{"id":"https://openalex.org/W2017855099","doi":"https://doi.org/10.1111/j.1471-0528.1988.tb06526.x","title":"Occult biochemical pregnancy: fact or fiction?","display_name":"Occult biochemical pregnancy: fact or fiction?","publication_year":1988,"publication_date":"1988-07-01","ids":{"openalex":"https://openalex.org/W2017855099","doi":"https://doi.org/10.1111/j.1471-0528.1988.tb06526.x","mag":"2017855099","pmid":"https://pubmed.ncbi.nlm.nih.gov/3273753"},"language":"en","primary_location":{"id":"doi:10.1111/j.1471-0528.1988.tb06526.x","doi":"https://doi.org/10.1111/j.1471-0528.1988.tb06526.x","is_oa":false,"landing_page_url":"https://doi.org/10.1111/j.1471-0528.1988.tb06526.x","pdf_url":null,"source":{"id":"https://openalex.org/S4210173111","display_name":"BJOG An International Journal of Obstetrics & Gynaecology","issn_l":"0306-5456","issn":["0306-5456","1365-215X","1470-0328","1471-0528"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["anvur-scientific","cwts-core","dongbi-b","doyens","jufo-2","ki-jl-2","medline","norway-2","poland-140","russia-white-list-1","vabb-shw"],"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":"BJOG: An International Journal of Obstetrics & Gynaecology","raw_type":"journal-article"},"volume":null,"type":"article","is_traditional":true,"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":"https://openalex.org/A5010895888","display_name":"E. M. Walker","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I2802526638","display_name":"Ninewells Hospital","ror":"https://ror.org/039c6rk82","country_code":"GB","type":"healthcare","lineage":["https://openalex.org/I2800860831","https://openalex.org/I2802526638"]}],"countries":["GB"],"is_corresponding":true,"raw_author_name":"E. M. WALKER","raw_affiliation_strings":["Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee","Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee","institution_ids":["https://openalex.org/I2802526638"]},{"raw_affiliation_string":"Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY","institution_ids":["https://openalex.org/I2802526638"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5091015345","display_name":"Mark David Lewis","orcid":"https://orcid.org/0000-0001-7725-0460","observed_orcids":["https://orcid.org/0000-0001-7725-0460"]},"institutions":[{"id":"https://openalex.org/I2802526638","display_name":"Ninewells Hospital","ror":"https://ror.org/039c6rk82","country_code":"GB","type":"healthcare","lineage":["https://openalex.org/I2800860831","https://openalex.org/I2802526638"]}],"countries":["GB"],"is_corresponding":false,"raw_author_name":"M. LEWIS","raw_affiliation_strings":["Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY","institution_ids":["https://openalex.org/I2802526638"]}]},{"author_position":"middle","author":{"id":null,"display_name":"W. COOPER","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I2802526638","display_name":"Ninewells Hospital","ror":"https://ror.org/039c6rk82","country_code":"GB","type":"healthcare","lineage":["https://openalex.org/I2800860831","https://openalex.org/I2802526638"]}],"countries":["GB"],"is_corresponding":false,"raw_author_name":"W. COOPER","raw_affiliation_strings":["Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY","institution_ids":["https://openalex.org/I2802526638"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5085737360","display_name":"M. MARNIE","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I2802526638","display_name":"Ninewells Hospital","ror":"https://ror.org/039c6rk82","country_code":"GB","type":"healthcare","lineage":["https://openalex.org/I2800860831","https://openalex.org/I2802526638"]}],"countries":["GB"],"is_corresponding":false,"raw_author_name":"M. MARNIE","raw_affiliation_strings":["Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY","institution_ids":["https://openalex.org/I2802526638"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5016796030","display_name":"Peter Howie","orcid":"https://orcid.org/0000-0002-7711-4757","observed_orcids":["https://orcid.org/0000-0002-7711-4757"]},"institutions":[{"id":"https://openalex.org/I2802526638","display_name":"Ninewells Hospital","ror":"https://ror.org/039c6rk82","country_code":"GB","type":"healthcare","lineage":["https://openalex.org/I2800860831","https://openalex.org/I2802526638"]}],"countries":["GB"],"is_corresponding":false,"raw_author_name":"P. W. HOWIE","raw_affiliation_strings":["Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Obstetrics and Gynaecology, Ninewells Hospital, Dundee DD1 9SY","institution_ids":["https://openalex.org/I2802526638"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5010895888"],"corresponding_institution_ids":["https://openalex.org/I2802526638"],"apc_list":{"value":5190,"currency":"USD","value_usd":5190},"apc_paid":null,"fwci":4.5328,"has_fulltext":false,"cited_by_count":38,"citation_normalized_percentile":{"value":0.95242663,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":88,"max":97},"biblio":{"volume":"95","issue":"7","first_page":"659","last_page":"663"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11156","display_name":"Reproductive