[论文]试管婴儿简介

[论文]试管婴儿简介 试管婴儿 试管婴儿就是采用人工方法让卵细胞和精子在体外受精，并进行早期胚胎发育，然后移植到母体子宫内发育而诞生的婴儿。 不可否认试管婴儿技术是医学界的一个奇迹，这个奇迹给无法生育的人提供了一种繁衍后代的方法，更开辟了医学界的新领域。 今天体外受精已作为一项常规技术为许多不孕家庭带来了欢乐，至今世界上已有上百万试管婴儿诞生。然而30年前医学技术没有如此精湛，由于身体的种种原因，渴望做父母的夫妻一直不能如愿以偿。随着生物科学和医学技术的发展，对于这样的夫妇来说，生育可爱的宝宝已经不再是一个难题，他们可以借助试管婴儿技术，圆他们成为父母的梦～ 试管婴儿并不是真正在试管里长大的婴儿，而是一种医学技术，即体外受精 联合胚胎移植技术(in vitro fertilization and embryo transfer，IVF-ET)，是指分别将卵子与精子取出后，置于试管内使其受精，再将胚胎前体——受精卵移植回母体子宫内，并在子宫着床，发育成胎儿。试管婴儿就是采用人工方法让卵细胞和精子在体外受精，并进行早期胚胎发育，然后移植到母体子宫内发育而诞生的婴儿。所以“试管婴儿”可以简单地理解成由实验室的试管代替了输卵管的功能。 目前试管婴儿技术主要经历了三代，第一代技术是1978年爱德华兹和斯特普托实施成功的，主要解决女性受孕生子的问题。第二代技术是1992年由比利时Palermo医师及刘家恩博士首次在人体成功应用了卵浆内单精子注射技术。该技术不仅提高了试管婴儿成功率，而且使试管婴儿适应症扩大。随着分子生物学的发展，胚胎着床前遗传病诊断开始发展并用于临床。胚胎着床前遗传病诊断被称为第三代试管婴儿技术。第三代技术从生物遗传学的角度，帮助人类选择生育最健康的后代。 体外受精研究先驱——张民觉 精子获能的发现是人们最终实现体外受精的基础。20世纪50年代前，人们一直无法实现体外受精。直到1950年，美藉华人生物学家张民觉先生进行了开拓性研究，他成功揭开了精子获能现象的奥秘。张民觉认为以前人们未能成功实现体外受精是因为所用的精子是未经活化的原态精子。经过多次实验，张民觉找到了能使精子在体外活化的方法，终于在1959年成功完成了兔子体外受精的实验。张民觉在体外将黑色兔子的精子和卵子实现了融合，并将发育的胚胎植入一 只白色兔子子宫内，最终获得了一窝黑色幼崽，这是第一次真正意义上实现了哺乳动物体外授精。 此后，张民觉与同事继续改进和完善体外受精技术，摸索出一套使精子能在体外活化的办法，使得一些难度较大的中国田鼠、小鼠、大鼠体外受精都获得成功。1969年，他们还完成了人卵的体外受精，因为没有医生协助，未进行胚胎移植实验。在体外受精研究领域的成功使他成为该领域的研究先驱，动物实验结果为日后实现人的体外受精和试管婴儿的诞生打下了良好的基础。 体外受精之父——罗伯特•杰弗里•爱德华兹(Robert Geoffrey Edwards) 罗伯特•杰弗里•爱德华兹(Robert Geoffrey Edwards)出生于英国约克郡的一个小镇上，而后在曼彻斯特长大，并完成了高中教育。随着年龄的增加，爱德华兹逐渐对科学产生了浓厚的兴趣，尤其是遗传学，这推动了他一生在发育学领域的研究。爱德华兹研究的主要内容是卵子的体外受精，这需要从雌性小鼠体内收集一定数量的卵子，然而小鼠一般喜欢在午夜排卵，并且只有采集午夜卵子实验效果才最为理想，这使爱德华兹的工作常常持续到深夜。 在经过3年的艰苦工作后，爱德华兹决定改变这种工作状态。在借鉴他人工 作的基础上，爱德华兹与鲁思•福勒(Ruth Fowler)合作开发了一种新的方法，为雌性小鼠注射一定量的激素，这样不仅可控制小鼠排卵时间，还可以控制小鼠排卵的数量，该方法被称为福勒-爱德华兹法。这种方法避免了深夜取卵的麻烦，为研究生殖过程的早期问题奠定了坚实的技术基础。爱德华兹还发现了促使休眠卵子体外成熟的方法，解决了一些体外受精的关键步骤。然而在此之后爱德华兹的工作开展的并不顺利，直到1962年美籍华裔生殖生物学家张民觉成功完成体外受精才激发了爱德华兹的实验灵感。他用其他哺乳动物的卵子进行实验，证明了这种方法的可行性。 这些工作使爱德华兹于1965年决定研究人的卵子体外受精。 世界第一例试管婴儿的诞生 通过大量的研究工作，爱德华兹发现卵子的成熟需要37 小时而不是一般认为的12 小时。爱德华兹的研究还颠覆了生殖学领域的一个重大错误:传统观点认为精子必须进入女性生殖道内才具有受精能力，然而爱德华兹发现精子获能是在男性体内完成的，这意味着卵子体外受精可完全脱离母体而实现，这对于体外受精具有十分重要的意义。人类体外受精过程中还有很多科学难题，这些问题爱德华兹不得不一一解决，比如如何诱导妇女排卵，如何从卵巢中获取卵子，如何在体外培养卵子，如何在试管内使卵子和精子结合，最后再如何把受精卵植入母体子宫等等。在科学探索的道路上，不但需要努力，还需要幸运女神的眷顾。1967年，爱德华兹从杂志上了解到英国奥海姆一家小医院的妇产科医生帕特里克•斯特普托(Patrick Steptoe)发明了腹腔镜技术，可以在不损伤妇女的情况下观察女性生殖道。斯特普托是当时世界腹腔镜领域的顶级专家。爱德华兹立刻意识到腹腔镜在从妇女体内获取卵子方面具有巨大潜力，并立刻与斯特普托联系，并最 终达成了合作意向。1968年，爱德华兹与斯特普托正式合作，开始了人的体外受精研究。 在研究期间，他们遇到了从未想过的种种困难。尽管哺乳动物体外受精技术已经非常成熟，但在人体上的试验还有许多关键问题还没解决。爱德华兹和斯特普托经过18个月的努力才最终成功从不育妇女卵巢中获得有活性的卵子，并首次在体外实现了受精，而且令人兴奋的是1971年获得了有活性的人类胚胎，这是爱德华兹研究中一次重大突破。然而之后的研究又再次跌入失败的深渊，他们也曾经将胚胎植入母体并成功怀孕，但植入的是输卵管而不是子宫，因此不得不终止妊娠。经过一次一次的失败，终于在1976年，爱德华兹遇到了布朗夫妇，并成功说服他们接受体外受精试验。1977年11月9日，布朗太太开始排卵，第2天，斯特普托成功获得一枚卵子，并在体外实现了人工受精，2天后将发育出8个细胞的受精卵植入布朗太太的体内，幸运的是这次试验非常成功，布朗太太顺利怀孕，并且胎儿发育一切正常。1978年7月25日，激动人心的时刻终于到来了，世界上第一个试管婴儿——路易丝• 乔伊• 布朗(Louise Joy Brown)诞生了。小女孩的诞生宣告人类体外受精技术取得最终的胜利。 中国的试管婴儿之母——张丽珠 世界第一个试管婴儿出生时引起了社会的许多恐慌，但随后试管婴儿技术的快速发展却为整个医学界带来了一场医学革命。1980年澳大利亚，1981年美国等国家试管婴儿也陆续诞生。据文献报道，中国台湾于1985年4月、中国香港于1986年12月各有l例试管婴儿出生，但这些都是外国专家带着全套设备帮助实施完成的。 1988年3月10日上午8点56分，在北京医科大学第三临床医院，张丽珠教授主持研究的中国第一例试管婴儿成功出生，婴儿取名郑萌珠，体重7斤8两，身长52厘米。那一刻标志着中国生殖科学完成了一个新的突破，张丽珠教授用精湛的医术告诉世界中国可以独立完成世界尖端的体外生殖技术。至今我国已实施了10万多例体外受精联合胚胎移植手术，3万多名新生儿来到人间。 随着医学的进步，在体外受精联合胚胎移植的基础上，又发展了其他的助孕技术，如配子输卵管内移植、合子输卵管内移植、冷冻胚胎储存、赠卵体外受精移植等，进一步提高了妊娠成功率，解决了一些有特殊生育困难夫妇的生育问题。 试管婴儿的伦理问题 有人认为试管婴儿是把精子和卵子作为人体零配件工厂，是对生命的不尊重。但是有些人认为设计试管婴儿是符合人类伦理道德的，因为这是父母出于强烈的爱子之心，希望完成自己做父母的心愿。其实这仅仅是伦理问题的一个方面。随着技术的不断成熟，如今社会上出现了很多代孕母亲。代孕母亲的产生让试管婴儿有了两个名义上的母亲，一个是生物学意义的母亲，一个是提供子宫并孕育其成长的母亲。代孕现在已经被禁止，禁止的主要原因是担心代孕会变成一种商 业化行为。但不可否认禁止代孕确实也扼杀了一些夫妇为人父母的梦。最为深远的伦理道德影响可能是对试管婴儿身心造成的不良影响。由于一个供精者的精子可以给多个妇女进行体外受精，这就使人不得不担心由此可能导致的血亲婚配及遗传病的发生。 为了避免这种情况，各个国家都进行了相关规定。在中国已经设立了精子库联网，保存精子。但是当试管婴儿长大后得知自己的出身情况时，不知会对他们的身心造成何等的影响。