Vitrification of Oocytes & Embryos by Suzanne Cawood Part 2 – Video

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Vitrification of Oocytes Embryos by Suzanne Cawood Part 2
This lecture was part of the scientific program of IVF Lite 2011, which was held in August 2011 at Radisson Blu Resort, Goa. The landmark conference was sponsored by the IVF Lite Foundation...

By: IVF Lite Foundation

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Vitrification of Oocytes & Embryos by Suzanne Cawood Part 2 - Video

human reproduction – eschooltoday

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Introduction to sexual reproduction Almost every growing up person has wondered where babies come from. If you are learning with us today, then you are probably a grown up kid and hopefully, you shall understand this bundle of excitement, and you shall learn to be more responsible in your boy-girl activities.

Reproduction generally means the action or process of making a copy of something. Human reproduction, specifically, is a wonderful, natural instance of humans making new humans (offspring) or giving birth to new humans (babies).

Reproduction is necessary for continuity of humans. This means without it, humans will no longer exist, as there will be no replacement when we grow very old and die.

There are two types of reproduction in living things

involves two individuals of the same species, usually a male and female. Asexual reproduction can occur without the involvement of another, and this is usually found in single cell organisms and in some plants.

As children grow up to become adults, their brains work with their reproductive organs to get them ready reproduce. This sexual development process takes time and it is called puberty. To understand this lesson, make sure to read about these: (Puberty For Boys, Puberty for Girls and Menstruation)

Let us start by looking at the female reproductive organ.

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human reproduction - eschooltoday

Keep calm and… stop? Fertility treatment in a pandemic – BioNews

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16 March 2020

The spread of a novel coronavirus (SARS-CoV-2), which causes the disease COVID-19, presents UK fertility clinics and patients with a unique set of challenges. Some of this is because we simply don't know enough about the effects of the infection on fertility, fertility treatment and early pregnancy. Early data, summarised in the Royal College of Obstetricians and Gynaecologists guidance, are reassuring, but the number of reported cases is still small.

Clinics could face logistical challenges if large numbers of staff are unable to work due to quarantine requirements, or if elective work in hospitals is shut down to make space for emergencies. Should this prospect impact the advice we give patients? The UK Government, at the time of writing, has held back from the more radical social distancing measures implemented in other countries. This leaves clinics with a dilemma of whether to continue to offer fertility treatment to unaffected patients, or to go beyond current Government advice and suspend services.

Patients' anxieties are understandable and those who wish to delay their treatment should be accommodated. It makes sense for anyone who meets the criteria for self-isolation (which are also evolving as we write) to be advised not to start treatment and indeed to stop active treatment if already commenced.

Some would go further and say that all elective fertility treatment should be delayed. The European Society forHuman Reproduction and Embryology advises that all fertility patients should 'avoid becoming pregnant at this time'. A Twitter poll targeting reproductive medicine clinicians found 45.5 percent support for delaying frozen embryo replacement in patients in areas with a high COVID-19 burden.

The question then arises, for how long should treatment be delayed? It is reported that the UK will see the peak of infections three months from now, with a tail persisting into the autumn and a potential second peak after this. If we were to delay all fertility treatment, UK clinics may struggle with the capacity to cope with demand when treatments re-start. One could easily envisage a delay of six months, which may well harm the chances of conception for some patients. Hence the need for advice to be tailored to each individual patient's situation. Delaying treatment, in effect closing clinics, would have other impacts including financial strain (particularly for smaller stand-alone clinics) and loss of morale among the more vulnerable fertility patients.

Furthermore, Chinese researchers have identified that testicular Leydig cells and seminiferous tubules express the angiotensin-converting enzyme 2 (ACE2) receptor, which is used by the virus to gain entry into cells. This short discussion paper has not been peer-reviewed and there is no evidence to suggest that the virus is found in the testes, as reported in BioNews 1039. However, this paper does alert to the need for further research into whether male fertility may be affected by COVID-19, so that patients can be adequately counselled.

