{"id":"https://openalex.org/W7214118641","doi":"https://doi.org/10.1371/journal.pone.0357286","title":"Sexual intercourse frequency and fecundability in the Norwegian mother, father and child cohort study","display_name":"Sexual intercourse frequency and fecundability in the Norwegian mother, father and child cohort study","publication_year":2026,"publication_date":"2026-09-23","ids":{"openalex":"https://openalex.org/W7214118641","doi":"https://doi.org/10.1371/journal.pone.0357286","pmid":"https://pubmed.ncbi.nlm.nih.gov/42776935","pmcid":"https://www.ncbi.nlm.nih.gov/pmc/articles/13600493"},"language":"en","primary_location":{"id":"doi:10.1371/journal.pone.0357286","doi":"https://doi.org/10.1371/journal.pone.0357286","is_oa":true,"landing_page_url":"https://doi.org/10.1371/journal.pone.0357286","pdf_url":"https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0357286&type=printable","source":{"id":"https://openalex.org/S202381698","display_name":"PLoS ONE","issn_l":"1932-6203","issn":["1932-6203"],"is_oa":true,"is_in_doaj":true,"is_core":true,"listed_in":["anvur-class-a","anvur-scientific","cwts-core","doaj","dongbi-c","doyens","erih-plus","jufo-1","ki-jl-1","medline","norway-1","poland-100","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310315706","host_organization_name":"Public Library of Science","host_organization_lineage":["https://openalex.org/P4310315706"],"host_organization_lineage_names":["Public Library of Science"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"PLOS One","raw_type":"journal-article"},"volume":null,"type":"article","is_traditional":true,"indexed_in":["crossref","doaj","pubmed"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0357286&type=printable","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5152532956","display_name":"Kristina W. Drei\u00e5s","orcid":"https://orcid.org/0009-0007-0724-0436","observed_orcids":["https://orcid.org/0009-0007-0724-0436"]},"institutions":[{"id":"https://openalex.org/I1333353642","display_name":"Norwegian Institute of Public Health","ror":"https://ror.org/046nvst19","country_code":"NO","type":"government","lineage":["https://openalex.org/I1333353642","https://openalex.org/I4210149801","https://openalex.org/I4210163359"]},{"id":"https://openalex.org/I4210117575","display_name":"Telemark Hospital","ror":"https://ror.org/02fafrk51","country_code":"NO","type":"healthcare","lineage":["https://openalex.org/I4210117575","https://openalex.org/I4210123979"]},{"id":"https://openalex.org/I4432739","display_name":"University of Bergen","ror":"https://ror.org/03zga2b32","country_code":"NO","type":"education","lineage":["https://openalex.org/I4432739"]}],"countries":["NO"],"is_corresponding":true,"raw_author_name":"Kristina W. Drei\u00e5s","raw_affiliation_strings":["Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway","Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway","Fertility department, Telemark Hospital, Porsgrunn, Norway"],"raw_orcid":"https://orcid.org/0009-0007-0724-0436","affiliations":[{"raw_affiliation_string":"Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway","institution_ids":["https://openalex.org/I1333353642"]},{"raw_affiliation_string":"Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway","institution_ids":["https://openalex.org/I4432739"]},{"raw_affiliation_string":"Fertility department, Telemark Hospital, Porsgrunn, Norway","institution_ids":["https://openalex.org/I4210117575"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5038068030","display_name":"Liv Grimstvedt Kvalvik","orcid":"https://orcid.org/0000-0001-6520-9057","observed_orcids":["https://orcid.org/0000-0001-6520-9057"]},"institutions":[{"id":"https://openalex.org/I4432739","display_name":"University of Bergen","ror":"https://ror.org/03zga2b32","country_code":"NO","type":"education","lineage":["https://openalex.org/I4432739"]}],"countries":["NO"],"is_corresponding":false,"raw_author_name":"Liv G. Kvalvik","raw_affiliation_strings":["Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway","institution_ids":["https://openalex.org/I4432739"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5093882514","display_name":"Mari