这一切的猜测目前暂无数据证实。随着时间的推移，也许上述伦理问题会逐一暴露。 试管婴儿的安全性问题 试管婴儿不但存在伦理问题，其安全性也一直是争论的焦点。有研究明，试管婴儿出生时带有严重生理缺陷和体重不足的几率是普通婴儿的两倍。澳大利亚研究人员对837名通过第一代技术产下的婴儿、301名通过第二代技术产下的婴儿与4000名普通婴儿进行了比较，结果发现试管婴儿患有先天性缺陷的比例高于普通婴儿。美国疾病控制预防中心的流行病专家发现，试管婴儿存在先天缺陷的可能性是普通婴儿的两倍到四倍:试管婴儿发生先天心脏缺陷的可能性是正常婴儿的两倍到三倍、天生唇裂的风险是普通婴儿的两倍、先天肠胃缺陷的风险是普通婴儿的四倍。此外，美国亚特兰大疾病预防与控制中心研究人员对美国1996年到1997年间出生的42463名试管婴儿与1997年间出生的430万普通婴儿进行了对比，发现试管婴儿出生时体重不足的情况是普通婴儿的2.6倍，且出生时体重不足的婴儿死亡率高于普通婴儿。虽然试管婴儿在1997年前出生的10岁以下婴儿中只占0.6%，但是在那期间出生的体重不足的婴儿中试管婴儿却占了7.8%。 试管婴儿的安全性问题无疑给希望通过试管婴儿圆梦的夫妻泼了一盆冷水。迄今为止，试管婴儿的弊端还不止于此，任何打算接受体外受精的夫妇都要认真地权衡利弊，即使试管婴儿经历了三代技术的不断改进，但依旧无法替代人类自身的生产过程。 试管婴儿的未来之路 不可否认试管婴儿技术是医学界的一个奇迹，这个奇迹给无法生育的人提供了一种繁衍后代的方法，更开辟了医学界的新领域。相信在不远的将来会出现更先进的试管婴儿技术造福于人类。 (作者:马驰) Test tube baby IVF is the use of artificial methods allow the egg and sperm in vitro fertilization, and early embryonic development, and then transplanted into the womb growth and the birth of the baby. Undeniable test-tube baby technology is one of the medical profession miracle, the miracle to infertile people provides a reproduction method, more open up new areas of the medical profession. Today in vitro fertilization has as a conventional technique for many infertile family brought joy, so far the world has millions of test-tube baby was born. However 30 years ago medical technology is not so excellent, due to health reasons, eager parents never have got one's wish. The biological science and the development of medical technology, for such couples, fertility cute baby is no longer a problem, they can use the technology of test tube baby, they become parents dream circle! IVF is not really in the test tube babies grew up, but a medical technology, namely the in vitro fertilization embryo transfer technology joint (in vitro fertilization and embryo transfer, IVF-ET ), refers to the egg and sperm were removed, placed in test tubes to the essence, the embryonic precursor -- transplantation of fertilized egg back the womb, and in the uterus during implantation, develops into a fetus. IVF is the use of artificial methods allow the egg and sperm in vitro fertilization, and early embryonic development, and then transplanted into the womb growth and the birth of the baby. So" IVF" can be simply understood by the laboratory test tube instead of the tubal function. The test-tube baby technology mainly experienced three generations, the first generation technology is the 1978Edwards and Steptoe successfully carried out, mainly solving the problems of women to conceive a child. Second generation technology is 1992by the Belgian Dr. Palermo and Dr. Liu Jiaen first in human application of intracytoplasmic sperm injection. The technology can not only improve IVF success rates, and enable IVF indications expand. With the development of molecular biology, embryonic preimplantation genetic diagnosis for clinical development and start. Embryo preimplantation genetic diagnosis is called the third generation test-tube baby technology. Third generation technology from biological genetics, to help people choose the most healthy offspring birth. Study on in vitro fertilization pioneer -- Zhang Minjue The found of sperm capacitation is that people ultimately achieved by in vitro fertilization based. Before the nineteen fifties, it has been impossible to achieve in vitro fertilization. Until 1950, the United States by Chinese biologist Sir Zhang Minjue made a pioneering study, he successfully opened the mystery of sperm capacitation phenomenon. Zhang Minjue thinks people had failed to achieve in vitro fertilization is because the sperm is not activated