multiple pregnancy
pregnancy in which two or more fetuses exist simultaneously; it may be monovular (resulting from the fertilization of a single oocyte) or polyovular (resulting from the fertilization of more than one oocyte). When more than two fetuses coexist, they may come from one zygote or be the result of combined monovular and polyovular twinning. Called also multiple gestation.
Medical dictionary.
2011.