Land\u00e5s Warp","orcid":"https://orcid.org/0009-0009-7613-6880","observed_orcids":["https://orcid.org/0009-0009-7613-6880"]},"institutions":[{"id":"https://openalex.org/I2802281627","display_name":"Sykehuset i Vestfold","ror":"https://ror.org/04a0aep16","country_code":"NO","type":"healthcare","lineage":["https://openalex.org/I2802281627"]}],"countries":["NO"],"is_corresponding":false,"raw_author_name":"Mari L. Warp","raw_affiliation_strings":["Department of Gynecology and Obstetrics, Vestfold Hospital, T\u00f8nsberg, Norway"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Gynecology and Obstetrics, Vestfold Hospital, T\u00f8nsberg, Norway","institution_ids":["https://openalex.org/I2802281627"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5135425597","display_name":"Siri E. H\u00e5berg","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I1333353642","display_name":"Norwegian Institute of Public Health","ror":"https://ror.org/046nvst19","country_code":"NO","type":"government","lineage":["https://openalex.org/I1333353642","https://openalex.org/I4210149801","https://openalex.org/I4210163359"]},{"id":"https://openalex.org/I4432739","display_name":"University of Bergen","ror":"https://ror.org/03zga2b32","country_code":"NO","type":"education","lineage":["https://openalex.org/I4432739"]}],"countries":["NO"],"is_corresponding":false,"raw_author_name":"Siri E. H\u00e5berg","raw_affiliation_strings":["Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway","Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway","institution_ids":["https://openalex.org/I1333353642"]},{"raw_affiliation_string":"Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway","institution_ids":["https://openalex.org/I4432739"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5137100082","display_name":"Cecilia H. Ramlau-Hansen","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I204337017","display_name":"Aarhus University","ror":"https://ror.org/01aj84f44","country_code":"DK","type":"education","lineage":["https://openalex.org/I204337017"]}],"countries":["DK"],"is_corresponding":false,"raw_author_name":"Cecilia H. Ramlau-Hansen","raw_affiliation_strings":["Department of Public Health, Aarhus University, Aarhus, Denmark"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Public Health, Aarhus University, Aarhus, Denmark","institution_ids":["https://openalex.org/I204337017"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5082748019","display_name":"Hans Ivar Hanevik","orcid":"https://orcid.org/0000-0002-5131-6342","observed_orcids":["https://orcid.org/0000-0002-5131-6342"]},"institutions":[{"id":"https://openalex.org/I1333353642","display_name":"Norwegian Institute of Public Health","ror":"https://ror.org/046nvst19","country_code":"NO","type":"government","lineage":["https://openalex.org/I1333353642","https://openalex.org/I4210149801","https://openalex.org/I4210163359"]},{"id":"https://openalex.org/I4210117575","display_name":"Telemark Hospital","ror":"https://ror.org/02fafrk51","country_code":"NO","type":"healthcare","lineage":["https://openalex.org/I4210117575","https://openalex.org/I4210123979"]}],"countries":["NO"],"is_corresponding":false,"raw_author_name":"Hans Ivar Hanevik","raw_affiliation_strings":["Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway","Fertility department, Telemark Hospital, Porsgrunn, Norway"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway","institution_ids":["https://openalex.org/I1333353642"]},{"raw_affiliation_string":"Fertility department, Telemark Hospital, Porsgrunn, Norway","institution_ids":["https://openalex.org/I4210117575"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":5,"corresponding_author_ids":["https://openalex.org/A5152532956"],"corresponding_institution_ids":["https://openalex.org/I1333353642","https://openalex.org/I4210117575","https://openalex.org/I4432739"],"apc_list":{"value":2382,"currency":"USD","value_usd":2382},"apc_paid":{"value":2382,"currency":"USD","value_usd":2382},"fwci":0.0,"has_fulltext":true,"cited_by_count":0,"citation_normalized_percentile":{"value":0.67477755,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":null,"biblio":{"volume":"21","issue":"9","first_page":"e0357286","last_page":"e0357286"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11156","display_name":"Reproductive