Friday, 6 June 2014


The human female usually  has only  a single baby  in each pregnancy, but sometimes,  one pregnancy in ninety is a twin pregnancy,  a triplet or  quadruplets. There are two ways in which a multiple pregnancy can occur. Either two or more eggs are released  from the ovary at one time and each egg is fertilized by a different spermatozoon  or the single fertilized egg may completely divide at the stage of the blastocyst and then two individuals develop with different placentas.