{"id":"https://openalex.org/W2374739478","doi":"https://doi.org/10.7863/jum.2001.20.7.757","title":"Frequency of a monochorionic pair in multiple gestations: relationship to mode of conception.","display_name":"Frequency of a monochorionic pair in multiple gestations: relationship to mode of conception.","publication_year":2001,"publication_date":"2001-07-01","ids":{"openalex":"https://openalex.org/W2374739478","doi":"https://doi.org/10.7863/jum.2001.20.7.757","mag":"2374739478","pmid":"https://pubmed.ncbi.nlm.nih.gov/11444734"},"language":"en","primary_location":{"id":"doi:10.7863/jum.2001.20.7.757","doi":"https://doi.org/10.7863/jum.2001.20.7.757","is_oa":false,"landing_page_url":"https://doi.org/10.7863/jum.2001.20.7.757","pdf_url":null,"source":{"id":"https://openalex.org/S111362775","display_name":"Journal of Ultrasound in Medicine","issn_l":"0278-4297","issn":["0278-4297","1550-9613"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["cwts-core","dongbi-b","doyens","jufo-1","ki-jl-1","medline","norway-1","poland-70","russia-white-list-2"],"host_organization":"https://openalex.org/P4310320595","host_organization_name":"Wiley","host_organization_lineage":["https://openalex.org/P4310320595"],"host_organization_lineage_names":["Wiley"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of Ultrasound in Medicine","raw_type":"journal-article"},"volume":null,"type":"article","indexed_in":["crossref","pubmed"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":null,"display_name":"J S Chow","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I1283280774","display_name":"Brigham and Women's Hospital","ror":"https://ror.org/04b6nzv94","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I121934306","https://openalex.org/I1283280774","https://openalex.org/I48633490"]},{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"J S Chow","raw_affiliation_strings":["Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA","institution_ids":["https://openalex.org/I1283280774","https://openalex.org/I136199984"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5057697494","display_name":"Carol B. Benson","orcid":"https://orcid.org/0000-0003-2639-2703","observed_orcids":["https://orcid.org/0000-0003-2639-2703"]},"institutions":[{"id":"https://openalex.org/I1283280774","display_name":"Brigham and Women's Hospital","ror":"https://ror.org/04b6nzv94","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I121934306","https://openalex.org/I1283280774","https://openalex.org/I48633490"]},{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"C B Benson","raw_affiliation_strings":["Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA","institution_ids":["https://openalex.org/I1283280774","https://openalex.org/I136199984"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5040907031","display_name":"Catherine Racowsky","orcid":"https://orcid.org/0000-0002-8961-7896","observed_orcids":["https://orcid.org/0000-0002-8961-7896"]},"institutions":[{"id":"https://openalex.org/I1283280774","display_name":"Brigham and Women's Hospital","ror":"https://ror.org/04b6nzv94","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I121934306","https://openalex.org/I1283280774","https://openalex.org/I48633490"]},{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"C Racowsky","raw_affiliation_strings":["Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA","institution_ids":["https://openalex.org/I1283280774","https://openalex.org/I136199984"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5091439600","display_name":"Peter M. Doubilet","orcid":"https://orcid.org/0000-0002-4264-2752","observed_orcids":["https://orcid.org/0000-0002-4264-2752"]},"institutions":[{"id":"https://openalex.org/I1283280774","display_name":"Brigham and Women's Hospital","ror":"https://ror.org/04b6nzv94","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I121934306","https://openalex.org/I1283280774","https://openalex.org/I48633490"]},{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"P M Doubilet","raw_affiliation_strings":["Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA","institution_ids":["https://openalex.org/I1283280774","https://openalex.org/I136199984"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5072243585","display_name":"Elizabeth