Human reproduction in the context of Linebreeding

Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate is the average number of children born during an individual's lifetime. In medicine, fertility refers to the ability to have children, and infertility refers to difficulty in reproducing naturally. In general, infertility or subfertility in humans is defined as not being able to conceive a child after one year (or longer) of unprotected sex. The antithesis of fertility is infertility, while the antithesis of fecundity is sterility.

Love is an emotion involving strong attraction, affection, emotional attachment or concern for a person, animal, or thing. It is expressed in many forms, encompassing a range of strong and positive emotional and mental states, from the most sublime virtue, good habit, deepest interpersonal affection, to the simplest pleasure. An example of this range of meanings is that the love of a mother differs from the love of a spouse, which differs from the love of food.

Love is considered to be both positive and negative, with its virtue representing kindness, compassion, and affection—"the unselfish, loyal, and benevolent concern for the good of another"—and its vice representing a moral flaw akin to vanity, selfishness, amour-propre, and egotism. It may also describe compassionate and affectionate actions towards other humans, oneself, or animals. In its various forms, love acts as a major facilitator of interpersonal relationships, and owing to its central psychological importance, is one of the most common themes in the creative arts. Love has been postulated to be a function that keeps human beings together against menaces and to facilitate the continuation of the species.

The consummation of a marriage, or simply consummation, is the first officially credited act of sexual intercourse following marriage. In many traditions and statutes of civil or religious law, the definition usually refers to penile–vaginal penetration (i.e., heterosexual), and some religious doctrines hold an additional requirement prohibiting contraception. In this sense, "a marriage is consummated only if the conjugal act performed deposits semen in the vagina."

The religious, cultural, or legal significance of consummation may arise from theories of marriage as having the purpose of producing legally recognized descendants of both partners, or of providing sanction to their sexual acts together, or both, and its absence may amount to treating a marriage ceremony as falling short of completing the state of being married, or as creating a marriage which may later be repudiated. Thus, in some legal systems, a marriage may be annulled if it has not been consummated. Consummation is also relevant in the case of a common-law marriage. The historical importance of consummation has resulted in the development of various bedding rituals.

Penile–vaginal intercourse, or vaginal intercourse, is the insertion of an erect penis into a vagina. It is the primary form of copulation in mammals and a form of penetrative sexual intercourse in human sexuality. Synonyms are: vaginal sex, coitus (Latin: coitus per vaginam), (in elegant colloquial language) intimacy, or (poetic) lovemaking; some of which are used for other forms of intercourse as well. Cohabitation is a related term describing a living arrangement.

Various sex positions can be used. Following insertion, additional stimulation is often achieved through rhythmic pelvic thrusting or a gyration of the hips, among other techniques. The biological imperative is to achieve male ejaculation so that sperm can enter the female reproductive tract and fertilize the egg, thus beginning the next stage in human reproduction, pregnancy.

Sexual ethics (also known as sex ethics or sexual morality) is a branch of philosophy that considers the ethics or morality of human sexual behavior. Sexual ethics seeks to understand, evaluate, and critique interpersonal relationships and sexual activities from social, cultural, and philosophical perspectives. Some people consider aspects of human sexuality such as gender identification and sexual orientation, as well as consent, sexual relations and procreation, as giving rise to issues of sexual ethics.

Historically, the prevailing notions of what is regarded as sexually ethical have been linked to religious teachings and philosophy. More recently, the sexual revolution challenged traditional ethical codes, and the feminist movement has emphasized personal choice and consent in sexual activities, especially for women.

Human sexuality is the way people experience and express themselves sexually. This involves biological, psychological, physical, erotic, emotional, social, or spiritual feelings and behaviors. Because it is a broad term which has varied within different historical contexts, it lacks a precise definition. The biological and physical aspects of sexuality largely concern the human reproductive functions, including the human sexual response cycle.

