Skiptositealert.SkiptocontentYouarehereHome>PatientCare>OurCenters>CenterforPrenatalPediatrics>ConditionsWeCareFor>MonoamnioticTwinsCenterforPrenatalPediatricsMonoamnioticTwinsWhataremonoamniotictwins?Monoamniotictwinsoccurwhenasinglefertilizedovum(egg)resultsinidenticaltwinsthatshareacommonplacentaandamnioticsac. Monoamniotictwinsareveryuncommon,representingapproximatelyonepercentofidenticaltwinsandlessthan0.1percentofallpregnancies.Howisthisconditionmanagedduringpregnancy?Duetoasharedamnioticspace,monoamniotictwinscommonlyexperienceentanglementoftheirumbilicalcords.Insomeinstances,thisentanglementcanbesevereenoughtocompromisebloodsupplytothetwins,resultinginthelossofoneorbothofthetwins.Theseinstancescanbedifficulttopredict.Therefore,thesetwinsarecloselymonitoredthroughoutpregnancy,usuallyinvolvinginpatienthospitalizationfromaveryprematuretime.Givenanassociationbetweenmonoamniotictwinsandphysicalmalformations,thesetwinsundergofetalechocardiographyinadditiontousualultrasound-basedassessments.Howisthisconditionmanagedafterdelivery?Withcontemporarymanagement,survivalratesformonoamniotictwinsarearound90percent.Thesetwinsarenecessarilybornataprematuregestationalage,evenintheabsenceofidentifiedcomplicationsbeforebirth.Inadditiontophysicalmalformationsthatmaybepresent,prematurityisamajorfactorindetermininglong-termhealth.Backtotop