by the original state of sperm. After many experiments, Zhang Minjue found that sperm in vitro activation method, finally in1959 the successful completion of the rabbit in vitro fertilization experiment. In vitro Zhang Minjue black rabbit sperm and egg fusion was achieved, and the development of the embryo implantation of a white rabbit uterus, finally obtained a nest of black pups, this is the first time to achieve a true sense of mammalian in vitro fertilization. Thereafter, Zhang Minjue and colleagues continue to improve and perfect the in vitro fertilization technology, and explore a set of the sperm in vitro activation approach, makes some difficult Chinese hamsters, mice, rats in vitro fertilization success. In 1969, they also completed the human oocyte in vitro fertilization, because there is no physician assistance, without embryo transplantation. In vitro fertilization research success made him a pioneer in the field of animal experimental results for the future, realize human in vitro fertilization and the test tube babies born to lay a good foundation. In vitro fertilization father -- Robert Geoffrey Edwards ( Robert Geoffrey Edwards ) Robert Geoffrey Edwards ( Robert Geoffrey Edwards ) was born in a small town in Yorkshire, and grew up in Manchester, and completed a high school education. Increase with age, Edwards became very interested in science, especially the genetics, which promoted his life in developmental research. Edwards focuses on the in vitro fertilization of eggs from female mice, the need to collect a certain number of eggs, but the mouse love in the midnight ovulation, and only collection midnight egg experimental effect is ideal, which makes Edwards's work often continued late into the night. After 3 years of hard work, Edwards decided to change the working state. In draw lessons from others on the basis of the work, Edwards and Ruth Fowler ( Ruth Fowler ) cooperation has developed a new method, for female mice injected with a certain amount of hormones, so that it not only can control the mouse ovulation time, also can control the mouse ovulation number, the method is called the Fowler - Edwards Fa. This method avoids the night of oocyte trouble, for the study of the reproductive process of early problem laid a solid technical foundation. Edwards also discovered the cause of dormancy ovum maturation in vitro method, solved some key steps in vitro fertilization. But then Edwards's work is not smooth, until the 1962American reproductive biologist Zhang Minjue completed successfully in vitro fertilization to inspire Edwards's experiment inspired. He used other mammalian egg experiment, proved the feasibility of this method. These work made Edwards decided in 1965 to study human eggs in vitro fertilization. The world's first IVF baby Through a lot of research work, Edwards found that the ovum maturation takes 37hours and is not generally considered the12 hours. Edwards's research has overturned the reproductive sciences a major mistake: the traditional view is that the sperm into the female reproductive tract must only with the fertilization ability of sperm capacitation, however Edwards found in the male body is completed, this means egg IVF can be completely divorced from the mother and the implementation, this is very important for in vitro fertilization meaning of. Human in vitro fertilization process there are many scientific problems, these problems have to solve the Edwards one one, such as how to induce ovulation in women, how to obtain the egg from the ovary, how in vitro oocytes