Welcome to The Visible Embryo

Home- - -History-- -Bibliography- -Pregnancy Timeline- --Prescription Drugs in Pregnancy- -- Pregnancy Calculator- --Female Reproductive System- News Alerts -Contact

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 ' million visitors each month.


WHO International Clinical Trials Registry Platform
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!



Home

History

Bibliography

Pregnancy Timeline

Prescription Drug Effects on Pregnancy

Pregnancy Calculator

Female Reproductive System

Contact The Visible Embryo

News Archive
Disclaimer: The Visible Embryo web site is provided for your general information only. The information contained on this site should not be treated as a substitute for medical, legal or other professional advice. Neither is The Visible Embryo responsible or liable for the contents of any websites of third parties which are listed on this site.
Content protected under a Creative Commons License.

No dirivative works may be made or used for commercial purposes.

Return To Top Of Page
Pregnancy Timeline by SemestersFemale Reproductive SystemFertilizationThe Appearance of SomitesFirst TrimesterSecond TrimesterThird TrimesterFetal 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 HemispheresEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterDevelopmental Timeline
Click weeks 0 - 40 and follow fetal growth
Search artcles published since 2007

November 8, 2012--------News Archive Return to: News Alerts


Dr Bentzen: "Epidemiological studies have established a link between the age at
menopause among mothers and daughters. In line with the suggested 20-year interval
between the first decline in fertility and the menopause, we hypothesised that maternal
factors may also impact a woman's fertility potential in terms of available eggs."






WHO Child Growth Charts

       

Mothers’ Age at Menopause May Predict Daughters’ Ovarian Reserve

A mother's age at menopause may predict her daughter's fertility in terms of the numbers of eggs remaining in her ovaries, according to new research

By assessing ovarian reserve with two accepted methods – levels of anti-Müllerian hormone (AMH) and antral follicle count (AFC) – in daughters and comparing it with the age of menopause in their mothers, researchers found that both AMH and AFC declined faster in women whose mothers had an early menopause compared to women whose mothers had a late menopause.

The number of eggs remaining in a woman's ovary is related to a reduction in her ability to conceive naturally, with both the number and quality of eggs starting to decline as she gets older.


"This is the first study to suggest that
the age-related decline of AMH and AFC
may differ between those whose mothers
entered menopause before the age of 45 years
and those whose mothers entered menopause
after the age of 55 years.

Our findings support the idea that the ovarian
reserve is influenced by hereditary factors.
However, long-term follow-up studies are required.

Conclusive evidence can only be obtained when we
have longitudinal studies that follow women who have
AMH measurements over time until menopause.
Therefore, interpretations of our data are limited
and the findings we have described may
not occur in any given individual."

Dr. Janne Bentzen
Copenhagen University Hospital, Rigshospitalet
Copenhagen, Denmark
research leader


The work is published online in Europe's leading reproductive medicine journal Human Reproduction [1].

Previous research has suggested that there is about 20 years between a woman's fertility starting to decline and the onset of menopause. So a woman who enters the menopause at 45 may have experienced a decline in her fertility at the age of 25.

Dr Bentzen: "Epidemiological studies have established a link between the age at menopause among mothers and daughters. In line with the suggested 20-year interval between the first decline in fertility and the menopause, we hypothesised that maternal factors may also have an impact on a woman's fertility potential in terms of ovarian reserve."

The researchers recruited 527 women working in health care at the Copenhagen University Hospital, who were aged between 20-40 years and whose mothers' age at natural menopause was known. They divided them into three categories: those whose mothers had an early menopause (younger than 45); normal maternal age at menopause (46-54 years); and late maternal age at menopause (older than 55).


Transvaginal sonography was used to count the number
of antral follicles in the women's ovaries. Follicles are
clusters of cells that contain the immature egg.

Every woman is born with about two million follicles,
but only 400 will ever mature enough to release an egg
for fertilisation during a woman's reproductive lifespan.
Levels of AMH were measured from blood samples.
Researchers also took a medical history, including
details of smoking habits in mothers and daughters,
oral contraceptive use and body mass index (BMI).

After adjusting for various factors that could affect results
(e.g. smoking, contraceptive use, age and BMI), doctors
found that average AMH levels declined by 8.6% for grandmothers who began an early menopause,
6.8% for grandmothers who began menopause at a
normal (average) age, and 4.2% a year in women
with mothers who began a late menopause.

A similar pattern was seen for AFC, with annual declines
of 5.8%, 4.7% and 3.2% in the same groups respectively.

The study also found AMH and AFC levels were lower
(27.3% for AMH and 26.8% for AFC levels) in oral
contraceptive users compared with non-users.

AFC in women whose mothers smoked while pregnant
was an average of 11% lower, but there was no
significant effect on AMH levels.

Dr. Bentzen felt the effect of oral contraceptive use was
likely to be temporary and unlikely to influence the
long-term decline in ovarian follicles. However,
she feels clinicians and women should be aware of it
when considering a woman's reproductive life span
or any fertility treatments.


Dr. Bentzen: "We believe there is a need for longitudinal, large studies in which ovarian reserve parameters are measured repeatedly in the same individual before, during and after the use of oral contraceptives. Additionally, we need to explore the impact of dose-response and duration of hormonal contraception on markers of ovarian reserve."

In their paper, the authors write: "Clearly, our data does not explain whether maternal age at menopause is a direct predictor of age at menopause of the offspring, or the chance of pregnancy. Nevertheless, from a biological point of view, it may be reasonable to assume that a low ovarian reserve may have a long-term effect that will shorten the reproductive lifespan.

We therefore assume that markers such as 'maternal age at menopause' in combination with AMH or AFC, and chronological age may represent a more complete picture when evaluating the ovarian reserve of the individual. This assumption awaits longitudinal studies before it can be put to test."

[1] "Maternal menopause as a predictor of anti-Mullerian hormone level and antral follicle count in daughters during reproductive age", by J.G. Bentzen, J.L. Forman, E.C. Larsen, A. Pinborg, T.H. Johannsen, L. Shmidt, L. Friis-Hansen, and A. Nyboe Andersen. Human Reproduction. doi:10.1093/humrep/des356

Original article:http://www.eurekalert.org/pub_releases/2012-11/esoh-maa110512.php