Health and Technologies","score":0.7865999937057495,"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":0.7865999937057495,"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":0.18070000410079956,"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/T10459","display_name":"Sexual function and dysfunction studies","score":0.004600000102072954,"subfield":{"id":"https://openalex.org/subfields/2738","display_name":"Psychiatry and Mental 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/sexual-frequency","display_name":"sexual frequency","score":0.8820000290870667},{"id":"https://openalex.org/keywords/fecundability","display_name":"fecundability","score":0.9879999756813049},{"id":"https://openalex.org/keywords/time-to-pregnancy","display_name":"time to pregnancy","score":0.921999990940094},{"id":"https://openalex.org/keywords/spontaneous-pregnancy","display_name":"spontaneous conception","score":0.703000009059906},{"id":"https://openalex.org/keywords/fertility","display_name":"fertility","score":0.5770000219345093},{"id":"https://openalex.org/keywords/menstrual-cycle","display_name":"menstrual cycle","score":0.42399999499320984},{"id":"https://openalex.org/keywords/endometriosis","display_name":"endometriosis","score":0.8740000128746033},{"id":"https://openalex.org/keywords/parity","display_name":"parity","score":0.49399998784065247},{"id":"https://openalex.org/keywords/body-mass-index","display_name":"body mass index","score":0.6990000009536743},{"id":"https://openalex.org/keywords/menstrual-regularity","display_name":"menstrual cycle regularity","score":0.8299999833106995}],"concepts":[{"id":"https://openalex.org/C63428231","wikidata":"https://www.wikidata.org/wiki/Q9043","display_name":"Norwegian","level":2,"score":0.785099983215332},{"id":"https://openalex.org/C2780202899","wikidata":"https://www.wikidata.org/wiki/Q5873","display_name":"Sexual intercourse","level":3,"score":0.7347999811172485},{"id":"https://openalex.org/C2779234561","wikidata":"https://www.wikidata.org/wiki/Q11995","display_name":"Pregnancy","level":2,"score":0.7243000268936157},{"id":"https://openalex.org/C71924100","wikidata":"https://www.wikidata.org/wiki/Q11190","display_name":"Medicine","level":0,"score":0.6823999881744385},{"id":"https://openalex.org/C149923435","wikidata":"https://www.wikidata.org/wiki/Q37732","display_name":"Demography","level":1,"score":0.5942000150680542},{"id":"https://openalex.org/C201903717","wikidata":"https://www.wikidata.org/wiki/Q1778788","display_name":"Cohort study","level":2,"score":0.5676000118255615},{"id":"https://openalex.org/C72563966","wikidata":"https://www.wikidata.org/wiki/Q1303415","display_name":"Cohort","level":2,"score":0.5464000105857849},{"id":"https://openalex.org/C518429986","wikidata":"https://www.wikidata.org/wiki/Q964401","display_name":"Fertility","level":3,"score":0.5246999859809875},{"id":"https://openalex.org/C2779058012","wikidata":"https://www.wikidata.org/wiki/Q83864","display_name":"Menstrual cycle","level":3,"score":0.4332999885082245},{"id":"https://openalex.org/C131872663","wikidata":"https://www.wikidata.org/wiki/Q5284418","display_name":"Obstetrics","level":1,"score":0.4189999997615814},{"id":"https://openalex.org/C29456083","wikidata":"https://www.wikidata.org/wiki/Q1221899","display_name":"Gynecology","level":1,"score":0.4153999984264374},{"id":"https://openalex.org/C205545832","wikidata":"https://www.wikidata.org/wiki/Q17156455","display_name":"Young adult","level":2,"score":0.37860000133514404},{"id":"https://openalex.org/C188816634","wikidata":"https://www.wikidata.org/wiki/Q2113324","display_name":"Prospective cohort study","level":2,"score":0.3727000057697296},{"id":"https://openalex.org/C160050368","wikidata":"https://www.wikidata.org/wiki/Q132453","display_name":"Developed