{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T07:26:33Z","timestamp":1767338793364,"version":"3.40.5"},"reference-count":47,"publisher":"Wiley","issue":"8","license":[{"start":{"date-parts":[[2024,8,7]],"date-time":"2024-08-07T00:00:00Z","timestamp":1722988800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Paediatric Perinatal Epid"],"published-print":{"date-parts":[[2024,11]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>The use of fertility indicators to predict ovulation has largely been studied for contraceptive purposes, while less so as fertility\u2010promoting tools.<\/jats:p><\/jats:sec><jats:sec><jats:title>Objective<\/jats:title><jats:p>To investigate the association between fertility indicators and fecundability in Danish women trying to conceive.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Web\u2010based preconception cohort study. We analysed data from 11,328 females aged 18\u201349\u2009years trying to conceive without fertility treatment for \u22646 menstrual cycles, from the Danish SnartGravid.dk and SnartFor\u00e6ldre.dk cohorts (2007\u20132023). Participants reported the use of fertility indicators (counting days since the last menstrual period, cervical fluid monitoring, urinary ovulation testing, feeling ovulation, using a smartphone fertility app and <jats:italic>measuring basal body temperature [BBT]<\/jats:italic>). Time to pregnancy was measured in menstrual cycles ascertained by self\u2010reported pregnancy status. We estimated fecundability ratios (FR) and 95% confidence intervals (CI) using proportional probabilities regression models adjusted for age, socio\u2010economic position, health indicators, reproductive history and gynaecological factors.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Fertility indicators were used by 63.3% of participants at study entry. <jats:italic>Counting days<\/jats:italic> was the most common (46.9%), while <jats:italic>measuring BBT<\/jats:italic> was the least (3.0%). Other indicators ranged from 17.0% to 23.6%, with 69.7% using more than one indicator. Compared with non\u2010use, use of any fertility indicator was associated with greater fecundability (adjusted FR 1.14, 95% CI 1.08, 1.19). <jats:italic>Cervical fluid monitoring<\/jats:italic> showed the strongest association (aFR 1.46, 95% CI 1.03, 2.07), followed by <jats:italic>urinary ovulation testing<\/jats:italic> (aFR 1.35, 95% CI 1.16, 1.58) and <jats:italic>counting days<\/jats:italic> (aFR 1.18, 95% CI 1.09, 1.29). <jats:italic>Feeling ovulation<\/jats:italic> and <jats:italic>fertility apps<\/jats:italic> were modestly associated with fecundability, while <jats:italic>measuring BBT<\/jats:italic> was not associated. Sensitivity analysis restricting to \u22642 cycles of attempt time and two cycles of follow\u2010up showed an aFR for any indicator use of 1.21 (95% CI 1.13, 1.31).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>In this Danish preconception cohort, use of fertility indicators was associated with a higher fecundability, varying by type of indicator.<\/jats:p><\/jats:sec>","DOI":"10.1111\/ppe.13108","type":"journal-article","created":{"date-parts":[[2024,8,7]],"date-time":"2024-08-07T11:03:00Z","timestamp":1723028580000},"page":"641-650","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The association between the use of fertility indicators and fecundability in a Danish preconception cohort"],"prefix":"10.1111","volume":"38","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-4964-7824","authenticated-orcid":false,"given":"Emma Skovgaard","family":"Pedersen","sequence":"first","affiliation":[{"name":"Department of Clinical Epidemiology, Aarhus University Hospital Aarhus University  Aarhus N Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0158-7950","authenticated-orcid":false,"given":"Ellen M.","family":"Mikkelsen","sequence":"additional","affiliation":[{"name":"Department of Clinical Epidemiology, Aarhus University Hospital Aarhus University  Aarhus N Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4299-7040","authenticated-orcid":false,"given":"Henrik Toft","family":"S\u00f8rensen","sequence":"additional","affiliation":[{"name":"Department of Clinical Epidemiology, Aarhus University Hospital Aarhus University  Aarhus N Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7901-3928","authenticated-orcid":false,"given":"Elizabeth E.","family":"Hatch","sequence":"additional","affiliation":[{"name":"Boston University School of Public Health  Boston Massachusetts USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2138-3752","authenticated-orcid":false,"given":"Lauren A.","family":"Wise","sequence":"additional","affiliation":[{"name":"Boston University School of Public Health  Boston Massachusetts USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2398-1705","authenticated-orcid":false,"given":"Kenneth J.","family":"Rothman","sequence":"additional","affiliation":[{"name":"Boston University School of Public Health  Boston Massachusetts USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9932-3947","authenticated-orcid":false,"given":"Joseph B.","family":"Stanford","sequence":"additional","affiliation":[{"name":"Division of Public Health, Department of Family and Preventive Medicine University of Utah Spencer Fox Eccles School of Medicine  Salt Lake City Utah USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2827-0582","authenticated-orcid":false,"given":"Anne Sofie Dam","family":"Laursen","sequence":"additional","affiliation":[{"name":"Department