Someone's sexual orientation is their pattern of sexual interest in the opposite and/or same sex. Physical and emotional aspects of sexuality include bonds between individuals that are expressed through profound feelings or physical manifestations of love, trust, and care. Social aspects deal with the effects of human society on one's sexuality, while spirituality concerns an individual's spiritual connection with others. Sexuality also affects and is affected by cultural, political, legal, philosophical, moral, ethical, and religious aspects of life.

The male reproductive system consists of a number of sex organs that play a role in the process of human reproduction. These organs are located on the outside of the body, and within the pelvis.

The main male sex organs are the penis and the scrotum, which contains the testicles that produce semen and sperm, which, as part of sexual intercourse, fertilize an ovum in the female's body; the fertilized ovum (zygote) develops into a fetus, which is later born as an infant. The corresponding system in females is the female reproductive system.

Reproductive rights are legal rights and freedoms relating to reproduction and reproductive health that vary amongst countries around the world. The World Health Organization defines reproductive rights:

Reproductive rights may include some or all of: right to abortion; birth control; freedom from coerced sterilization and contraception; the right to reproduce and start a family, the right to access good-quality reproductive healthcare; and the right to family planning in order to make free and informed reproductive choices. Reproductive rights may also include the right to receive education about sexually transmitted infections and other aspects of sexuality, right to menstrual health and protection from practices such as female genital mutilation (FGM). Protections from mistreatment during pregnancy, labor, delivery, and postpartum are also part of the reproductive rights framework, which calls into questions practices like shackling pregnant people in correctional facilities. Reproductive Rights are connected to broader social conditions and determinants, reproductive freedom requires not only legal rights but affordable healthcare, safe living environments, as well, as economic stability.

In human reproduction, a live birth occurs when a fetus exits a pregnant female showing any definite sign of life, such as voluntary movement, heartbeat or pulsation of the umbilical cord, for however brief a time, and regardless of whether the umbilical cord or placenta are intact. After the fetus leaves the womb it is called a neonate. It is a "live birth" whether the birth is vaginal or by caesarean section, and whether the neonate is ultimately viable.

The definition of the term "live birth" was created by the World Health Organization in 1950, and is chiefly used for public health and statistical purposes. However, the term "live birth" was in common use long before 1950.

The missionary position (or man-on-top position) is a sex position in which, generally, a woman lies on her back and spreads her legs and a man lies on top of her while they face each other and engage in vaginal intercourse. The position may also be used for other sexual activity, such as anal sex. It is commonly associated with heterosexual sexual activity, but is also used by same-sex couples. It may involve sexual penetration or non-penetrative sex (for example, intercrural sex), and its penile-vaginal aspect is an example of ventro-ventral (front-to-front) reproductive activity. Variations of the position allow varying degrees of clitoral stimulation, depth of penetration, participation on the part of the woman, and the likelihood and speed of orgasm.

The missionary position is the most common sex position, but it is not universally regarded as the most favoured one. The missionary position is often preferred by couples who enjoy the romantic aspects of ample skin-to-skin contact and opportunities to look into each other's eyes and kiss and caress each other. The position is also believed to be a good position for reproduction. During sexual activity, the missionary position allows the man to control the rhythm and depth of pelvic thrusting; it is also possible for the woman to thrust against him by moving her hips or pushing her feet against the bed, or squeeze him closer with her arms or legs. The position is not suitable for late stages of pregnancy, and is less desired when the woman wants to have greater control over the rhythm and depth of penetration during intercourse.

Sterilization (also spelled sterilisation) is any of several medical methods of permanent birth control that intentionally leaves a person unable to reproduce. Sterilization methods are available for both males and females. Although a non-surgical option for females ("Essure") was available until 2019, it is no longer an option. Sterilization procedures are intended to be permanent; reversal is generally difficult.

