科學(xué)家通過研究發(fā)現(xiàn)，婦女到30歲時(shí)就已經(jīng)消耗約90%的“卵子庫存”,。盡管三四十歲的婦女仍能排卵,，但是不僅其“卵子庫存”已經(jīng)所剩無幾,，而且卵子質(zhì)量下降,，不利于生出健康的嬰兒,。這一發(fā)現(xiàn)揭示了中年婦女年齡越大越難受孕的奧秘。
這一最新研究是由蘇格蘭圣安德魯斯大學(xué)和愛丁堡大學(xué)科研人員完成的,，發(fā)表在《公共科學(xué)圖書館·綜合》（PLoS ONE）上。所謂“卵子庫存”是指一名女性一生所能產(chǎn)生的潛在卵子總數(shù)量,。研究顯示,，女性的“卵子庫存”平均可達(dá)30萬，但是“卵子庫存”的減少速度大大超過先前估計(jì),。到30歲時(shí),，女性的“卵子庫存”平均還剩12%,，到40歲時(shí)，下降到3%,。
為了進(jìn)行這項(xiàng)研究,，科研人員收集了325名英、美和一些歐洲國家婦女的信息,。該研究的作者之一漢密斯-華萊士博士說：“研究表明,，婦女通常高估了自己的受孕幾率。”研究人員表示,，一些婦女錯(cuò)誤地認(rèn)為由于她們還能產(chǎn)生卵子,，就覺得自己的受孕能力還保持不變。該研究顯示,，事實(shí)上,，婦女的受孕能力會(huì)迅速下降。女性“卵子庫存”的個(gè)體差異巨大,。一些女性的“卵子庫存”數(shù)量超過200萬,，一些人只有不到3.5萬。
華萊士博士稱,，該項(xiàng)研究成果有助于預(yù)測(cè)哪些婦女會(huì)過早停經(jīng),，以及何時(shí)為卵巢癌患者冷凍卵子。該研究警告女性,，不要拖到年齡很大才準(zhǔn)備受孕,。女性超過35歲，受孕能力將明顯下降,，不過下降速度也因個(gè)體差異而不同,。一些醫(yī)生建議，定期對(duì)女性受孕能力進(jìn)行篩查,，正如宮頸癌篩查一樣,。（生物谷Bioon.com）
生物谷推薦原始出處：
PLoS ONE 5(1): e8772. doi:10.1371/journal.pone.0008772
Human Ovarian Reserve from Conception to the Menopause
W. Hamish B. Wallace1*, Thomas W. Kelsey2
1 Department of Reproductive and Developmental Sciences, Division of Child Life and Health, University of Edinburgh, Edinburgh, United Kingdom, 2 School of Computer Science, University of St Andrews, St Andrews, United Kingdom
The human ovary contains a fixed number of non-growing follicles (NGFs) established before birth that decline with increasing age culminating in the menopause at 50–51 years. The objective of this study is to model the age-related population of NGFs in the human ovary from conception to menopause. Data were taken from eight separate quantitative histological studies (n = 325) in which NGF populations at known ages from seven weeks post conception to 51 years (median 32 years) were calculated. The data set was fitted to 20 peak function models, with the results ranked by obtained correlation coefficient. The highest ranked model was chosen. Our model matches the log-adjusted NGF population from conception to menopause to a five-parameter asymmetric double Gaussian cumulative (ADC) curve ( r 2= 0.81). When restricted to ages up to 25 years, the ADC curve has r 2= 0.95. We estimate that for 95% of women by the age of 30 years only 12% of their maximum pre-birth NGF population is present and by the age of 40 years only 3% remains. Furthermore, we found that the rate of NGF recruitment towards maturation for most women increases from birth until approximately age 14 years then decreases towards the menopause. To our knowledge, this is the first model of ovarian reserve from conception to menopause. This model allows us to estimate the number of NGFs present in the ovary at any given age, suggests that 81% of the variance in NGF populations is due to age alone, and shows for the first time, to our knowledge, that the rate of NGF recruitment increases from birth to age 14 years then declines with age until menopause. An increased understanding of the dynamics of human ovarian reserve will provide a more scientific basis for fertility counselling for both healthy women and those who have survived gonadotoxic cancer treatments.
