Lexicon
The following definitions are those of Mons. Suaudeau. Through their accuracy and precision they are useful in reading the modules in this seminar, but they can also serve as reference in any bioethical training activity.
Abortion: expulsion from the uterus of an embryo or foetus, causing its death, either as a result of a natural, involuntary process (spontaneous abortion, ‘miscarriage’) or of a voluntary, artificial process (induced, elective abortion).
Blastocyst: from the Greek blastos (germ, bud) and kustis (“cyst”, cavity). The blastocyst is the embryo on the fifth day after fertilization, at the precise moment of its implantation in the uterine endometrium. Comprising 64 to 128 cells, it is formed after the morula and is characterized by the apparition, within its cells, of a fluid-filled cavity, the blastocoel, that separates an inner cell mass, which will later be the embryoblast, from an external layer of cells called the trophoblast, through which the embryo will be attached to the uterine endometrium.
Contraception: the range of means used to prevent conception, in a way that is temporary and reversible. Contraception intentionally places an objective obstacle in the way of fertilization. A distinction must be drawn between contraception and periodic abstinence, in which a couple places no obstacle in the way of fertilization, using only the naturally infertile periods in the menstrual cycle. It is also differs from sterilization, which places a permanent, irreversible (or reversible only with difficulty) obstacle in the way of fertilization.
Contraceptive mentality: refusal of the procreating capacity of the sexual act. This leads to preventing as fully as possible the natural processes that bring about fertilization. The contraceptive mentality separates the two dimensions of the sexual act, the unitive and the procreative, and goes counter the responsible exercise of fatherhood and motherhood realized in the full truth of the conjugal act. The contraceptive mentality also leads to refusing responsibility in case of contraceptive failure, which easily leads to falling into the temptation to resort to abortion when an unwanted life is conceived. Certainly, from the moral point of view, contraception and abortion are specifically different evils but they “are often closely connected, as fruits of the same tree” (Evangelium Vitae encyclical, nr 13).
Contragestive techniques: techniques that cause the elimination of the embryo after its implantation in the uterus. They resort to the administration of mifepristone (RU 486, Mifegyne) followed by a prostaglandin (Misoprostol oral, Cytotec) or methotrexate. These techniques cause a so-called ‘medical’ abortion when they are used at the beginning of a pregnancy, in the first 49 days of pregnancy in the case of Mosprostol and Cytotec, and in the first 56 days in the case of methotrexate (less used because it leads to more side accidents).
Embryo: initial state of the human being, from the moment of fertilization until the 60th day of pregnancy.
Embryoblast or inner cell mass: mass of cells inside the primordial embryo that will eventually give rise to the definitive structures of the foetus.
Emergency contraception (or post-coital contraception, or pre-implantatory contraception, or ‘morning-after pill’): the range of means that can be used in the hours (up to 72 hours) after a potentially fertilizing sexual intercourse, with the aim of preventing the development of a pregnancy.
Endometrium: mucus lining of the uterus. During ovulation, this mucus becomes thicker, providing a hospitable environment for a blastocyst (fertilized oocyte), allowing it to nidate and develop. At the end of the menstrual cycle, if no blastocyst has adhered to the mucus lining, it will be shed (menstruation).
Estrogens: female sex hormones, produced by developing follicles in the ovaries, then by the corpus luteum and the placenta once a pregnancy has started. From a biochemical perspective, they are steroids that derive from androgens. They come into play during puberty promoting the development of secondary sexual characteristics (such as breasts) and are also involved in regulating the menstrual cycle. The production of estrogens by the ovary starts increasing after menstruation, reaches its peak the day before ovulation (follicular phase of the cycle) and plummets during ovulation (14th day of the cycle), increasing again, more discretely, during the luteal phase, while secretion of progesterone (produced by the corpus luteum in the ovary) rises sharply. If fertilization does not occur, the secretion of estrogens and progesterone drops, reaching its lowest level on the 28th day of the cycle (menses). The three naturally occurring estrogens are estradiol, estriol and estrone. Synthetic estrogens are created in a laboratory and have a chemical structure similar to that of naturally occurring estrogens. They are used to correct an insufficient secretion (in case of female hypo-fertility) and after menopause in order to prevent osteoporosis. Combined with progestogens, these synthetic estrogens block ovulation and are used for contraceptive purposes.
Egg: common and imprecise term used to indicate the oocyte, both when it has just been released by the ovary and when it is already fertilized in the tube. The terms oocyte or ovum, and embryo respectively are more accurate.
Family planning: series of means and methods that make it possible for a couple to adjust the number and spacing of children in their family to its material and educational possibilities. A difference should be made between parents’ family planning as the practical way of a responsible father and mother, and family planning as the associative movement that promotes a sexuality that is “liberated” from its procreative component by means of the different contraceptive methods and, eventually, by abortion.
Fertilization: formation of an embryo through the successful penetration of a male gamete (sperm cell) and a female gamete (oocyte or ovum) followed by the fusion of its components, cytoplasm and nucleus (“pronuclei”).
