a pregnancy in which two embryos develop in the uterus at the same time; dizygotic twins are derived from two zygotes that develop from two fertilized oocytes; monozygotic twins are derived from one zygote that develops from a single fertilized oocyte; the zygote divides at an early stage of development to form two embryos.
Farlex Partner Medical Dictionary © Farlex 2012
twin pregnancyA term of art for the extremely rare coexistence of a normal intrauterine pregnancy and gestational trophoblastic disease (GTD). Because management is difficult, such cases should be handled in tertiary care centres, especially if the woman elects to carry the foetus to term. Up to 40% deliver a healthy baby despite the known risks of complications, including pulmonary embolism and pre-eclampsia. Women have little risk of developing persistent GTD after a “twin pregnancy”.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.