Sarah Ginsburg","orcid":"https://orcid.org/0000-0002-5206-1724","observed_orcids":["https://orcid.org/0000-0002-5206-1724"]},"institutions":[{"id":"https://openalex.org/I1283280774","display_name":"Brigham and Women's Hospital","ror":"https://ror.org/04b6nzv94","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I121934306","https://openalex.org/I1283280774","https://openalex.org/I48633490"]},{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"E Ginsburg","raw_affiliation_strings":["Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA","institution_ids":["https://openalex.org/I1283280774","https://openalex.org/I136199984"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":{"value":4100,"currency":"USD","value_usd":4100},"apc_paid":null,"fwci":3.6515,"has_fulltext":false,"cited_by_count":112,"citation_normalized_percentile":{"value":0.92714256,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":89,"max":100},"biblio":{"volume":"20","issue":"7","first_page":"757","last_page":"760"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11732","display_name":"Assisted Reproductive Technology and Twin Pregnancy","score":1.0,"subfield":{"id":"https://openalex.org/subfields/2735","display_name":"Pediatrics, Perinatology and Child Health"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},"topics":[{"id":"https://openalex.org/T11732","display_name":"Assisted Reproductive Technology and Twin Pregnancy","score":1.0,"subfield":{"id":"https://openalex.org/subfields/2735","display_name":"Pediatrics, Perinatology and Child Health"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T11156","display_name":"Reproductive Health and Technologies","score":0.0,"subfield":{"id":"https://openalex.org/subfields/2743","display_name":"Reproductive Medicine"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T10978","display_name":"Prenatal Screening and Diagnostics","score":0.0,"subfield":{"id":"https://openalex.org/subfields/2735","display_name":"Pediatrics, Perinatology and Child Health"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/monochorionic-twins","display_name":"monochorionic twins","score":0.8970000147819519},{"id":"https://openalex.org/keywords/multiple-pregnancy","display_name":"multiple pregnancy","score":0.8090000152587891},{"id":"https://openalex.org/keywords/assisted-reproductive-technology","display_name":"assisted reproduction","score":0.847000002861023},{"id":"https://openalex.org/keywords/spontaneous-pregnancy","display_name":"spontaneous conception","score":0.7699999809265137},{"id":"https://openalex.org/keywords/in-vitro-fertilization","display_name":"in vitro fertilization","score":0.8629999756813049},{"id":"https://openalex.org/keywords/blastocyst-transfer","display_name":"blastocyst transfer","score":0.9570000171661377},{"id":"https://openalex.org/keywords/day-5-embryo-transfer","display_name":"day 5 embryo transfer","score":0.7900000214576721},{"id":"https://openalex.org/keywords/higher-order-multiple-pregnancy","display_name":"high-order multiple pregnancy","score":0.6570000052452087},{"id":"https://openalex.org/keywords/twin-pregnancy","display_name":"twin pregnancy","score":0.5170000195503235},{"id":"https://openalex.org/keywords/first-trimester-ultrasound","display_name":"first-trimester ultrasound","score":0.6840000152587891}],"concepts":[{"id":"https://openalex.org/C2910608164","wikidata":"https://www.wikidata.org/wiki/Q25671","display_name":"Quadruplets","level":4,"score":0.9391583800315857},{"id":"https://openalex.org/C46973012","wikidata":"https://www.wikidata.org/wiki/Q28627","display_name":"Gestation","level":3,"score":0.7545582056045532},{"id":"https://openalex.org/C500014431","wikidata":"https://www.wikidata.org/wiki/Q25862","display_name":"Assisted reproductive technology","level":4,"score":0.6706047058105469},{"id":"https://openalex.org/C191093355","wikidata":"https://www.wikidata.org/wiki/Q9250577","display_name":"Exact test","level":2,"score":0.6407756805419922},{"id":"https://openalex.org/C71924100","wikidata":"https://www.wikidata.org/wiki/Q11190","display_name":"Medicine","level":0,"score":0.6183369159698486},{"id":"https://openalex.org/C512716672","wikidata":"https://www.wikidata.org/wiki/Q200117","display_name":"In vitro