed a weaker association with endometrial thickness and with the type of endometrial preparation (natural cycle or hormone replacement cycle). None of the other studied variables (biopsy day, maternal and male age, duration of infertility, cycle length, previous miscarriages, previous live births, previous In Vitro Fertilization (IVF) cycles, endometrial pattern and/or diagnosis) were associated with miscarriage rates.

2021 ◽  
Vol 2 (2) ◽  
pp. 185-198
Baiq Ismiwati ◽  
Taufik Chaidir ◽  
Ida Ayu Putri.S ◽  
Siti Sriningsih

Zero waste is an ethical, economical, efficient and visionary goal, to guide people in changing their lifestyles and practices in imitation of a sustainable natural cycle, where all materials that are no longer used are designed to be a resource for others to use (en. Problems related to waste in Sandik Village are: 1. Non-organic waste is relatively widely scattered in the Sandik Village environment; 2. The waste bank is not yet operational; 3. People do not know much about non-organic waste which can be used as raw material for creative products that have a selling value; 4. The Sandik Village PKK Team does not have the skills to process non-organic waste into handicraft products with economic value. The aim of this service is to empower the Sandik Village PKK Driving Team in processing non-organic waste into goods that have economic value. The service method is carried out with lectures, discussions, and technical training on processing non-organic waste into products with sale value. The results of the activity: there were several participants who were able to make products at the end of the training; Participants were willing and enthusiastic to pass it on to other mothers around the village. It can be concluded that this service activity was successful, as shown by: Participants were able to sort between organic and non-organic waste and increased participants' knowledge about some of the non-organic waste that they produce every day can be used and processed into useful and economic value items

А. Х. Аласханов

В работе приводятся возможности расширения сырьевой базы для получения качественных и прочных строительных композитов. Приводится понятие о ресурсном цикле, основанном на природном круговороте веществ (ПКВ) и обеспечивающем безотходный замкнутый цикл производства композитов. Обозначена актуальность и перспективность перехода на энерго- и ресурсосберегающие технологии безотходного производства. The paper presents the possibilities of expanding the raw material base to obtain high-quality and durable building composites. The concept of a resource cycle based on the natural cycle of substances (PCR) and providing a waste-free closed cycle for the production of composites is given. The relevance and prospects of the transition to energy- and resource-saving technologies of waste-free production are indicated.

2021 ◽  
pp. 1-12
Hsien-Wang Ou

Abstract In Part 1, we have considered the dynamics of topographically confined glaciers, which may undergo surge cycles when the bed becomes temperate. In this Part 2, we consider the ice discharge over a flatbed, which would self-organize into alternating stream/ridge pairs of wet/frozen beds. The meltwater drainage, no longer curbed by the bed trough, would counter the conductive cooling to render a minimum bed strength at some intermediate width, toward which the stream would evolve over centennial timescale. At this stationary state, the stream width is roughly twice the geometric mean of the stream height and length, which is commensurate with its observed width. Over a flatbed, streams invariably interact, and we deduce that the neighboring ones would exhibit compensating cycles of maximum velocity and stagnation over the centennial timescale. This deduction is consistent with observed time variation of Ross ice streams B and C (ISB/C), which is thus a manifestation of the natural cycle. Moreover, the model uncovers an overlooked mechanism of the ISC stagnation: as ISB widens following its reactivation, it narrows ISC to augment the loss of the meltwater, leading to its stagnation. This stagnation is preceded by ice thickening hence opposite to the thinning-induced surge termination.

2021 ◽  
Vol 8 ◽  
Dan-Dan Gao ◽  
Li Li ◽  
Yi Zhang ◽  
Xiao-Xuan Wang ◽  
Jing-Yan Song ◽  