The fact is that this is a fast-moving situation, with facts and knowledge changing daily. This makes it hard for professional bodies to issue meaningful guidance to practitioners and patients. The American Society for Reproductive Medicine even calls its guidance 'suggestions', showing the tentative nature of such advice. As far as UK clinics are concerned, unless restriction of movement is introduced, it is reasonable to continue treatment for those who are well and wish to continue. However, centres must be prepared to terminate or complete treatment (including through cycle cancellation, oocyte or embryo freezing) and cease initiating new treatments as and when 'lock-down' commences.

Clinicians have in their toolbox measures, which can be taken proactively, to reduce the risk to patients who find themselves in a situation where treatment has to stop. A patient may develop symptoms, or fall into a risk group, for COVID-19 after having started ovarian stimulation. Patients on a g onadotropin-releasing hormone (GnRH) antagonist regime could be managed by stopping follicle-stimulating hormone (FSH) administration and continuing antagonist administration until the patient's ovarian response has settled. Data from small case studies indicate that GnRH antagonist continuation after the trigger of final oocyte maturation is effective in reducing the risk of ovarian hyperstimulation syndrome (OHSS). Where concern exists about a high ovarian reserve, consideration should be given to co-treatment with letrozole, keeping oestradiol levels low and reducing concern about the risk of OHSS.

The key is anticipation of problems, both clinical and organisational. All centres should have a contingency plan in place that describes a stepwise reduction in their activities. This allows prioritisation down to a minimal activity if needed. It is unlikely that any licensed fertility clinic can shut down completely; work goes on behind the scenes, in particular around the maintenance of storage banks. There are practical considerations for this maintaining tanks for example but also the regulatory issues around consent expiry and data management. Urgent medical issues will still arise, and it may be appropriate to maintain a fertility preservation service for cancer patients. This prioritisation must take into account national and local pandemic policies, as well as recognition of likely reduced levels of staffing due to illness and isolation. Mitigation policies may include replacing consultations with phone- or video-calls and making sure there is a good communication policy for patients who have treatment-related problems.

We must also bear in mind the anxiety that is generated by how this pandemic is playing out. In our connected world, news, including fake news, travels faster than the virus. It is hard to escape the sense of a storm looming or a tidal wave about to break. In some countries, of course, the storm is now raging and the tide has overwhelmed even well-resourced health systems.

Fittingly for the first pandemic of the social media age, there have been extensive informal discussions on these issues among clinicians across many social media platforms. US colleagues have collated a number of measures, gleaned from social media, that clinics should consider in their response to this challenge.

Things are moving apace, and we must respond in a safe and effective way, but without panic. The British Fertility Society and the Association of Reproductive Clinical Scientists are committed to providing guidance to UK clinics as the situation evolves.

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Keep calm and... stop? Fertility treatment in a pandemic - BioNews

HUMAN REPRODUCTION – leavingbio.net

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HUMAN REPRODUCTION

As in all other organisms reproduction is the formation of new individuals of the same species. Sexual

reproduction is the only method of reproduction in our species. Sexual reproduction involves the fusion of specialised haploid sex cells. The fusion of sperm and egg cell is called fertilisation. Fertilisation results in the formation of a diploid zygote from which a new individual develops.

Reproductive Structures

Both the male and female reproductive structures have 3 levels of organisation:

1. Production of sex cells.

2. Transport tubes.

3. Glands to secrete hormones.

The Male Reproductive System

The gonad is the name for the organ that produces sex cells in organs. The male gonads are called the testes.

The testes are contained in the scrotum.

The testes produce the sperm cells by meiosis. The temperature must be lower than body temperature for this to occur. There are tubules that are lines with sperm producing cells. Testosterone, the male sex hormone, is also produced in the testes. Once the sperm are produced they mature in the epidymis. This structure is located outside of the testis. If they are not released within about 6 weeks they are broken down and released to the bloodstream by a process called resorption. The sperm are carried to the urethra by the sperm duct. The urethra carries both sperm and urine.

The sperm cells are carried within a liquid called semen. The semen is produced by the seminal vescicles, the

prostate gland, and Cowpers glands. The semen also contains nourishment for the sperm cells.