fertilisation","level":3,"score":0.5976353883743286},{"id":"https://openalex.org/C131872663","wikidata":"https://www.wikidata.org/wiki/Q5284418","display_name":"Obstetrics","level":1,"score":0.5610349178314209},{"id":"https://openalex.org/C29456083","wikidata":"https://www.wikidata.org/wiki/Q1221899","display_name":"Gynecology","level":1,"score":0.5232478976249695},{"id":"https://openalex.org/C2778853074","wikidata":"https://www.wikidata.org/wiki/Q6901425","display_name":"Monochorionic twins","level":4,"score":0.4796772003173828},{"id":"https://openalex.org/C2994278967","wikidata":"https://www.wikidata.org/wiki/Q7314318","display_name":"Reproductive technology","level":4,"score":0.4764445424079895},{"id":"https://openalex.org/C2908647359","wikidata":"https://www.wikidata.org/wiki/Q2625603","display_name":"Population","level":2,"score":0.44406843185424805},{"id":"https://openalex.org/C2779234561","wikidata":"https://www.wikidata.org/wiki/Q11995","display_name":"Pregnancy","level":2,"score":0.40681779384613037},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.17475810647010803},{"id":"https://openalex.org/C2777688143","wikidata":"https://www.wikidata.org/wiki/Q179399","display_name":"Infertility","level":3,"score":0.10141104459762573},{"id":"https://openalex.org/C126322002","wikidata":"https://www.wikidata.org/wiki/Q11180","display_name":"Internal medicine","level":1,"score":0.0851026177406311},{"id":"https://openalex.org/C54355233","wikidata":"https://www.wikidata.org/wiki/Q7162","display_name":"Genetics","level":1,"score":0.08451706171035767},{"id":"https://openalex.org/C2776659692","wikidata":"https://www.wikidata.org/wiki/Q719426","display_name":"Lactation","level":3,"score":0.0},{"id":"https://openalex.org/C99454951","wikidata":"https://www.wikidata.org/wiki/Q932068","display_name":"Environmental health","level":1,"score":0.0}],"mesh":[{"descriptor_ui":"D002823","descriptor_name":"Chorion","qualifier_ui":"Q000000981","qualifier_name":"diagnostic imaging","is_major_topic":true},{"descriptor_ui":"D005260","descriptor_name":"Female","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D006801","descriptor_name":"Humans","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D011247","descriptor_name":"Pregnancy","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D011261","descriptor_name":"Pregnancy Trimester, First","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D011272","descriptor_name":"Pregnancy, Multiple","qualifier_ui":"Q000706","qualifier_name":"statistics & numerical data","is_major_topic":true},{"descriptor_ui":"D011446","descriptor_name":"Prospective Studies","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D012099","descriptor_name":"Reproductive Techniques","qualifier_ui":"Q000009","qualifier_name":"adverse effects","is_major_topic":true},{"descriptor_ui":"D012099","descriptor_name":"Reproductive Techniques","qualifier_ui":"Q000706","qualifier_name":"statistics & numerical data","is_major_topic":false},{"descriptor_ui":"D014430","descriptor_name":"Twins, Monozygotic","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D016216","descriptor_name":"Ultrasonography, Prenatal","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":true}],"locations_count":2,"locations":[{"id":"doi:10.7863/jum.2001.20.7.757","doi":"https://doi.org/10.7863/jum.2001.20.7.757","is_oa":false,"landing_page_url":"https://doi.org/10.7863/jum.2001.20.7.757","pdf_url":null,"source":{"id":"https://openalex.org/S111362775","display_name":"Journal of Ultrasound in Medicine","issn_l":"0278-4297","issn":["0278-4297","1550-9613"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["cwts-core","dongbi-b","doyens","jufo-1","ki-jl-1","medline","norway-1","poland-70","russia-white-list-2"],"host_organization":"https://openalex.org/P4310320595","host_organization_name":"Wiley","host_organization_lineage":["https://openalex.org/P4310320595"],"host_organization_lineage_names":["Wiley"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of Ultrasound in Medicine","raw_type":"journal-article"},{"id":"pmid:11444734","doi":null,"is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/11444734","pdf_url":null,"source":{"id":"https://openalex.org/S4306525036","display_name":"PubMed","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine","raw_type":"Comparative