Hydatidiform mole (HM) is a rare mass or growth that forms inside the womb (uterus) at the beginning of a pregnancy. It is a type of gestational ...YouAreHere:Home→MedicalEncyclopedia→HydatidiformmoleURLofthispage://medlineplus.gov/ency/article/000909.htmHydatidiformmoleHydatidiformmole(HM)isararemassorgrowththatformsinsidethewomb(uterus)atthebeginningofapregnancy.Itisatypeofgestationaltrophoblasticdisease(GTD).CausesHM,ormolarpregnancy,resultsfromabnormalfertilizationoftheoocyte(egg).Itresultsinanabnormalfetus.Theplacentagrowsnormallywithlittleornogrowthofthefetaltissue.Theplacentaltissueformsamassintheuterus.Onultrasound,thismassoftenhasagrape-likeappearance,asitcontainsmanysmallcysts.Chanceofmoleformationishigherinolderwomen.Ahistoryofmoleinearlieryearsisalsoariskfactor.Molarpregnancycanbeoftwotypes:Partialmolarpregnancy:Thereisanabnormalplacentaandsomefetaldevelopment.Completemolarpregnancy:Thereisanabnormalplacentaandnofetus.Thereisnowaytopreventformationofthesemasses.SymptomsSymptomsofamolarpregnancymayinclude:Abnormalgrowthoftheuterus,eitherbiggerorsmallerthanusualSeverenauseaandvomitingVaginalbleedingduringthefirst3monthsofpregnancySymptomsofhyperthyroidism,includingheatintolerance, loosestools,rapidheartrate,restlessness ornervousness,warmandmoistskin,tremblinghands,orunexplainedweightlossSymptomssimilartopreeclampsiathatoccurinthefirsttrimesterorearlysecondtrimester,includinghighbloodpressureandswellinginthefeet,ankles,andlegs(thisisalmostalwaysasignofahydatidiformmole,becausepreeclampsiaisextremelyrarethisearlyinanormalpregnancy)ExamsandTestsYourhealthcareproviderwillperformapelvicexam,whichmayshowsignssimilartoanormalpregnancy.However,thesizeofthewombmaybeabnormalandtheremaybenoheartsoundsfromthebaby.Also,theremaybesomevaginalbleeding.Apregnancyultrasoundwillshowasnowstormappearancewithanabnormalplacenta,withorwithoutsomedevelopmentofababy.Testsdonemayinclude:hCG(quantitativelevels)bloodtestAbdominalorvaginalultrasoundofthepelvisChestx-rayCTorMRIoftheabd