Fertilized egg: it is the global product of fertilization, from the formation of the initial embryo (the “zygote” produced by the successful fertilization of the oocyte) until it implants in the uterine endometrium. This implantation is also known as “nidation”, when the fertilized egg is composed of an inner cell mass (embryoblast, which will subsequently form the embryo) and the trophoblast (the outer layer of the egg, which will later form the placenta), separated by the blastocoele (a fluid-filled cavity that will later become the amniotic sac). During this period of about five to six days, the embryo travels down the Fallopian tube, from the infundibulum to the isthmus, emerging in the uterine cavity at the ostium, while organizing itself in degrees of increasing complexity (cleavage, epigenetic reprogramming of the zygote’s genome, activation of development cells, genetic transmission from the mother to the zygote, loss of totipotency, compaction, formation of tight junctions and gap junctions), resulting –through cell division, with no growth– in the “morula” (8-16 cells called blastomeres, totipotent) (on the 4th day, cells polarize into peripheral cells and central cells). The morula then becomes a blastocyst (64-128 cells) and a central cavity called blastocoel forms. During the embryo’s implantation (“nidation”), it is the fertilized egg that imbeds in the uterine mucus, through the trophoblast, not the embryo itself, which individualizes at the centre of this fertilized egg in the shape of an embryoblast (or inner cell mass).
Fœtus: state of human being from the 60th day of pregnancy until birth.
Human being: living entity with a human phenotype (intellectual and physical characteristics) and genotype (DNA sequence specific to each species). Through its phenotype, the human being is biologically-speaking a human individual with a human organism that continually changes shape and substance throughout its life cycle, without changing identity.
Interceptive techniques: techniques that prevent the implantation of the embryo in the uterus and thereby provoke its expulsion and death. Although they are presented as being contraceptive, they are in fact abortive. The following are interceptive techniques: the ‘morning-after pill’ (also called emergency contraception), which can either be a Yuzpe Regimen or a high dose of levonorgestrel (“Norlevo”); intra-uterine devices (Norlevo); mifepristone, when taken during ovulation or shortly after.
Natural methods: a woman’s self-acknowledgement of her menstrual cycle, making it possible for her to space births or, on the contrary, to facilitate them by making the most of the natural alternation of her fertile and infertile periods.
Oocyte or ovum: a cell released by a mature Graaf Follicle in the ovary (ovulation) into the Fallopian tube, where it can either be fertilized by a sperm cell or degenerate and be eliminated. The oocyte is the female gamete, whereas sperm is the male gamete. The oocyte contains half of the future zygote’s genetic baggage.
Pearl Index: index that makes it possible to measure the effectiveness of contraceptive techniques by establishing the number of pregnancies observed in the course of one year in 100 women using a given technique, taking into account the number of months (or cycles) of usage. The lower the index, the more “efficient” the contraceptive or abortive technique is.
Periodic abstinence: a couple’s refraining from sexual intercourse during certain parts of the menstrual cycle (repeated every cycle in the same manner) with the aim of either spacing births (the couple abstains from sexual intercourse during the fertile period of the woman’s cycle) or, on the contrary, achieving a pregnancy (in this case, abstinence should take place during the infertile period of the cycle). The fertile part of the menstrual cycle goes from four days before ovulation to the day after ovulation. Ovulation takes place 14 days after the period. It is marked in particular by a transformation of the cervical mucus, which becomes more abundant, transparent and fluid. Periodic abstinence goes hand in hand with a woman’s knowledge of her fertility and with dialogue between husband and wife on the practice of sexual relations in their couple.
Pre-embryo: term that designates the human embryo before its implantation in the uterus. It is not a scientific term, but rather a semantic manoeuvre designed to disqualify the early embryo by denying its value as a human being. It is not used in scientific treatises and publications, but can be found in political or polemic texts and even in some textbooks.
Primitive streak: first axis that forms during the early stages of embryonic development, establishing bilateral symmetry.
Progestogens: synthetic compound with a biochemical composition close to that of the naturally occurring hormone (progesterone), and used for therapeutic or contraceptive purposes (for example, levonorgestrel, the “morning-after” pill). In order to be considered a progestogen, a molecule must be able to simulate the luteal phase (secretionary differentiation of the mucus membrane in the uterus prepared by estrogens) as well as a pro gestational effect (maintaining pregnancy despite the absence of corpus luteum in the ovary). Progestogens have little or no inhibitive effect on ovulation. Their contraceptive effect is carried out by thickening the cervical mucus and preventing the cell and vascular development of the uterine endometrium that is necessary to the implantation of the embryo (interceptive, anti-implantation, abortive effect).
Sterilization: the act of making an organism infertile. It is the intentional and conscious suppression of fertility in the subject in question, without affecting other sexual or endocrine functions (this differentiates it from castration). It can be applied to a man or a woman. Sterilization includes all methods used to make a living being, male or female, permanently unable to reproduce. Until recently, the techniques used to make a person infertile led to permanent, almost irreversible, sterility. Today, the development of appropriate surgical techniques sometimes (but not always) makes it possible to restore fertility after sterilization has been carried out by tubal ligation (in women) or deferentectomy/vasectomy (in men). Other techniques have been recently developed, such as the temporary occlusion of the Fallopian tubes (Essure), which supposedly allow restoring fertility on demand by removing the inserts that obstruct the tubes, provided they have not caused permanent alterations in the tubes.
Trophoblast: outer layer of cells of the embryo, through which it attaches itself to the uterus wall, allowing it to feed on uterine fluids and to develop the placenta.
Zygote: the result of fertilization, it is the initial form of an embryo, the first stage of human life, at the very beginning of the life cycle. The zygote is a single cell with two nuclei (the pronuclei), and it stays as such for 20-25 hours before the first cleavage segmentation divides it into two blastomeres and it becomes an embryo with two cells.