country","level":3,"score":0.3725000023841858},{"id":"https://openalex.org/C2779771394","wikidata":"https://www.wikidata.org/wiki/Q12171","display_name":"Menstruation","level":2,"score":0.3499000072479248},{"id":"https://openalex.org/C4258228","wikidata":"https://www.wikidata.org/wiki/Q492514","display_name":"Menarche","level":2,"score":0.3441999852657318},{"id":"https://openalex.org/C2908647359","wikidata":"https://www.wikidata.org/wiki/Q2625603","display_name":"Population","level":2,"score":0.30480000376701355},{"id":"https://openalex.org/C2909635826","wikidata":"https://www.wikidata.org/wiki/Q83864","display_name":"Menstrual period","level":2,"score":0.28619998693466187},{"id":"https://openalex.org/C68557331","wikidata":"https://www.wikidata.org/wiki/Q14865007","display_name":"Early pregnancy factor","level":4,"score":0.2784000039100647},{"id":"https://openalex.org/C183627027","wikidata":"https://www.wikidata.org/wiki/Q6858819","display_name":"Millennium Cohort Study (United States)","level":3,"score":0.26809999346733093},{"id":"https://openalex.org/C167135981","wikidata":"https://www.wikidata.org/wiki/Q2146302","display_name":"Retrospective cohort study","level":2,"score":0.26420000195503235},{"id":"https://openalex.org/C2781289737","wikidata":"https://www.wikidata.org/wiki/Q17070897","display_name":"National Survey of Family Growth","level":5,"score":0.25780001282691956}],"mesh":[{"descriptor_ui":"D000328","descriptor_name":"Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D003075","descriptor_name":"Coitus","qualifier_ui":"Q000502","qualifier_name":"physiology","is_major_topic":true},{"descriptor_ui":"D005220","descriptor_name":"Fathers","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":"D005298","descriptor_name":"Fertility","qualifier_ui":"Q000502","qualifier_name":"physiology","is_major_topic":true},{"descriptor_ui":"D006801","descriptor_name":"Humans","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D009035","descriptor_name":"Mothers","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D009664","descriptor_name":"Norway","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":"D011795","descriptor_name":"Surveys and Questionnaires","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D015331","descriptor_name":"Cohort Studies","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D061685","descriptor_name":"Time-to-Pregnancy","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false}],"locations_count":5,"locations":[{"id":"doi:10.1371/journal.pone.0357286","doi":"https://doi.org/10.1371/journal.pone.0357286","is_oa":true,"landing_page_url":"https://doi.org/10.1371/journal.pone.0357286","pdf_url":"https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0357286&type=printable","source":{"id":"https://openalex.org/S202381698","display_name":"PLoS ONE","issn_l":"1932-6203","issn":["1932-6203"],"is_oa":true,"is_in_doaj":true,"is_core":true,"listed_in":["anvur-class-a","anvur-scientific","cwts-core","doaj","dongbi-c","doyens","erih-plus","jufo-1","ki-jl-1","medline","norway-1","poland-100","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310315706","host_organization_name":"Public Library of Science","host_organization_lineage":["https://openalex.org/P4310315706"],"host_organization_lineage_names":["Public Library of Science"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"PLOS One","raw_type":"journal-article"},{"id":"pmid:42776935","doi":null,"is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/42776935","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":"PloS one","raw_type":"Journal Article"},{"id":"pmh:oai:pubmedcentral.nih.gov:13600493","doi":null,"is_oa":true,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/42776935/","pdf_url":null,"source":{"id":"https://openalex.org/S2764455111","display_name":"PubMed Central","issn_l":null,"issn":null,"is_oa":true,"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":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"PLoS