Health and Technologies","score":0.6855000257492065,"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"}},"topics":[{"id":"https://openalex.org/T11156","display_name":"Reproductive Health and Technologies","score":0.6855000257492065,"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/T10600","display_name":"Reproductive Health and Contraception","score":0.11159999668598175,"subfield":{"id":"https://openalex.org/subfields/2739","display_name":"Public Health, Environmental and Occupational 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/T11510","display_name":"Reproductive System and Pregnancy","score":0.08649999648332596,"subfield":{"id":"https://openalex.org/subfields/2403","display_name":"Immunology"},"field":{"id":"https://openalex.org/fields/24","display_name":"Immunology and Microbiology"},"domain":{"id":"https://openalex.org/domains/1","display_name":"Life Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/biochemical-pregnancy","display_name":"biochemical pregnancy","score":0.9629999995231628},{"id":"https://openalex.org/keywords/human-chorionic-gonadotropin","display_name":"human chorionic gonadotropin","score":0.5979999899864197},{"id":"https://openalex.org/keywords/luteal-phase","display_name":"luteal phase","score":0.8420000076293945},{"id":"https://openalex.org/keywords/ovulation","display_name":"ovulation","score":0.7120000123977661},{"id":"https://openalex.org/keywords/pregnancy-diagnosis","display_name":"pregnancy diagnosis","score":0.3089999854564667},{"id":"https://openalex.org/keywords/ovulation-timing","display_name":"ovulation timing","score":0.39399999380111694}],"concepts":[{"id":"https://openalex.org/C2777702977","wikidata":"https://www.wikidata.org/wiki/Q187082","display_name":"Ovulation","level":3,"score":0.8355139493942261},{"id":"https://openalex.org/C143228043","wikidata":"https://www.wikidata.org/wiki/Q2363481","display_name":"Luteal phase","level":3,"score":0.7595587372779846},{"id":"https://openalex.org/C2779234561","wikidata":"https://www.wikidata.org/wiki/Q11995","display_name":"Pregnancy","level":2,"score":0.7356088161468506},{"id":"https://openalex.org/C2780026642","wikidata":"https://www.wikidata.org/wiki/Q40924","display_name":"Urine","level":2,"score":0.6123368144035339},{"id":"https://openalex.org/C71924100","wikidata":"https://www.wikidata.org/wiki/Q11190","display_name":"Medicine","level":0,"score":0.55307936668396},{"id":"https://openalex.org/C29456083","wikidata":"https://www.wikidata.org/wiki/Q1221899","display_name":"Gynecology","level":1,"score":0.49977898597717285},{"id":"https://openalex.org/C2779058012","wikidata":"https://www.wikidata.org/wiki/Q83864","display_name":"Menstrual cycle","level":3,"score":0.47218480706214905},{"id":"https://openalex.org/C518429986","wikidata":"https://www.wikidata.org/wiki/Q964401","display_name":"Fertility","level":3,"score":0.46165335178375244},{"id":"https://openalex.org/C16685009","wikidata":"https://www.wikidata.org/wiki/Q335057","display_name":"Andrology","level":1,"score":0.4232305884361267},{"id":"https://openalex.org/C68557331","wikidata":"https://www.wikidata.org/wiki/Q14865007","display_name":"Early pregnancy factor","level":4,"score":0.418677419424057},{"id":"https://openalex.org/C42407357","wikidata":"https://www.wikidata.org/wiki/Q521","display_name":"Physiology","level":1,"score":0.40572625398635864},{"id":"https://openalex.org/C134018914","wikidata":"https://www.wikidata.org/wiki/Q162606","display_name":"Endocrinology","level":1,"score":0.36420851945877075},{"id":"https://openalex.org/C71315377","wikidata":"https://www.wikidata.org/wiki/Q11364","display_name":"Hormone","level":2,"score":0.30494651198387146},{"id":"https://openalex.org/C46973012","wikidata":"https://www.wikidata.org/wiki/Q28627","display_name":"Gestation","level":3,"score":0.2846162021160126},{"id":"https://openalex.org/C2908647359","wikidata":"https://www.wikidata.org/wiki/Q2625603","display_name":"Population","level":2,"score":0.24883872270584106},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.24755871295928955},{"id":"https://openalex.org/C99454951","wikidata":"https://www.wikidata.org/wiki/Q932068","display_name":"Environmental health","level":1,"score":0.0},{"id":"https://openalex.org/C54355233","wikidata":"https://www.wikidata.org/wiki/Q7162","display_name":"Genetics","level":1,"score":0.0}],"mesh":[{"descriptor_ui":"D000328","descriptor_name":"Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D005260","descriptor_name":"Female","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D006063","descriptor_name":"Chorionic