{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,26]],"date-time":"2026-10-26T06:12:49Z","timestamp":1792995169891,"version":"4.5.0"},"reference-count":31,"publisher":"Oxford University Press (OUP)","issue":"3","license":[{"start":{"date-parts":[[2020,11,23]],"date-time":"2020-11-23T00:00:00Z","timestamp":1606089600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2021,2,18]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:sec>\n                  <jats:title>STUDY QUESTION<\/jats:title>\n                  <jats:p>Can we use prediction modelling to estimate the impact of coronavirus disease 2019 (COVID 19) related delay in starting IVF or ICSI in different groups of women?<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>SUMMARY ANSWER<\/jats:title>\n                  <jats:p>Yes, using a combination of three different models we can predict the impact of delaying access to treatment by 6 and 12\u2009months on the probability of conception leading to live birth in women of different age groups with different categories of infertility.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>WHAT IS KNOWN ALREADY<\/jats:title>\n                  <jats:p>Increased age and duration of infertility can prejudice the chances of success following IVF, but couples with unexplained infertility have a chance of conceiving naturally without treatment whilst waiting for IVF. The worldwide suspension of IVF could lead to worse outcomes in couples awaiting treatment, but it is unclear to what extent this could affect individual couples based on age and cause of infertility.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>STUDY DESIGN, SIZE, DURATION<\/jats:title>\n                  <jats:p>A population-based cohort study based on national data from all licensed clinics in the UK obtained from the Human Fertilisation and Embryology Authority Register. Linked data from 9589 women who underwent their first IVF or ICSI treatment in 2017 and consented to the use of their data for research were used to predict livebirth.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>PARTICIPANTS\/MATERIALS, SETTING, METHODS<\/jats:title>\n                  <jats:p>Three prediction models were used to estimate the chances of livebirth associated with immediate treatment versus a delay of 6 and 12\u2009months in couples about to embark on IVF or ICSI.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>MAIN RESULTS AND THE ROLE OF CHANCE<\/jats:title>\n                  <jats:p>We estimated that a 6-month delay would reduce IVF livebirths by 0.4%, 2.4%, 5.6%, 9.5% and 11.8% in women aged &amp;lt;30, 30\u201335, 36\u201337, 38\u201339 and 40\u201342\u2009years, respectively, while corresponding values associated with a delay of 12\u2009months were 0.9%, 4.9%, 11.9%, 18.8% and 22.4%, respectively. In women with known causes of infertility, worst case (best case) predicted chances of livebirth after a delay of 6\u2009months followed by one complete IVF cycle in women aged &amp;lt;30, 30\u201335, 36\u201337, 38\u201339 and 40\u201342\u2009years varied between 31.6% (35.0%), 29.0% (31.6%), 23.1% (25.2%), 17.2% (19.4%) and 10.3% (12.3%) for tubal infertility and 34.3% (39.2%), 31.6% (35.3%) 25.2% (28.5%) 18.3% (21.3%) and 11.3% (14.1%) for male factor infertility. The corresponding values in those treated immediately were 31.7%, 29.8%, 24.5%, 19.0% and 11.7% for tubal factor and 34.4%, 32.4%, 26.7%, 20.2% and 12.8% in male factor infertility. In women with unexplained infertility the predicted chances of livebirth after a delay of 6\u2009months followed by one complete IVF cycle were 41.0%, 36.6%, 29.4%, 22.4% and 15.1% in women aged &amp;lt;30, 30\u201335, 36\u201337, 38\u201339 and 40\u201342\u2009years, respectively, compared to 34.9%, 32.5%, 26.9%, 20.7% and 13.2% in similar groups of women treated without any delay. The additional waiting period, which provided more time for spontaneous conception, was predicted to increase the relative number of babies born by 17.5%, 12.6%, 9.1%, 8.4% and 13.8%, in women aged &amp;lt;30, 30\u201335, 36\u201337, 38\u201339 and 40\u201342\u2009years, respectively. A 12-month delay showed a similar pattern in all subgroups.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>LIMITATIONS, REASONS FOR CAUTION<\/jats:title>\n                  <jats:p>Major sources of uncertainty include the use of prediction models generated in different populations and the need for a number of assumptions. Although the models are validated and the bases for the assumptions are robust, it is impossible to eliminate the possibility of imprecision in our predictions. Therefore, our predicted live birth rates need to be validated in prospective studies to confirm their accuracy.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>WIDER IMPLICATIONS OF THE FINDINGS<\/jats:title>\n                  <jats:p>A delay in starting IVF reduces success rates in all couples. For the first time, we have shown that while this results in fewer babies in older women and those with a known cause of infertility, it has a less detrimental effect on couples with unexplained infertility, some of whom conceive naturally whilst waiting for treatment. Post-COVID 19, clinics planning a phased return to normal clinical services should prioritize older women and those with a known cause of infertility.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>STUDY FUNDING\/COMPETING INTEREST(S)<\/jats:title>\n                  <jats:p>No external funding was received for this study. B.W.M. is supported by an NHMRC Practitioner Fellowship (GNT1082548) and reports consultancy work for ObsEva, Merck, Merck KGaA, Guerbet and iGenomics. S.B. is Editor-in-Chief of Human Reproduction Open. None of the other authors declare any conflicts of interest.