Multiple births

culmination of one multiple pregnancy, wherein the mother delivers two or more offspring; applicable to placental species

animal offspring

Superfecundation is the fertilization of two or more ova from the same menstrual cycle by sperm from the same or different males, whether through separate acts of intercourse or during a single sexual encounter with multiple males. This can result in twin babies that have different biological fathers.

St. Quiteria was a fifth-century saint and virgin martyr about whom little is certain except her name, the date, place, and cause of her death, and existence of her cult. She is listed under the date of 22 May in the Roman Martyrology. She is one of the patron saints of Toledo, Spain. Accounts of her life include refusal to marry, protection for the vulnerable, and waging a guerilla war against the Roman Empire.

Superfetation (also spelled superfoetation – see fetus) is the simultaneous occurrence of more than one stage of developing offspring in the same animal. This phenomenon is extremely rare in humans, with only 10 confirmed cases.

Cryptophasia is the phenomenon of a language developed by twins (identical or fraternal) that only the two children can understand. The word has its roots from the Greek crypto-, meaning secret, and -phasia, meaning speech. Most linguists associate cryptophasia with idioglossia, which is any language used by only one, or very few, people. Cryptophasia differs from idioglossia on including mirrored actions like twin-walk and identical mannerisms.

thumb|The Giacomo and Giovanni Battista Tocci|Tocci Brothers, c. 1881

mother of octuplets

Russian peasant, father of 87 children

six male and two female children conceived via in vitro fertilization

prolific mother and wife of Feodor Vassilyev (1707–1782)