in vitro, how to make the egg and sperm binding, and finally how to fertilized egg implantation into the mother's womb. On the scientific exploration road, not only need to work, also need to be unlucky. On 1967, Edwards from the journal to learn English in Oldham in a small hospital obstetrician Patrick Steptoe ( Patrick Steptoe ) invented the laparoscopic technique, can not damage the women observed in female genital tract. Steptoe was the top experts in the field of world laparoscopic. Edwards immediately aware of laparoscopy in women from obtaining ova has enormous potential, and immediately and Steptoe contact, and eventually reached the cooperation intention. In 1968, Edwards and Steptoe formal cooperation, began the study of in vitro fertilization. During the study period, they had never thought of all sorts of difficulties. Although mammalian in vitro fertilization technology is already very mature, but in humans and many key does not solve the problem. Edwards and Steptoe after 18 months of hard work finally success from infertile women get active ovarian eggs, and for the first time in in vitro fertilization is realized, and the excitement is obtained in 1971, have activity of human embryos, it is Edwards a major breakthrough in the study of. However after the study once again fell into the abyss of failure, they also have the embryo will implant matrix and successful pregnancy, but implantation is tubal rather than the uterus, so had to terminate the pregnancy. After the failure of the first time, finally in 1976, Edwards met Brown, and successfully persuaded them to undergo in vitro fertilization experiment. In November 9, 1977, Brown began to ovulation, second days, Steptoe successfully obtained an egg, and achieved in vitro insemination,2 days later will develop8cells of the fertilized egg implantation of Mrs. Brown's body, fortunately this experiment is a great success, Mrs. Brown uneventful pregnancies, and fetal development of all normal. In July 25, 1978, the exciting moment finally arrived, the world's first IVF baby -- Louise Joey Brown ( born Louise Joy Brown ). The little girl declared the birth of human in vitro fertilization technology to achieve the final victory. The Chinese test tube baby mother -- Zhang Lizhu The world's first IVF birth has aroused many panic, but subsequent IVF technology fast development but for the entire medical community has brought a revolution in medicine. In 19801981the United States and other countries Australia, IVF is born in succession. According to reports in the literature, Chinese Taiwan in 1985April, China Hongkong in 1986December each l cases IVF birth, but these are foreign experts with a full set of equipment to help the implementation of the completion of the. Eight fifty-six in the morning of March 10, 1988, at the Beijing Medical University Third Hospital, Professor Zhang Lizhu led the research of China 's first test-tube baby, successful birth, baby Zheng Mengzhu, weight 7 kg8two, height 52cm. That moment marked the Chinese reproductive sciences completed a new breakthrough, Professor Zhang Lizhu with masterly skill told the world that China can independently complete the sophisticated world of in vitro reproductive technology. Since China has carried out more than 10cases in vitro fertilization and embryo transplantation operation, more than 30000 newborns came to earth. With advances in medicine, in vitro fertilization and embryo transfer based on, but also the development of other assisted reproductive technologies, such as gamete intrafallopian