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>TRIAL REGISTRATION NUMBER<\/jats:title>\n                  <jats:p>N\/A.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1093\/humrep\/deaa339","type":"journal-article","created":{"date-parts":[[2020,11,20]],"date-time":"2020-11-20T20:41:39Z","timestamp":1605904899000},"page":"666-675","source":"Crossref","is-referenced-by-count":31,"title":["Prioritizing IVF treatment in the post-COVID 19 era: a predictive modelling study based on UK national data"],"prefix":"10.1093","volume":"36","author":[{"given":"Siladitya","family":"Bhattacharya","sequence":"first","affiliation":[{"name":"School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abha","family":"Maheshwari","sequence":"additional","affiliation":[{"name":"School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariam Begum","family":"Ratna","sequence":"additional","affiliation":[{"name":"School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rik","family":"van Eekelen","sequence":"additional","affiliation":[{"name":"Centre for Reproductive Medicine, Academic Medical Centre University of Amsterdam, Amsterdam, Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ben Willem","family":"Mol","sequence":"additional","affiliation":[{"name":"School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, UK"},{"name":"Department of Obstetrics & Gynaecology, Monash University, Monash Medical Centre, Clayton, VIC, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David J","family":"McLernon","sequence":"additional","affiliation":[{"name":"School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2020,11,23]]},"reference":[{"key":"2021021818575167200_deaa339-B1","year":"2020"},{"key":"2021021818575167200_deaa339-B2","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1186\/s12958-020-00605-z","article-title":"COVID-19 and assisted reproductive technology services: repercussions for patients and proposal for individualized clinical management","volume":"18","author":"Alviggi","year":"2020","journal-title":"Reprod Biol Endocrinol"},{"key":"2021021818575167200_deaa339-B3","doi-asserted-by":"crossref","first-page":"1757","DOI":"10.1093\/humrep\/deh818","article-title":"Resolving methodological and clinical issues in the design of efficacy trials in assisted reproductive technologies: a mini-review","volume":"20","author":"Arce","year":"2005","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B4","doi-asserted-by":"crossref","first-page":"660","DOI":"10.1093\/humupd\/dmx021","article-title":"The diagnosis of male infertility: an analysis of the evidence to support the development of global WHO guidance-challenges and future research opportunities","volume":"23","author":"Barratt","year":"2017","journal-title":"Hum Reprod Update"},{"key":"2021021818575167200_deaa339-B6","doi-asserted-by":"crossref","first-page":"a716","DOI":"10.1136\/bmj.a716","article-title":"Clomifene citrate or unstimulated intrauterine insemination compared with expectant management for unexplained infertility: pragmatic randomised controlled trial","volume":"337","author":"Bhattacharya","year":"2008","journal-title":"BMJ"},{"key":"2021021818575167200_deaa339-B7","doi-asserted-by":"crossref","first-page":"1203","DOI":"10.1016\/j.fertnstert.2014.03.047","article-title":"Ongoing pregnancy qualifies best as the primary outcome measure of choice in trials in reproductive medicine: an opinion paper","volume":"101","author":"Braakhekke","year":"2014","journal-title":"Fertil Steril"},{"key":"2021021818575167200_deaa339-B8","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1093\/humrep\/deq349","article-title":"Unexplained infertility: overall ongoing pregnancy rate and mode of conception","volume":"26","author":"Brandes","year":"2011","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B10","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/S0015-0282(16)57650-X","article-title":"The prognosis for live birth among untreated infertile couples","volume":"64","author":"Collins","year":"1995","journal-title":"Fertil Steril"},{"key":"2021021818575167200_deaa339-B11","doi-asserted-by":"crossref","first-page":"999","DOI":"10.1093\/humrep\/dex018","article-title":"Cost-effectiveness of \u2018immediate IVF\u2019 versus \u2018delayed IVF\u2019: a prospective study","volume":"32","author":"Eijkemans","year":"2017","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B12","doi-asserted-by":"crossref","first-page":"1627","DOI":"10.1093\/humrep\/den132","article-title":"Pregnancy chances on an IVF\/ICSI waiting list: a national prospective cohort study","volume":"23","author":"Eijkemans","year":"2008","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B13","doi-asserted-by":"crossref","first-page":"1470","DOI":"10.1093\/humrep\/dez099","article-title":"Treatment-independent live birth after in-vitro fertilisation: a retrospective cohort study of 2,133 women","volume":"34","author":"El Mokhallalati","year":"2019","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B14","author":"ESHRE. European Society for Human Reproduction and Embryology","year":"2020"},{"key":"2021021818575167200_deaa339-B15","author":"HFEA","year":"2020"},{"key":"2021021818575167200_deaa339-B16","author":"HFEA","year":"2020"},{"key":"2021021818575167200_deaa339-B17","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1093\/humrep\/deu262","article-title":"Overtreatment in couples with unexplained