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Welcome to The Visible Embryo, a comprehensive educational resource on human development from conception to birth.

The Visible Embryo provides visual references for changes in fetal development throughout pregnancy and can be navigated via fetal development or maternal changes.

The National Institutes of Child Health and Human Development awarded Phase I and Phase II Small Business Innovative Research Grants to develop The Visible Embryo. Initally designed to evaluate the internet as a teaching tool for first year medical students, The Visible Embryo is linked to over 600 educational institutions and is viewed by more than one million visitors each month.

Today, The Visible Embryo is linked to over 600 educational institutions and is viewed by more than 1 million visitors each month. The field of early embryology has grown to include the identification of the stem cell as not only critical to organogenesis in the embryo, but equally critical to organ function and repair in the adult human. The identification and understanding of genetic malfunction, inflammatory responses, and the progression in chronic disease, begins with a grounding in primary cellular and systemic functions manifested in the study of the early embryo.

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The World Health Organization (WHO) has created a new Web site to help researchers, doctors and patients obtain reliable information on high-quality clinical trials. Now you can go to one website and search all registers to identify clinical trial research underway around the world!




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Pregnancy Timeline by SemestersFetal liver is producing blood cellsHead may position into pelvisBrain convolutions beginFull TermWhite fat begins to be madeWhite fat begins to be madeHead may position into pelvisImmune system beginningImmune system beginningPeriod of rapid brain growthBrain convolutions beginLungs begin to produce surfactantSensory brain waves begin to activateSensory brain waves begin to activateInner Ear Bones HardenBone marrow starts making blood cellsBone marrow starts making blood cellsBrown fat surrounds lymphatic systemFetal sexual organs visibleFinger and toe prints appearFinger and toe prints appearHeartbeat can be detectedHeartbeat can be detectedBasic Brain Structure in PlaceThe Appearance of SomitesFirst Detectable Brain WavesA Four Chambered HeartBeginning Cerebral HemispheresFemale Reproductive SystemEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterSecond TrimesterFirst TrimesterFertilizationDevelopmental Timeline
CLICK ON weeks 0 - 40 and follow along every 2 weeks of fetal development
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Home | Pregnancy Timeline | News Alerts |News Archive Jan 29, 2014

Hyperthyroidism is associated with a delay in reaching sexual maturity in children
and later in adults with menstrual problems or even  failure to ovulate.
However, despite this long association, national guidlines do not currently recommend
routine measurement of thyroid function in women with problems conceiving.




Effects of thyroid disorders on reproductive health

Thyroid disease can significantly affect a woman's ability to have children. A new review of the disease promotes thyroid screening for all women wanting to begin their families.

A review of the effects of thyroid disease on fertility was published in The Obstetrician & Gynaecologist (TOG), examining the current evidence on how to optimise thyroid function and improve pregnancies.

The thyroid controls metabolism through two hormones: thyroxine and triiodothyronine. These hormones are key to growth and development, particularly brain development. Changes in thyroid function can impact reproductive function before, during and after conception. The disease is divided into hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid) each beginning from numerous causes.

Hyperthyroidism is found in approximately 2.3% of women with fertility problems, compared to 1.5% of women generally. The condition is linked with menstrual irregularity and affects around 0.5% of women of reproductive age. Hypothyroidism is associated with a delay in reaching sexual maturity in children and in adults with menstrual problems or even the lack of ovulation. However, despite this long association, national guidlines do not currently recommend routine measurement of thyroid function in women who have problems conceiving.

Review authors note that miscarriage now affects about one in five pregnancies and recurrent miscarriage, such as three consecutive miscarriages, affects 1% of couples. Thyroid hormone plays an important role in embryo development and changes in thyroid levels have long been associated with miscarriage. Hyperthyroidism has significant adverse affects on pregnancy including: preterm delivery, pre-eclampsia, growth restriction, heart failure and stillbirth.

The authors therefore suggest screening for thyroid disease in women with fertility problems or with recurrent pregnancy loss. Additionally, they suggest routine screening for thyroid dysfunction at the start of every pregnancy may prove beneficial.

Women diagnosed with thyroid disease are advised by the authors to continue their medication throughout their pregnancy while receiving close monitoring. Adds Amanda Jefferys, co-author from the Bristol Centre for Reproductive Medicine, Southmead Hospital, Bristol UK: "Abnormalities in thyroid function can have an adverse effect on reproductive health resulting in reduced rates of conception, increased miscarriage risk and adverse pregnancy and neonatal outcomes. However, with appropriate screening and prompt management, these risks can be significantly reduced."

"Thyroid disease is common in reproductive medicine, in fact, it is the most common endocrine condition affecting women of reproductive age. This paper highlights how thyroid disorders can affect fertility and pregnancy and makes a case for universal screening."

Jason Waugh, TOG Editor-in-chief

Key content
Thyroid disease is a common condition in the reproductive medicine setting due to the complex interplay between the hypothalamo-pituitary axis and the thyoid gland.

Abnormalities in thyroid function, including hyperthyroidism and hypothyroidism, can have an adverse effect on reproductive health and result in reduced rates of conception, increased early pregnancy loss, and adverse pregnancy and neonatal outcomes.

There is increasing evidence for the role of autoantibodies in subfertility and early pregnancy loss, even in euthyroid women.

Evidence suggests that treating thyroid disorders and keeping thyroid-stimulating hormone levels at the lower end of normal in euthyroid women may improve conception rates in subfertile women and reduce early pregnancy loss.

Learning objectives
To gain an overview of the effect of thyroid disorders on reproductive health.
To review the evidence on how to optimise thyroid function to improve reproductive outcomes.

Ethical issues
Screening for thyroid disease should be considered in women presenting with subfertility and recurrent early pregnancy loss.

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