transfer, zygote intrafallopian transfer, embryo freezing storage for oocyte donation, in vitro fertilization and embryo transfer and so on, to further improve the success rate of pregnancy, to solve some special reproductive difficulties couple fertility problems. IVF ethics problems Some people think that IVF is the sperm and eggs as human spare parts factory, is on life do not respect. But some people think design IVF is consistent with human ethics, because it is the parents out of the strong son of the heart, I hope to finish their parents wish. In fact, this is only one aspect of the problem of ethics. As technology continues to mature, today the community appeared a lot of surrogate mother. Surrogate mother the IVF has two nominal mother, one is the biological significance of the mother, one is to provide uterine growth and pregnant mother. Surrogacy is now banned, ban is the main reason to worry about surrogacy would become a commercial behavior. But undeniable forbidding surrogate did kill some couples parenting dream. The most profound ethical effect may be to IVF and adverse effects. As a result of a donor 's sperm can give a plurality of women undergoing in vitro fertilization, which makes people have to worry about which may lead to the incest and genetic diseases. To avoid this, each country has the relevant provisions. In China has established a sperm bank networking, preservation of sperm archives. But when the test tube babies grow up after their own birth circumstances, not on their mental and physical cause what effect. All of this speculation is currently no data to confirm. With the passage of time, perhaps in these ethical issues will by exposure. Test tube baby safety problems Test tube babies not only the existence of ethical problems, its safety has also been a debate. Studies have shown that, test-tube babies born with severe physical impairments and underweight probability is two times the ordinary baby. Australian researchers in 837by the first generation technology births,301through second generations of technological births and4000 normal infants were compared, it was found in an infant with a congenital defect ratio higher than ordinary baby. The United States Centers for Disease Control and prevention of the epidemic experts found that the presence of congenital defects, IVF is the possibility of ordinary baby two times to four times the occurrence of congenital heart defects: IVF is the possibility of normal infants in two times to three times, the risk is common in infants born with cleft lip two times, congenital gastrointestinal defects is a common risk infants four times. In addition, the United States of America Atlanta Center for Disease Control and prevention researchers to the United States from 1996 to 1997, born42463test-tube babies born between 4300000and1997normal infants were compared, found IVF birth weight is2.6 times the ordinary infant, low birth weight and infant mortality was higher than that of normal infants. Although the test tube babies born before 199710infants aged only 0.6%, but during that time the birth weight infants IVF has accounted for 7.8%. Test tube baby safety problem will undoubtedly bring a hope through IVF couples poured a pot of cold water. So far, IVF malpractice also more than that, any intention to accept IVF couples must carefully weigh the advantages and disadvantages of test-tube baby, even after three generations of technology continues to improve, but still cannot replace human own production process. Test tube baby of the road to the future