infertility","volume":"30","author":"Kersten","year":"2015","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B18","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1016\/S0140-6736(11)61267-1","article-title":"Effect of age on decisions about the numbers of embryos to transfer in assisted conception: a prospective study","volume":"379","author":"Lawlor","year":"2012","journal-title":"Lancet"},{"key":"2021021818575167200_deaa339-B19","doi-asserted-by":"crossref","first-page":"1126","DOI":"10.1093\/humrep\/dez049","article-title":"Predicting the chances of having a baby with or without treatment at different time points in couples with unexplained subfertility","volume":"34","author":"McLernon","year":"2019","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B20","doi-asserted-by":"crossref","first-page":"i5735","DOI":"10.1136\/bmj.i5735","article-title":"Predicting the chances of a live birth after one or more complete cycles of in vitro fertilisation: population-based study of linked cycle data from 113\u2009873 women","volume":"355","author":"McLernon","year":"2016","journal-title":"BMJ"},{"key":"2021021818575167200_deaa339-B21","author":"NICE. National Collaborating Centre for Women\u2019s and Children\u2019s Health","year":"2013"},{"key":"2021021818575167200_deaa339-B22","first-page":"CD003357","article-title":"In vitro fertilisation for unexplained subfertility","volume":"2015","author":"Pandian","year":"2015","journal-title":"Cochrane Database Syst Rev"},{"key":"2021021818575167200_deaa339-B23","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1093\/humrep\/dez258","article-title":"A systematic review of the quality of clinical prediction models in in vitro fertilisation","volume":"35","author":"Ratna","year":"2020","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B24","author":"RCOG","year":"2020"},{"key":"2021021818575167200_deaa339-B25","doi-asserted-by":"crossref","DOI":"10.1093\/humrep\/deaa137","article-title":"Delay in IVF treatment up to 180 days does not affect pregnancy outcomes in women with diminished ovarian reserve","author":"Romanski","year":"2020","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B26","doi-asserted-by":"crossref","first-page":"1402","DOI":"10.1016\/S0140-6736(96)05291-9","article-title":"Factors that affect outcome of in-vitro fertilisation treatment","volume":"348","author":"Templeton","year":"1996","journal-title":"Lancet"},{"key":"2021021818575167200_deaa339-B27","doi-asserted-by":"crossref","first-page":"1784","DOI":"10.1093\/humrep\/der123","article-title":"Tailored expectant management: risk factors for non-adherence","volume":"26","author":"van den Boogaard","year":"2011","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B28","first-page":"2268","article-title":"External validation of a dynamic prediction model for repeated predictions of natural conception over time","volume":"33","author":"van Eekelen","year":"2018","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B29","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1093\/humrep\/dew309","article-title":"Natural conception: repeated predictions over time","volume":"32","author":"van Eekelen","year":"2017","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B30","doi-asserted-by":"crossref","first-page":"919","DOI":"10.1093\/humrep\/dey051","article-title":"Natural conception rates in couples with unexplained or mild male subfertility scheduled for fertility treatment: a secondary analysis of a randomized controlled trial","volume":"33","author":"van Eekelen","year":"2018","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B31","doi-asserted-by":"crossref","first-page":"1249","DOI":"10.1093\/humrep\/dez072","article-title":"McLernon DJ. IVF for unexplained subfertility; whom should we treat?","volume":"34","author":"van Eekelen","year":"2019","journal-title":"Hum Reprod"},{"key":"2021021818575167200_deaa339-B32","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1016\/j.jare.2013.05.002","article-title":"Prediction models in in vitro fertilization; where are we? A mini review","volume":"5","author":"van Loendersloot","year":"2014","journal-title":"J Adv Res"},{"key":"2021021818575167200_deaa339-B33","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1093\/humupd\/dmq015","article-title":"Predictive factors in in vitro fertilization (IVF): a systematic review and meta-analysis","volume":"16","author":"van Loendersloot","year":"2010","journal-title":"Hum Reprod Update"}],"container-title":["Human Reproduction"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/academic.oup.com\/humrep\/advance-article-pdf\/doi\/10.1093\/humrep\/deaa339\/35114035\/deaa339.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"http:\/\/academic.oup.com\/humrep\/article-pdf\/36\/3\/666\/36317968\/deaa339.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"http:\/\/academic.oup.com\/humrep\/article-pdf\/36\/3\/666\/36317968\/deaa339.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,2,21]],"date-time":"2021-02-21T01:33:32Z","timestamp":1613871212000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/humrep\/article\/36\/3\/666\/5998652"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,11,23]]},"references-count":31,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2020,11,23]]},"published-print":{"date-parts":[[2021,2,18]]}},"URL":"https:\/\/doi.org\/10.1093\/humrep\/deaa339","relation":{},"ISSN":["0268-1161","1460-2350"],"issn-type":[{"value":"0268-1161","type":"print"},{"value":"1460-2350","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2021,3,1]]},"published":{"date-parts":[[2020,11,23]]}}}