Non-identical twins are uniquely separate individuals who just happen to be gestating at the same time and place as each other. Non-identical twins form from ...LoginxEMAIL(*)Password(*)ForgotPassword?Notamember, JoinHuggiesClubOrLoginViaFacebookGetYourSamplexEMAIL(*)Password(*)ForgotPassword?Notamember, JoinHuggiesClubforfreesamplesandexclusivepromotionHomeParentingCenterGettingPregnantIdenticalandnon-identicaltwinsexplainedIdenticalAndNon-IdenticalTwinsExplainedSharenow:Whatcausesidenticalandnon-identicaltwins,andwhatincreasestheoddsofithappening?Readheretofindoutmore. IdenticalTwinsTheoddsofhavingtwinsarefargreaterthanforanyothertypeofmultiplebirths.Around90%ofallmultiplesaremadeupoftwins;theremaining10%iswithtriplets,quadrupletsandveryoccasionallyquintupletsandmore.Inrecentyearstherehasbeenabigincreaseinthenumbersoftwinsbeingborn.Thisisduetoadvancingmaternalage,assistedreproductiontechnology,aswellastheuseoffertilitydrugs.Importantly,betterneonatalcarehasmeantthatprematuretwinshaveabetterchanceofsurvivalthaneverbefore.Therearetwotypesoftwins–identicalormonozygotic(oneegg),andnon-identicalordizygotic(twoeggs)twins.Othernamesforidenticaltwinsarenon-fraternaltwins,andnon-identicaltwinsaresometimescalledfraternaltwins.Itisthoughtthattwinpregnanciesarefarmorecommonthanweareawareof–perhapsasmanyas5%ofallpregnanciesat12weeksinvolveatwin.Thoughnotallwillcontinuetodevelopastheyneedtoinordertoformtwobabies.Mostcommonly,thisisthoughttobeduetoamajorinterruptionoccurringwithhealthycellmaturationanddivision.Howdoidenticaltwinshappen?Identicaltwinsformwhenoneegghasbeenfertilisedbyonespermandthezygotesplitsintotwo.Thishappensattheveryearlieststageofdevelopment,whenthezygoteisnomorethanaclusterofafewcells.Dividingthisearlyinconceptionmeansthateachbabyhasexactlythesamegeneticinformationastheother.Identicaltwinscanalsooccurwhenoneawomanhasundergonefertilityassistanceandhashadonefertilisedeggreturnedtoheruterus.Ifthiseggthensplitsintotwo,anidenticaltwinpregnancycanresult.Identicalt