One","raw_type":"Text"},{"id":"pmh:oai:doaj.org/article:2965e6ed413148efb6046add79122e3a","doi":null,"is_oa":false,"landing_page_url":"https://doaj.org/article/2965e6ed413148efb6046add79122e3a","pdf_url":null,"source":{"id":"https://openalex.org/S4306401280","display_name":"DOAJ (DOAJ: Directory of Open Access Journals)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"PLoS ONE, Vol 21, Iss 9, p e0357286 (2026)","raw_type":"article"},{"id":"pmh:oai:pure.atira.dk:openaire/eaa3ec90-d22c-4f2a-978a-a7d0acb6c221","doi":null,"is_oa":true,"landing_page_url":"https://www.scopus.com/pages/publications/105051459985","pdf_url":null,"source":{"id":"https://openalex.org/S4306400063","display_name":"Scopus (Elsevier)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"repository"},"license":"other-oa","license_id":"https://openalex.org/licenses/other-oa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Drei\u00e5s, K W, Kvalvik, L G, Warp, M L, H\u00e5berg, S E, Ramlau-Hansen, C H & Hanevik, H I 2026, 'Sexual intercourse frequency and fecundability in the Norwegian mother, father and child cohort study', PLoS One, vol. 21, no. 9 , e0357286. https://doi.org/10.1371/journal.pone.0357286","raw_type":"info:eu-repo/semantics/article"}],"best_oa_location":{"id":"doi:10.1371/journal.pone.0357286","doi":"https://doi.org/10.1371/journal.pone.0357286","is_oa":true,"landing_page_url":"https://doi.org/10.1371/journal.pone.0357286","pdf_url":"https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0357286&type=printable","source":{"id":"https://openalex.org/S202381698","display_name":"PLoS ONE","issn_l":"1932-6203","issn":["1932-6203"],"is_oa":true,"is_in_doaj":true,"is_core":true,"listed_in":["anvur-class-a","anvur-scientific","cwts-core","doaj","dongbi-c","doyens","erih-plus","jufo-1","ki-jl-1","medline","norway-1","poland-100","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310315706","host_organization_name":"Public Library of Science","host_organization_lineage":["https://openalex.org/P4310315706"],"host_organization_lineage_names":["Public Library of Science"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"PLOS One","raw_type":"journal-article"},"sustainable_development_goals":[{"display_name":"Good health and well-being","id":"https://metadata.un.org/sdg/3","score":0.9537000060081482}],"study_designs":[{"display_name":"Observational Study","id":"https://openalex.org/study-designs/observational-study"}],"awards":[{"id":"https://openalex.org/G2014461362","display_name":null,"funder_award_id":"262700.","funder_id":"https://openalex.org/F4320323299","funder_display_name":"Norges Forskningsr\u00e5d"},{"id":"https://openalex.org/G7617179328","display_name":null,"funder_award_id":"101071773","funder_id":"https://openalex.org/F4320338335","funder_display_name":"H2020 European Research Council"}],"funders":[{"id":"https://openalex.org/F4320323299","display_name":"Norges Forskningsr\u00e5d","ror":"https://ror.org/00epmv149"},{"id":"https://openalex.org/F4320328235","display_name":"Sykehuset Telemark","ror":"https://ror.org/02fafrk51"},{"id":"https://openalex.org/F4320335102","display_name":"Helse S\u00f8r-\u00d8st RHF","ror":"https://ror.org/02qx2s478"},{"id":"https://openalex.org/F4320338335","display_name":"H2020 European Research Council","ror":"https://ror.org/0472cxd90"}],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W7214118641.pdf","grobid_xml":"https://content.openalex.org/works/W7214118641.grobid-xml"},"referenced_works_count":29,"referenced_works":["https://openalex.org/W1921571837","https://openalex.org/W1992592969","https://openalex.org/W2011527347","https://openalex.org/W2060443224","https://openalex.org/W2081596430","https://openalex.org/W2104723952","https://openalex.org/W2130397937","https://openalex.org/W2144441465","https://openalex.org/W2147081955","https://openalex.org/W2152611467","https://openalex.org/W2514018909","https://openalex.org/W2530466707","https://openalex.org/W2790492471","https://openalex.org/W2791992800","https://openalex.org/W2941504813","https://openalex.org/W2992627085","https://openalex.org/W3035366331","https://openalex.org/W3041112196","https://openalex.org/W3157123966","https://openalex.org/W4213421493","