Twin gestations can be dichorionic diamniotic (DCDA, two placentas, and two amniotic sacs), monochorionic diamniotic (MCDA, one placenta, ...Clipboard,SearchHistory,andseveralotheradvancedfeaturesaretemporarilyunavailable.SkiptomainpagecontentCOVID-19InformationPublichealthinformation(CDC)Researchinformation(NIH)SARS-CoV-2data(NCBI)Preventionandtreatmentinformation(HHS)Español AccesskeysNCBIHomepageMyNCBIHomepageMainContentMainNavigationSearch:SearchAdvancedClipboardUserGuideSaveEmailSendtoClipboardMyBibliographyCollectionsCitationmanagerDisplayoptionsDisplayoptionsFormatAbstractPubMedPMIDSavecitationtofileFormat:Summary(text)PubMedPMIDAbstract(text)CSVCreatefileCancelEmailcitationSubject:1selecteditem:33085280-PubMedTo:Format:SummarySummary(text)AbstractAbstract(text)MeSHandotherdataSendemailCancelAddtoCollectionsCreateanewcollectionAddtoanexistingcollectionNameyourcollection:Namemustbelessthan100charactersChooseacollection:UnabletoloadyourcollectionduetoanerrorPleasetryagainAddCancelAddtoMyBibliographyMyBibliographyUnabletoloadyourdelegatesduetoanerrorPleasetryagainAddCancelYoursavedsearchNameofsavedsearch:Searchterms:TestsearchtermsWouldyoulikeemailupdatesofnewsearchresults?SavedSearchAlertRadioButtonsYesNoEmail:(change)Frequency:MonthlyWeeklyDailyWhichday?ThefirstSundayThefirstMondayThefirstTuesdayThefirstWednesdayThefirstThursdayThefirstFridayThefirstSaturdayThefirstdayThefirstweekdayWhichday?SundayMondayTuesdayWednesdayThursdayFridaySaturdayReportformat:SummarySummary(text)AbstractAbstract(text)PubMedSendatmost:1item5items10items20items50items100items200itemsSendevenwhentherearen'tanynewresultsOptionaltextinemail:SaveCancelCreateafileforexternalcitationmanagementsoftwareCreatefileCancelYourRSSFeedNameofRSSFeed:Numberofitemsdisplayed:510152050100CreateRSSCancelRSSLinkCopyFulltextlinksStatPearls[Internet]NCBIBookshelfFulltextlinksActionsCiteFavoritesDisplayoptionsDisplayoptionsFormatAbstractPubMedPMIDSharePermalinkCopyPagenavigationTitle&authorsExcerptSectionsSi