There are multiple ways of having sterilization done, but the two that are used most frequently are salpingectomy or tubal ligation for women and vasectomy for men. There are many different ways tubal sterilization can be accomplished. It is highly effective, like use of an IUD or arm implant, and in the United States, surgical complications are low. With that being said, tubal sterilization is still a method that involves surgery, so there is still a danger. Women who choose tubal sterilization have a higher risk of serious side effects than men who have a vasectomy do. Pregnancies after tubal sterilization can still occur, even many years after the procedure. Some recent studies have estimated that 3% of women become pregnant after tubal sterilization.It is not very likely, but if it does happen, there is a high risk of ectopic gestation. Tubal sterilization surgeries can be performed during a Cesarean section or shortly after a vaginal delivery mostly by mini-laparotomy. In some cases, sterilization can be reversed, but this can not be guaranteed. If you might want to become pregnant in the future, do not have this surgery.

Family planning is the consideration of the number of children a person wishes to have, including the choice to have no children, and the age at which they wish to have them. Factors that may influence family planning decisions include marital status, career or work considerations, or financial circumstances. If sexually active, family planning may involve the use of contraception and other techniques to control the timing of reproduction.

Other aspects of family planning—aside from contraception—include sex education, prevention and management of sexually transmitted infections, pre-conception counseling and management, and infertility management. Family planning, as defined by the United Nations and the World Health Organization, encompasses services leading up to conception. Abortion is another form of family planning, although it is not a primary one.

The human female reproductive system is made up of the internal and external sex organs that function in the reproduction of new offspring. The reproductive system is immature at birth and develops at puberty to be able to release matured ova from the ovaries, facilitate their fertilization, and create a protective environment for the developing fetus during pregnancy. The female reproductive tract is made of several connected internal sex organs—the vagina, uterus, and fallopian tubes—and is prone to infections. The vagina allows for sexual intercourse and childbirth, and is connected to the uterus at the cervix. The uterus (or womb) accommodates the embryo by developing the uterine lining.

The uterus also produces secretions which help the transit of sperm to the fallopian tubes, where sperm fertilize the ova. During the menstrual cycle, the ovaries release an ovum, which transits through the fallopian tube into the uterus. If an egg cell meets with sperm on its way to the uterus, a single sperm cell can enter and merge with it, creating a zygote. If no fertilization occurs, menstruation is the process by which the uterine lining is shed as blood, mucus, and tissue.

In mammals, the vulva (pl.: vulvas or vulvae) comprises mostly external, visible structures of the female genitalia leading into the interior of the female reproductive tract. For humans, it includes the mons pubis, labia majora, labia minora, clitoris, vestibule, urinary meatus, vaginal introitus, hymen, and openings of the vestibular glands (Bartholin's and Skene's). The folds of the outer and inner labia provide a double layer of protection for the vagina (which leads to the uterus). While the vagina is a separate part of the anatomy, colloquially the term has often been used synonymously with vulva. Pelvic floor muscles support the structures of the vulva. Other muscles of the urogenital triangle also give support.

Blood supply to the vulva comes from the three pudendal arteries. The internal pudendal veins give drainage. Afferent lymph vessels carry lymph away from the vulva to the inguinal lymph nodes. The nerves that supply the vulva are the pudendal nerve, perineal nerve, ilioinguinal nerve and their branches. Blood and nerve supply to the vulva contribute to the stages of sexual arousal that are helpful in the reproduction process.

Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and other consequences that may arise from expression of deleterious recessive traits resulting from incestuous sexual relationships and consanguinity.

Inbreeding results in homozygosity which can increase the chances of offspring being affected by recessive traits. In extreme cases, this usually leads to at least temporarily decreased biological fitness of a population (called inbreeding depression), which is its ability to survive and reproduce. An individual who inherits such deleterious traits is colloquially referred to as inbred. The avoidance of expression of such deleterious recessive alleles caused by inbreeding, via inbreeding avoidance mechanisms, is the main selective reason for outcrossing. Crossbreeding between populations sometimes has positive effects on fitness-related traits, but also sometimes leads to negative effects known as outbreeding depression. However, increased homozygosity increases the probability of fixing beneficial alleles and also slightly decreases the probability of fixing deleterious alleles in a population. Inbreeding can result in purging of deleterious alleles from a population through purifying selection.