Sperm cells are released by ejaculation. About 50-300 million sperm cells are released at one time.

Sperm cells, also called spermatozoa, are haploid containing 23 chromosomes. Their production begins at puberty.

The penis is adapted to place sperm cells into the female. The tip is called the glans. Erection occurs when blood rushes into the penis.

THE STRUCTURE OF THE SPERM CELL

Watch an animation about sperm production.

Take some online quizzes on the male reproductive parts.

Quiz # 1

Quiz # 2

Quiz # 3

Quiz # 4

MALE HORMONES

Male hormones are produced by the pituitary gland during puberty. They are:

TESTOSTERONE

During the period of pregnancy testosterone causes the development of primary male sex characteristics. These include the development of the penis and the other male reproductive parts.

Later in life, at puberty, testosterone causes the enlargement of the reproductive parts as well as the development of secondary sexual characteristics. These are characteristics that distinguish males from females.

Male secondary sexual characteristics included:

2. enlarged larynx producing a deeper voice

3. wider shoulders

4. greater skeletal muscular development

5. growth in height and weight

MALE INFERTILITY

The most common cause of male infertility is the low production of sperm. There are many causes of low sperm production. Stress, alcohol and drug abuse, high temperature of the testes, and low testosterone production are all causes.

THE FEMALE REPRODUCTIVE SYSTEM

OVARIES

Ovaries produce eggs and female hormones. At puberty there are about 40,000 diploid eggs. Each egg is enclosed in a group of cells called a follicle. About 20 haploid eggs are produced each month. Usually all but one die. The haploid egg cell is called the ovum and is surrounded by the Graafian follicle which produces the female hormone called oestrogen. Ovulation is the release of the egg from the follicle. This occurs when the follicle bursts.

FALLOPIAN TUBES

The fallopian tubes are about 12 cm long and have ends that are funnel shaped. These ends collect the egg after ovulation. Cilia and peristalsis move the egg along the tube. The egg will die in the tube if it is not fertilised.

UTERUS

The uterus, also known as the womb, is made of involuntary muscle. It is lines with the endometrium. This lining thickens with cells and blood every month. This happens in order to nourish the embryo (if present). The opening of the uterus is called the cervix.

VAGINA

The vagina is a muscular tube which allows the sperm to enter the female as well as the baby to exit. It is lined with mucous secreting cells. The uretrhra opens near the vagina. The vagina is protected by folds of skin called the vulva. The hymen partially blocks the entrance of the vagina. It is broken by sexual intercourse or with the use of tampons.

Take some short online quizzes on the female reproductive parts:

Quiz # 1

Quiz # 2

Quiz # 3

Quiz # 4

Quiz # 5

THE MENSTRUAL CYCLE

The menstrual cycle occurs every 28 days from puberty to menopause (the end of the females reproductive life). It occurs only if fertilisation of the egg has not taken place.

The typical events of the menstrual cycle are:

Day 1 to day 5-

a. The endometrium breaks down and is shed from the body. This is called menstruation.

b. Meiosis occus in the ovary to produce a new egg surrounded by the Graafian follicle.

Day 6 to day 13-

a. Oestrogen is produced by the Graafian follicle. Oestrogen also stimulates the endometrium to thicken again. One Graafian follicle with one egg develops.

b. Oestrogen stimulates the production of LH (leuteinising hormone)

Day 14-

a. The surge of LH stimulates ovulation.

b. The egg enters the funnel of the Fallopian tube. It can be fertilised for the next 48 hours.

Day 15 to day 26-

a. The corpus luteum (yellow body) develops from the remains of the Graafian follicle. This produced progesterone and some oestrogen. The progesterone causes the endometrium to continue to thicken. It also prevents new eggs from forming.

b. The egg that was released at day 14 will die if it is not fertilised.

c. If fertilisation did not take place the corpus luteum begins to degenerate.

Day 26 to day 28-

a. Oestrogen and progesterone levels decline.

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HUMAN REPRODUCTION - leavingbio.net