Study"}],"best_oa_location":null,"sustainable_development_goals":[{"display_name":"Good health and well-being","score":0.8371999859809875,"id":"https://metadata.un.org/sdg/3"}],"study_designs":[{"display_name":"Observational Study","id":"https://openalex.org/study-designs/observational-study"}],"awards":[],"funders":[],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":12,"referenced_works":["https://openalex.org/W1965902055","https://openalex.org/W1970750088","https://openalex.org/W2004303236","https://openalex.org/W2007590519","https://openalex.org/W2038646023","https://openalex.org/W2039453884","https://openalex.org/W2039924970","https://openalex.org/W2058243947","https://openalex.org/W2096070398","https://openalex.org/W2131531401","https://openalex.org/W2324042681","https://openalex.org/W2396703455"],"related_works":["https://openalex.org/W1667843617","https://openalex.org/W2117338972","https://openalex.org/W2015311894","https://openalex.org/W1676443590","https://openalex.org/W2064063691","https://openalex.org/W1542929134","https://openalex.org/W4414352589","https://openalex.org/W2088538380","https://openalex.org/W7162019572","https://openalex.org/W7163740238"],"abstract_inverted_index":{"OBJECTIVE:":[0],"To":[1],"determine":[2],"whether":[3],"the":[4,9,52,66,94,97,100,170,185],"mode":[5],"of":[6,11,21,43,60,69,77,108,111,114,118,154,243],"conception":[7],"affects":[8],"frequency":[10,42,53,153,171,242],"monochorionicity":[12,44],"in":[13,45,54,132,137,158,173,203,208,226],"multiple":[14,25,79,210],"gestations.":[15],"METHODS:":[16],"Our":[17,74],"study":[18,75,258],"population":[19,259],"consisted":[20,76],"all":[22],"women":[23],"with":[24,51,161,176,212],"gestations":[26,80,211],"who":[27],"had":[28],"a":[29,237,240,256],"first-trimester":[30],"sonogram":[31],"at":[32],"our":[33],"institution":[34],"between":[35],"May":[36],"1998":[37],"and":[38,64,88,116,207,228],"April":[39],"2000.":[40],"The":[41,92,152],"pregnancies":[46,55,135],"conceived":[47,134,205],"naturally":[48,133,204],"was":[49,168,187],"compared":[50],"achieved":[56],"via":[57],"any":[58],"form":[59],"assisted":[61,70,104,141,219,232],"reproductive":[62,71,105,142,220,233],"technology":[63,106,143,234],"among":[65],"different":[67],"types":[68],"technology.":[72],"RESULTS:":[73],"464":[78],"comprising":[81],"332":[82],"twin,":[83],"113":[84],"triplet,":[85],"16":[86],"quadruplet,":[87],"3":[89,182,215,253],"quintuplet":[90],"pregnancies.":[91],"higher":[93,241],"fetal":[95],"number,":[96],"more":[98,130,213],"likely":[99],"pregnancy":[101],"resulted":[102],"from":[103,140,172,218,231],"(72.6%":[107],"twins,":[109],"84.1%":[110],"triplets,":[112],"92.8%":[113],"quadruplets,":[115],"100%":[117],"quintuplets;":[119],"P":[120,147],"<":[121,148],".05,":[122],"Fisher":[123,194],"exact":[124,195],"test).":[125,151,196],"Monochorionic":[126,198],"pairs":[127,156,199,245],"were":[128],"found":[129],"commonly":[131],"than":[136,214,251],"those":[138],"resulting":[139],"(28.2%":[144],"versus":[145],"5.4%;":[146],".000001,":[149],"chi2":[150],"monochorionic":[155,244],"after":[157,246],"vitro":[159,174],"fertilization":[160,175],"blastocyst":[162,249],"transfer":[163,179,250],"on":[164,180],"day":[165,181,247,252],"5":[166,248],"(10.5%)":[167],"double":[169],"cleavage":[177],"stage":[178],"(4.9%),":[183],"but":[184,222,255],"difference":[186],"not":[188],"statistically":[189],"significant":[190],"(P":[191],"=":[192],".24,":[193],"CONCLUSIONS:":[197],"are":[200,224],"relatively":[201],"common":[202],"twins":[206,227],"higher-order":[209],"fetuses":[216],"arising":[217,230],"technology,":[221],"they":[223],"uncommon":[225],"triplets":[229],"There":[235],"is":[236,260],"trend":[238],"toward":[239],"transfer,":[254],"larger":[257],"needed":[261],"to":[262],"confirm":[263],"this":[264],"finding.":[265]},"counts_by_year":[{"year":2025,"cited_by_count":1},{"year":2022,"cited_by_count":1},{"year":2019,"cited_by_count":1},{"year":2018,"cited_by_count":1},{"year":2017,"cited_by_count":56},{"year":2016,"cited_by_count":5},{"year":2015,"cited_by_count":3},{"year":2014,"cited_by_count":3},{"year":2013,"cited_by_count":3},{"year":2012,"cited_by_count":2}],"updated_date":"2026-10-31T12:09:11.096373","created_date":"2016-06-24T00:00:00"}