of Clinical Epidemiology, Aarhus University Hospital Aarhus University  Aarhus N Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2024,8,7]]},"reference":[{"key":"e_1_2_12_2_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/dem046"},{"key":"e_1_2_12_3_1","doi-asserted-by":"publisher","DOI":"10.1185\/030079906X162863"},{"key":"e_1_2_12_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0029-7844(02)02382-7"},{"key":"e_1_2_12_5_1","doi-asserted-by":"publisher","DOI":"10.1002\/btm2.10058"},{"key":"e_1_2_12_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2015.01.031"},{"key":"e_1_2_12_7_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/deh173"},{"key":"e_1_2_12_8_1","doi-asserted-by":"publisher","DOI":"10.1179\/0024363912Z.0000000005"},{"key":"e_1_2_12_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejogrb.2005.07.024"},{"key":"e_1_2_12_10_1","doi-asserted-by":"publisher","DOI":"10.1111\/ppe.12642"},{"key":"e_1_2_12_11_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.2001.00194.x"},{"key":"e_1_2_12_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.rbmo.2020.09.005"},{"key":"e_1_2_12_13_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/deaa176"},{"key":"e_1_2_12_14_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/dem003"},{"key":"e_1_2_12_15_1","doi-asserted-by":"publisher","DOI":"10.3122\/jabfm.2016.04.160022"},{"key":"e_1_2_12_16_1","doi-asserted-by":"publisher","DOI":"10.1111\/jmwh.12216"},{"key":"e_1_2_12_17_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0000000000002784"},{"key":"e_1_2_12_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2019.06.036"},{"key":"e_1_2_12_19_1","doi-asserted-by":"publisher","DOI":"10.1185\/03007995.2012.681638"},{"key":"e_1_2_12_20_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-3016.2006.00765.x"},{"issue":"3","key":"e_1_2_12_21_1","article-title":"Timed intercourse for couples trying to conceive","author":"Manders M","year":"2015","journal-title":"Cochrane Database Syst Rev"},{"key":"e_1_2_12_22_1","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/dyn191"},{"key":"e_1_2_12_23_1","doi-asserted-by":"publisher","DOI":"10.1111\/ppe.12924"},{"key":"e_1_2_12_24_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/dead077"},{"key":"e_1_2_12_25_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.i4262"},{"key":"e_1_2_12_26_1","doi-asserted-by":"publisher","DOI":"10.1093\/oxfordjournals.aje.a115211"},{"key":"e_1_2_12_27_1","doi-asserted-by":"publisher","DOI":"10.1097\/EDE.0000000000001220"},{"key":"e_1_2_12_28_1","doi-asserted-by":"publisher","DOI":"10.6000\/1929-6029.2015.04.03.7"},{"key":"e_1_2_12_29_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.b2393"},{"key":"e_1_2_12_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jclinepi.2021.01.008"},{"key":"e_1_2_12_31_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jclinepi.2009.12.008"},{"key":"e_1_2_12_32_1","doi-asserted-by":"publisher","DOI":"10.1097\/EDE.0000000000000400"},{"key":"e_1_2_12_33_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/det023"},{"key":"e_1_2_12_34_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ypmed.2008.02.001"},{"key":"e_1_2_12_35_1","doi-asserted-by":"publisher","DOI":"10.1093\/ajcn\/72.2.541S"},{"key":"e_1_2_12_36_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/dey372"},{"key":"e_1_2_12_37_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2012.02.025"},{"key":"e_1_2_12_38_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2016.04.011"},{"key":"e_1_2_12_39_1","doi-asserted-by":"publisher","DOI":"10.1038\/ejcn.2015.94"},{"key":"e_1_2_12_40_1","doi-asserted-by":"publisher","DOI":"10.1097\/EDE.0000000000000916"},{"key":"e_1_2_12_41_1","doi-asserted-by":"publisher","DOI":"10.1089\/jwh.2021.0026"},{"key":"e_1_2_12_42_1","doi-asserted-by":"publisher","DOI":"10.1097\/00006250-200306000-00025"},{"key":"e_1_2_12_43_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2013.06.002"},{"key":"e_1_2_12_44_1","doi-asserted-by":"publisher","DOI":"10.1111\/ppe.12141"},{"issue":"2","key":"e_1_2_12_45_1","first-page":"152","article-title":"Natural family planning III. Intermenstrual symptoms and estimated time of ovulation","volume":"58","author":"Hilgers TW","year":"1981","journal-title":"Obstet Gynecol"},{"key":"e_1_2_12_46_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.321.7271.1259"},{"key":"e_1_2_12_47_1","doi-asserted-by":"publisher","DOI":"10.1111\/ppe.12644"},{"key":"e_1_2_12_48_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41746-019-0152-7"}],"container-title":["Paediatric and Perinatal Epidemiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/ppe.13108","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,11,28]],"date-time":"2024-11-28T13:10:47Z","timestamp":1732799447000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/ppe.13108"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,7]]},"references-count":47,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2024,11]]}},"alternative-id":["10.1111\/ppe.13108"],"URL":"https:\/\/doi.org\/10.1111\/ppe.13108","archive":["Portico"],"relation":{},"ISSN":["0269-5022","1365-3016"],"issn-type":[{"type":"print","value":"0269-5022"},{"type":"electronic","value":"1365-3016"}],"subject":[],"published":{"date-parts":[[2024,8,7]]},"assertion":[{"value":"2024-02-22","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-07-07","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-08-07","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}