Editing Multiple birth (section)

==Terminology==
[[File:TwinsTwins.JPG|right|thumb|Fraternal twins at two weeks old. The technical term for "fraternal" is "dizygotic" (twins) or "polyzygotic" (triplets or higher order).]]
[[File:Being a twin means you always have a pillow or blanket handy.jpg|thumb|upright=1.2|Fraternal twin sisters taking a nap. Nonidentical twins, the most common kind of multiple birth among humans, occur in about{{nbsp}}1{{nbsp}}out of every 80 pregnancies.]]
Terms used for the number of offspring in a multiple birth, where a number higher than three ends with the suffix ''-uplet'':
*two offspring – [[twins]]
*three offspring – triplets
*four offspring – quadruplets
*five offspring – quintuplets
*six offspring – sextuplets
*seven offspring – septuplets
*eight offspring – octuplets
*nine offspring – nonuplets

Terms used for multiple births or the genetic relationships of their offspring are based on the [[zygosity]] of the pregnancy:
* Monozygotic – multiple (typically two) fetuses produced by the splitting of a single [[zygote]]
* Polyzygotic – multiple fetuses produced by two or more zygotes:
** Dizygotic – multiple (typically two) fetuses produced by two zygotes
** Trizygotic – three or more fetuses produced by three zygotes
** Sesquizygotic – an egg which is fertilized by 2 sperms, which produce 2 fetuses

Multiple pregnancies are also classified by how the fetuses are surrounded by one or more [[placenta]]s ([[Twin#Chorionicity|chorionicity]]) and [[amniotic sac]]s ([[Twin#Chorionicity|amnionicity]]).<ref>{{Cite web |date=September 2011 |title=Glossary: Multiple pregnancy: antenatal care for twin and triplet pregnancies |url=https://www.nice.org.uk/guidance/cg129/chapter/appendix-e-definitions-of-key-terms |publisher=NICE}}</ref>