https://openalex.org/W4295885618","https://openalex.org/W4366814478","https://openalex.org/W4389060373","https://openalex.org/W4402621336","https://openalex.org/W4403852233","https://openalex.org/W4406433448","https://openalex.org/W4412355000","https://openalex.org/W4413103399","https://openalex.org/W4413348638"],"related_works":["https://openalex.org/W4381620191","https://openalex.org/W2130397937","https://openalex.org/W7097686625","https://openalex.org/W2005914565","https://openalex.org/W4389060373","https://openalex.org/W2032961053","https://openalex.org/W3046983123","https://openalex.org/W2791992800","https://openalex.org/W3041112196","https://openalex.org/W4391614037"],"abstract_inverted_index":{"OBJECTIVE:":[0],"The":[1,35,103,160],"aim":[2],"of":[3,13,100,107,116,235,292,333],"this":[4],"study":[5,56],"was":[6,79,91,111,189,207,268,326],"to":[7,21,28,72,77,95,145,163,178,202,254,324],"explore":[8],"the":[9,16,86,134,187,193,255,263,319],"association":[10,267],"between":[11,51,289],"frequency":[12,168,216,339],"intercourse":[14,83,101,114,167,196,204,215,227,248,290,313],"in":[15,30,47,211,237,270,287,310,318],"four":[17,320],"weeks":[18,321],"leading":[19,322],"up":[20,323],"conception":[22,108],"and":[23,39,53,85,137,155,280,297],"fecundability":[24,288],"among":[25,245],"women":[26,64,75,246,304],"trying":[27,76],"conceive":[29,78],"a":[31,44,208,231,329],"pregnancy":[32,45,73,96,164],"cohort.":[33,265],"METHODS:":[34],"Norwegian":[36],"Mother,":[37],"Father":[38],"Child":[40],"Cohort":[41],"Study":[42],"is":[43],"cohort":[46],"Norway":[48],"with":[49,65,131,166,225,305,328],"recruitment":[50],"1999":[52],"2008.":[54],"This":[55,266],"includes":[57],"self-reported":[58],"questionnaire":[59],"data":[60],"from":[61,169],"64":[62],"193":[63],"planned,":[66],"naturally":[67],"conceived":[68],"pregnancies.":[69],"Mean":[70],"time":[71,94,162],"for":[74,81,89,93,113,133,147,172,181,192,274],"calculated":[80,112],"different":[82],"frequencies":[84,115,291],"Jonckheere-Terpstra":[87],"test":[88],"trend":[90,210],"performed":[92,144],"across":[97,213,337],"ordered":[98,214],"groups":[99,217],"frequency.":[102],"cycle":[104,239,278,331],"specific":[105],"probability":[106,129,332],"(fecundability":[109,240],"ratio)":[110],"less":[117,173,293],"than":[118,174,294],"once,":[119,295],"1-2,":[120],"3-4,":[121],">":[122,182,197],"4":[123,183,198],"times":[124,184,199,250,259,299,315],"per":[125,176,251,260,300,316],"week":[126,177,252,317],"through":[127],"proportional":[128],"regression":[130],"adjustment":[132],"women's":[135],"age":[136],"education":[138],"level.":[139],"Several":[140],"supplementary":[141,271],"analyses":[142,272],"were":[143,283,341],"account":[146],"additional":[148],"covariates":[149],"such":[150],"as":[151],"BMI,":[152,275],"parity,":[153,276],"endometriosis":[154],"irregular":[156],"menstrual":[157,277],"cycles.":[158],"RESULTS:":[159],"mean":[161],"decreased":[165],"4.8":[170],"months":[171,180],"once":[175],"3.7":[179],"weekly,":[185],"however":[186],"decrease":[188],"primarily":[190],"evident":[191],"group":[194,257],"reporting":[195,247],"weekly":[200],"compared":[201,253],"lower":[203,338],"frequencies.":[205,228],"There":[206,282],"significant":[209],"TTP":[212,224],"(p":[218],"<":[219],"0.0001),":[220],"indicating":[221],"progressively":[222],"shorter":[223],"higher":[226,233,330],"We":[229],"found":[230],"16%":[232],"chance":[234],"conceiving":[236],"any":[238],"ratio":[241],"1.16":[242],"(95%":[243],"CI:1.14-1.19))":[244],">4":[249,314],"reference":[256],"(1-2":[258],"week)":[261],"within":[262],"analytic":[264],"consistent":[269],"accounting":[273],"regularity":[279],"endometriosis.":[281],"no":[284],"clear":[285],"differences":[286,336],"1-2":[296],"3-4":[298],"week.":[301],"CONCLUSION:":[302],"Among":[303],"planned":[306],"pregnancies":[307],"that":[308],"resulted":[309],"natural":[311],"conception,":[312,325],"associated":[327],"conceiving,":[334],"whereas":[335],"categories":[340],"limited.":[342]},"counts_by_year":[],"updated_date":"2026-10-31T12:09:11.096373","created_date":"2026-09-24T00:00:00"}