Objective: The aim of this study is to investigate, in ovulatory patients, whether there is a difference in reproductive outcomes following frozen-thawed embryo transfer (FET) in natural cycles (NC) compared to modified natural cycles (mNC).Methods: This retrospective cohort study, performed at the public tertiary fertility clinic, involved all infertile patients undergoing endometrial preparation prior to FET in NC and mNC from January, 2017 to November, 2020. One thousand hundred and sixty-two patients were divided into two groups: mNC group (n = 248) had FET in a NC after ovulation triggering with human chorionic gonadotropin (hCG); NC group (n = 914) had FET in a NC after spontaneous ovulation were observed. The primary outcome was live birth rate. All pregnancy outcomes were analyzed by propensity score matching (PSM) and multivariable logistic regression analyses.Results: The NC group showed a higher live birth rate [344/914 (37.6%) vs. 68/248 (27.4%), P = 0.003; 87/240 (36.3%) vs. 66/240 (27.5%), P = 0.040] than the mNC group before and after PSM analysis. Multivariable analysis also showed mNC to be associated with a decreased likelihood of live birth compared with NC [odds ratio (OR) 95% confidence interval (CI) 0.71 (0.51–0.98), P = 0.039].Conclusion: For women with regular menstrual cycles, NC-FET may have a higher chance of live birth than that in the mNC-FET cycles. As a consequence, it's critical to avoid hCG triggering as much as possible when FETs utilize a natural cycle strategy for endometrial preparation. Nevertheless, further more well-designed randomized clinical trials are still needed to determine this finding.

T R Zaat ◽  
J P de Bruin ◽  
M Goddijn ◽  
M van Baal ◽  
E B Benneheij ◽  

Abstract STUDY QUESTIONS The objective of this trial is to compare the effectiveness and costs of true natural cycle (true NC-) frozen embryo transfer (FET) using urinary LH tests to modified NC-FET using repeated ultrasound monitoring and ovulation trigger to time FET in the natural cycle. Secondary outcomes are the cancellation rates of FET (ovulation before hCG or no dominant follicle, no ovulation by LH urine test, poor embryo survival), pregnancy outcomes (miscarriage rate, clinical pregnancy rates, multiple ongoing pregnancy rates, live birth rates, costs) and neonatal outcomes (including gestational age, birthweight and sex, congenital abnormalities or diseases of babies born). WHAT IS KNOWN ALREADY FET is at the heart of modern IVF. To allow implantation of the thawed embryo, the endometrium must be prepared either by exogenous estrogen and progesterone supplementation (artificial cycle (AC)-FET) or by using the natural cycle to produce endogenous oestradiol before and progesterone after ovulation to time the transfer of the thawed embryo (NC-FET). During a NC-FET, women visit the hospital repeatedly and receive an ovulation trigger to time FET (i.e. modified (m)NC-FET or hospital-based monitoring). From the woman’s point of view, a more natural approach using home-based monitoring of the ovulation with LH urine tests to allow a natural ovulation to time FET may be desired (true NC-FET or home-based monitoring). STUDY DESIGN, SIZE, DURATION This is a multicentre, non-inferiority prospective randomised controlled trial design. Consenting women will undergo one FET cycle using either true NC-FET or mNC-FET based on randomisation. PARTICIPANTS/MATERIALS, SETTING, METHODS Based on our sample size calculation the study group will consist of 1464 women between 18 and 45 years old who are scheduled for FET. Women with anovulatory cycles, women who need ovulation induction and women with a contra indication for pregnancy will be excluded. The primary outcome is ongoing pregnancy. Secondary outcomes are cancellation rates of FET, pregnancy outcomes (including miscarriage rate, clinical pregnancy, multiple pregnancy rate and live birth rate). Costs will be estimated by counting resource use and calculating unit prices. STUDY FUNDING/COMPETING INTEREST(S) The study received a grant from The Dutch Organisation for Health Research and Development (ZonMw 843002807; ZonMw has no role in the design of the study, collection, analysis, and interpretation of data or writing of the manuscript. Dr. Broekmans reports personal fees from member of the external advisory board for Merck Serono, grants from Research support grant Merck Serono, outside the submitted work;. Dr. Cantineau reports and Unrestricted grant of Ferring B.V. to the Center for Reproductive medicine, no personal fee. Author up-to-date on Hyperthecosis. Congress meetings 2019 with Ferring B.V. and Theramex B.V. Dr. Goddijn reports Department research and educational grants from Guerbet, Merck and Ferring (location VUMC) outside the submitted work. Dr. Groenewoud reports personal fees from Titus Health Care, outside the submitted work; Dr. Lambalk reports grants from Ferring, grants from Merck, from Guerbet, outside the submitted work. The other authors have none to declare. TRIAL REGISTRATION NUMBER Dutch Trial Register (Trial NL6414 (NTR6590), TRIAL REGISTRATION DATE 23 July 2017 DATE OF FIRST PATIENT’S ENROLMENT 10 April 2018

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