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With Ham, Leeuwenhoek discovered animalcules in human semen in 1677, without theoretical interpretations. Discussions focused on the respective role of ovum and animalcules during two centuries with erroneous doctrines. Modern ideas on status and origin of animalcules are associated with the development of the cell theory. Animalcules became spermatozoa. In 1875, Hertwig observed that the head of spermatozoon becomes a pronucleus and combines with the female pronucleus, thus establishing the concept that fertilization is the conjugation of two cells. During the first half of 20th century, endocrinology and genetics influenced management of infertile couples. Cryopreservation, analyses of ultrastructural morphology improved knowledges of normal and abnormal male gametes. In Vitro Fertilization and more IntraCytoplasmic Sperm Injection opened new views on the role of spermatozoa in human generation. Genetics and procreation were more and more so linked that each perspective of further advances shocked ethical considerations as transgression of natural biology. The future of spermatozoon in human reproductive programs remains a mystery according to, for example, experimental development using stem cell cultures.
Although the potential applications of human embryonic stem cells and therapeutic cloning hold promise for the alleged medical benefits, these technologies have posed profound ethical issues because they necessitate the destruction of human embryos. A fundamental point in the issues is the concept of the moral status of human embryos. The Catholic Church has held that human life begins at the moment of conception and therefore, has defended the dignity, inviolable right to life and integrity of human embryos. The Catholic Church has opposed human embryonic stem cell research and any kind of human cloning because they are contrary to the dignity of procreation, of conjugal union and of human embryos. Moreover, these techniques have the risk of creating a sub-category of human beings that are destined basically for the convenience of others. In conclusion, science and technology can never be independent of the criterion of morality, since technology exists for man and must respect his finality.
A conflict of interest in scientific and medical research "between the investigation and correct treatment of illness ... and the financial objective of making a profit" was addressed in a papal message to an April 5-6 international conference on conflicts of interest in science and medicine sponsored by the Polish Academy of Sciences. The Vatican released the papal message April 11, which was addressed as a letter to Archbishop Jozef Kowalczyk, apostolic nuncio to Poland. The pope said that "there is a risk that science-based businesses and health care structures can be set up not in order to provide the best possible care for people in accordance with their human dignity but in order to maximize profits and increase business, with a predictable lowering in the quality of service of those unable to pay." For example, the pope said, the pharmaceutical industry, "driven by the pursuit of profit and catering to what could be called 'medicine of desires' ... has favored research which as already placed on the world market products contrary to the moral good, including products which are not respectful of procreation and even suppress human life already conceived." The pope expressed concern about how priorities are set for pharmaceutical research, as well as about cost-containment imperatives in hospital medical care. His letter was written in English. The text follows.
The spread of human immunodeficiency virus (HIV) infection in women of childbearing age has precipitated discussion of the procreative rights of this population. Ethical principles are cited to support both sides of the argument. Implications for nursing care include the need to (1) examine one's own opinion on the issue, (b) assess the context in which the patient is making her decision, (c) share detailed information, and (d) create a supportive environment.
"Humans' protracted maturation before childbearing is an extreme example of a general characteristic of higher organisms: a positive lower bound on ages of procreation. The pre-procreative span, much discussed for its evolutionary and social ramifications, has consequences also for the mathematics of population renewal.... This paper proves the presence of a pre-procreative span sufficient, in and of itself, to guarantee the existence condition for bifurcation for all models in one important class. The class includes the best-studied examples of age-specific systems with and without homeostatic feedback in purely discrete and in purely continuous formulations."
The matter of social sex selection is of universal interest. It is argued that it is so important that an insular response by the select committee on the subject must be replaced by one founded on an international human rights stance, in which light sex selection may only be seen as sexist per se.