Gonadotropin","qualifier_ui":"Q000652","qualifier_name":"urine","is_major_topic":true},{"descriptor_ui":"D006801","descriptor_name":"Humans","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D008183","descriptor_name":"Luteal Phase","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D010060","descriptor_name":"Ovulation","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D011247","descriptor_name":"Pregnancy","qualifier_ui":"Q000652","qualifier_name":"urine","is_major_topic":true}],"locations_count":2,"locations":[{"id":"doi:10.1111/j.1471-0528.1988.tb06526.x","doi":"https://doi.org/10.1111/j.1471-0528.1988.tb06526.x","is_oa":false,"landing_page_url":"https://doi.org/10.1111/j.1471-0528.1988.tb06526.x","pdf_url":null,"source":{"id":"https://openalex.org/S4210173111","display_name":"BJOG An International Journal of Obstetrics & Gynaecology","issn_l":"0306-5456","issn":["0306-5456","1365-215X","1470-0328","1471-0528"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["anvur-scientific","cwts-core","dongbi-b","doyens","jufo-2","ki-jl-2","medline","norway-2","poland-140","russia-white-list-1","vabb-shw"],"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":"BJOG: An International Journal of Obstetrics & Gynaecology","raw_type":"journal-article"},{"id":"pmid:3273753","doi":null,"is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/3273753","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":"British journal of obstetrics and gynaecology","raw_type":"Journal Article"}],"best_oa_location":null,"sustainable_development_goals":[{"score":0.8048999905586243,"display_name":"Good health and well-being","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":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":7,"referenced_works":["https://openalex.org/W130271722","https://openalex.org/W163606091","https://openalex.org/W1526405163","https://openalex.org/W2093118266","https://openalex.org/W2149286574","https://openalex.org/W2278343092","https://openalex.org/W3165492722"],"related_works":["https://openalex.org/W4413949240","https://openalex.org/W1913710255","https://openalex.org/W3194346019","https://openalex.org/W4407102445","https://openalex.org/W2138709996","https://openalex.org/W165306797","https://openalex.org/W7204202174","https://openalex.org/W2004380126","https://openalex.org/W2995310799","https://openalex.org/W2005601419"],"abstract_inverted_index":{"Daily":[0],"urine":[1,203],"samples":[2,64,204],"were":[3,12,198,205],"obtained":[4,65],"from":[5,46],"38":[6],"women":[7],"of":[8,20,28,33,56,74,81,86,98,107,115,132,149,171,176,196,212,226],"proven":[9],"fertility,":[10],"who":[11],"attempting":[13],"to":[14,16],"conceive,":[15],"assess":[17],"the":[18,26,41,52,79,94,105,113,121,133,147,172,192,202,221,224],"frequency":[19,225],"clinically":[21,37,227],"unsuspected":[22,228],"\"biochemical":[23],"pregnancies'":[24,77],"on":[25,78,112,146,155,163],"basis":[27,80,114,148],"late":[29,82],"luteal":[30,83],"phase":[31,84],"rises":[32,45,85,195],"hCG.":[34,217],"In":[35],"25":[36],"confirmed":[38,200],"conception":[39],"cycles,":[40],"earliest":[42],"pregnancy-induced":[43],"hCG":[44,87,150],"baseline":[47],"occurred":[48,178],"8":[49,89],"days":[50,92],"after":[51,93,168,182],"endocrinologically":[53,95],"defined":[54,96],"date":[55,97,106],"ovulation":[57,108,183],"(mean":[58],"11.1":[59],"days,":[60],"SD":[61],"1.3).":[62],"Urine":[63],"throughout":[66],"50":[67,134,153],"non-conception":[68],"ovulatory":[69],"cycles":[70,136],"provided":[71],"no":[72],"evidence":[73],"any":[75],"'biochemical":[76,229],"occurring":[88],"or":[90,158,165,180],"more":[91,166],"ovulation.":[99],"If,":[100],"as":[101,141],"in":[102,129,143,191],"previous":[103],"studies,":[104],"had":[109,126],"been":[110,127,139,233],"estimated":[111],"menstrual":[116],"cycle":[117],"length":[118],"and":[119,184],"only":[120],"relatively":[122],"non-specific":[123],"NIH":[124],"antiserum":[125,209],"used":[128],"RIAs,":[130],"7":[131],"(14%)":[135],"would":[137],"have":[138,232],"classified":[140],"resulting":[142],"biochemical":[144],"pregnancies":[145],"greater":[151,159],"than":[152,160],"m-i.u./ml":[154,162],"one":[156],"occasion":[157],"20":[161,170],"two":[164],"occasions":[167],"day":[169],"cycle.":[173],"These":[174,218],"levels":[175],"'hCG'":[177,197],"at":[179],"soon":[181],"could":[185],"be":[186],"explained":[187],"by":[188],"LH":[189],"cross-reacting":[190],"RIA.":[193],"The":[194],"not":[199],"when":[201],"retested":[206],"with":[207],"an":[208],"(Wellcome":[210],"895)":[211],"very":[213],"high":[214],"specificity":[215],"for":[216],"results":[219],"raise":[220],"possibility":[222],"that":[223],"pregnancy'":[230],"may":[231],"substantially":[234],"overestimated.":[235]},"counts_by_year":[{"year":2023,"cited_by_count":2},{"year":2020,"cited_by_count":1},{"year":2018,"cited_by_count":1},{"year":2017,"cited_by_count":1},{"year":2016,"cited_by_count":3}],"updated_date":"2026-10-31T12:09:11.096373","created_date":"2016-06-24T00:00:00"}