Human reproduction is any form of sexual reproduction resulting in the conception of a child, typically involving sexual intercourse between a man and a woman. During sexual intercourse, the interaction between the male and female reproductive systems results in fertilization of the woman's ovum by the man's sperm, which after a gestation period is followed by childbirth. The fertilization of the ovum may nowadays be achieved by artificial insemination methods, which do not involve sexual intercourse.
Birth control, also known as contraception and fertility control, are methods or devices used to prevent pregnancy. Planning, provision and use of birth control is called family planning. Safe sex, such as the use of male or female condoms, can also help prevent sexually transmitted infections. Birth control methods have been used since ancient times, but effective and safe methods only became available in the 20th century. Some cultures deliberately limit access to birth control because they consider it to be morally or politically undesirable.
The most effective methods of birth control are sterilization by means of vasectomy in males (99.85% success rate) and tubal ligation in females (99.5% success rate), intrauterine devices (IUDs) and implantable contraceptives. This is followed by a number of hormonal contraceptives including oral pills, patches, vaginal rings, and injections. Less effective methods include barriers such as condoms, diaphragms and contraceptive sponge and fertility awareness methods. The least effective methods are spermicides and withdrawal by the male before ejaculation. Sterilization, while highly effective, is not usually reversible; all other methods are reversible, most immediately upon stopping them. Emergency contraceptives can prevent pregnancy in the few days after unprotected sex. Some regard sexual abstinence as birth control, but abstinence-only sex education may increase teen pregnancies when offered without contraceptive education.
Morning sickness, also called nausea gravidarum, nausea, vomiting of pregnancy (emesis gravidarum or NVP), or pregnancy sickness is a pregnancy discomfort that affects more than half of all pregnant women. Sometimes symptoms are present in the early hours of the morning and reduce as the day progresses. However, in spite of its common name, it can occur at any time of the day. For most women it may stop around the 12th week of pregnancy.
Related to increased estrogen levels, a similar form of nausea is also seen in some women who use hormonal contraception or hormone replacement therapy. The nausea can be mild or induce actual vomiting, however, not severe enough to cause metabolic derangement. In more severe cases, vomiting may cause dehydration, weight loss, alkalosis and hypokalemia. This condition is known as hyperemesis gravidarum and occurs in about 1% of all pregnancies. Nausea and vomiting can be one of the first signs of pregnancy and usually begins around the 6th week of pregnancy (counting gestational age from 14 days before conception).
Hyperemesis gravidarum (HG) is a complication of pregnancy characterized by intractable nausea, vomiting, and dehydration and is estimated to affect 0.5–2.0% of pregnant women. Malnutrition and other serious complications, such as fluid or electrolyte imbalances, may result.
Hyperemesis is considered a rare complication of pregnancy, but because nausea and vomiting during pregnancy exist on a spectrum, it is often difficult to distinguish this condition from the more common form of nausea and vomiting experienced during pregnancy known as morning sickness.
Entertainment is a form of activity that holds the attention and interest of an audience, or gives pleasure and delight. It can be an idea or a task, but is more likely to be one of the activities or events that have developed over thousands of years specifically for the purpose of keeping an audience's attention. Although people's attention is held by different things, because individuals have different preferences in entertainment, most forms are recognisable and familiar. Storytelling, music, drama, dance, and different kinds of performance exist in all cultures, were supported in royal courts, developed into sophisticated forms and over time became available to all citizens. The process has been accelerated in modern times by an entertainment industry which records and sells entertainment products. Entertainment evolves and can be adapted to suit any scale, ranging from an individual who chooses a private entertainment from a now enormous array of pre-recorded products; to a banquet adapted for two; to any size or type of party, with appropriate music and dance; to performances intended for thousands; and even for a global audience.
The experience of being entertained has come to be strongly associated with amusement, so that one common understanding of the idea is fun and laughter, although many entertainments have a serious purpose. This may be the case in the various forms of ceremony, celebration, religious festival, or satire for example. Hence, there is the possibility that what appears as entertainment may also be a means of achieving insight or intellectual growth.