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In practical life, unwanted pregnancy and prenatal human life are often irreconcilable and hence paradoxical. This paradox is aggravated by the fact that the doctor is aware of the human qualities associated with prenatal human life, as formulated today by researchers in biology and psychology: Any human being "in statu nascendi" is endowed with all the requisite human qualities right from the beginning. Seen from the anthropological point of view, the meaning of biological evolution is a development towards increasing spiritualisation and freedom, liberation and ability to change and to undergo transformation. Mental functions of the foetus are present from the eighth week of pregnancy. Human individuality begins with conception and procreation. The multifacetted meaning of the term "unwantedness" is examined. It is the doctor's burden to bear the antagonism between the sensitivity of prenatal human life on the one hand and the rigid wall of denial represented by unwantedness on the other, and to build a bridge of responsibility between the two.
Gonadotrophin releasing hormone (GnRH) agonists have had a profound impact on infertility treatment by in vitro fertilization and related procreation techniques. Its combination with human menopausal gonadotrophin (HMG) for superovulation has increased the success rate in patients with premature luteinizing hormone (LH) surges, a poor response, endometriosis or polycystic ovarian disease. Although most in vitro fertilization (IVF) centres routinely use GnRH agonists for reasons of a better planning of activities, its superiority as a first-line treatment over the more conventional regimes of clomiphene citrate (CC)/HMG or HMG alone is still debated. An increase of the number and maturity of recovered oocytes was reported by most groups, but an inverse relationship between the number of oocytes and embryo quality and pregnancy rate after cryopreservation has been frequently mentioned. The possible complications of the combined use of a GnRH agonist with HMG include the formation of ovarian 'follicle' cysts and ovarian hyperstimulation syndrome; luteal phase defects are also common. Routine luteal phase support with progesterone and oestradiol valerate or human chorionic gonadotrophin (HCG) is required. GnRH agonists have proved to be safe drugs, side-effects are minor and sporadic and the congenital malformation rate in GnRHa/HMG treatment is comparable to the spontaneous rates reported in national IVF registers.
New technologies, such as genetic screening, artificial insemination, in vitro fertilization, and pre-natal diagnosis, have given new meaning to human reproduction. Such innovations make clear that marriage, procreation, and the biological family are not the sole "natural" means of perpetuating the human race. One would have hoped that these inventions would eventually have raised in public regard the gay/lesbian family to the same level as heterosexuality and the biological family. Franklin shows, however, that the old heterosexual essentialism is preserved by government restricting the use of the new technologies to two-parent families consisting of both mother and father. What should have resulted in the erosion of heterosexual privilege has, instead, led to its reinforcement. Franklin draws a parallel with the AIDS epidemic which could have been the opportunity to spread knowledge and acceptance of varied forms of sexuality but has instead been used to shore up a traditional sexual morality and a renewed vilification of homosexuality.
This chapter describes general cryobiological principles and the different methods for cryopreservation of supernumerary human embryos obtained after several procedures for medically assisted procreation. Different factors that influence the performance of freezing and thawing of human embryos are reviewed: the data from international and national surveys of results, the cryopreservation procedures, the stages of embryonic development, the morphological appearance of the cryopreserved embryos, the numbers of embryos transferred, the storage times of embryos in liquid nitrogen, the ovarian stimulation protocols in the IVF cycle and the replacement cycles of cryopreserved embryos. Cryopreservation of embryos circumvents the difficult problem of synchrony between the ovarian cycles of donor and acceptor patients in an oocyte donation programme.
Most of the 1,400,000 men currently locked up in American prisons would have become tax-paying neighbors had they been switched in the hospital nursery and sent home with a mature, self-supporting, married couple. The parent with whom they did go home would in most instances not have been fit to adopt someone else's baby. It is argued that perhaps the only effective way to reduce crime and the other pathologies of the growing American underclass--apart from building still more prisons--would be to require from persons wishing to birth and rear a child of their own those same minimal criteria usually expected in adoptive parents. For evolutionary reasons, human beings are reluctant to interfere with the procreational rights of any person, no matter how immature, incompetent, or unsocialized he or she might be. In consequence, human beings tend not to think about the right of the child to a reasonable opportunity for life, liberty, and the pursuit of happiness.