{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T03:35:21Z","timestamp":1791862521572,"version":"4.3.4"},"reference-count":22,"publisher":"Oxford University Press (OUP)","issue":"3","license":[{"start":{"date-parts":[[2024,1,24]],"date-time":"2024-01-24T00:00:00Z","timestamp":1706054400000},"content-version":"vor","delay-in-days":1,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2024,3,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:sec>\n                  <jats:title>STUDY QUESTION<\/jats:title>\n                  <jats:p>Can women with pregnancy of unknown location (PUL) following in vitro fertilization (IVF) be risk-stratified regarding the subsequent need for medical intervention, based on their demographic characteristics and the results of serum biochemistry at the initial visit?<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>SUMMARY ANSWER<\/jats:title>\n                  <jats:p>The ratio of serum hCG to number of days from conception (hCG\/C) or the initial serum hCG level at \u22655 weeks\u2019 gestation could be used to estimate the risk of women presenting with PUL following IVF and needing medical intervention during their follow-up.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>WHAT IS KNOWN ALREADY<\/jats:title>\n                  <jats:p>In women with uncertain conception dates presenting with PUL, a single serum hCG measurement cannot be used to predict the final pregnancy outcomes, thus, serial levels are mandatory to establish a correct diagnosis. Serum progesterone levels can help to risk-stratify women at their initial visit but are not accurate in those taking progesterone supplementation, such as women pregnant following IVF.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>STUDY DESIGN, SIZE, DURATION<\/jats:title>\n                  <jats:p>This was a retrospective study carried out at two specialist early pregnancy assessment units between May 2008 and January 2021. A total of 224 women met the criteria for inclusion, but 14 women did not complete the follow-up and were excluded from the study.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>PARTICIPANTS\/MATERIALS, SETTING, METHODS<\/jats:title>\n                  <jats:p>We selected women who had an IVF pregnancy and presented with PUL at \u22655 weeks\u2019 gestation.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>MAIN RESULTS AND THE ROLE OF CHANCE<\/jats:title>\n                  <jats:p>A total of 30\/210 (14.0%, 95% CI 9.9\u201319.8) women initially diagnosed with PUL required surgical intervention. The hCG\/C was significantly higher in the group of women requiring an intervention compared to those who did not (P\u2009=\u20090.003), with an odds ratio of 3.65 (95% CI 1.49\u20138.89, P\u2009=\u20090.004). A hCG\/C &amp;lt;4.0 was associated with a 1.9% risk of intervention, which accounted for 25.7% of the study population. A similar result was obtained by substituting hCG\/C &amp;lt;4.0 with an initial hCG level &amp;lt;100 IU\/l, which was associated with 2.0% risk of intervention, and accounted for 23.8% of the study population (P\u2009&amp;gt;\u20090.05)<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>LIMITATIONS, REASONS FOR CAUTION<\/jats:title>\n                  <jats:p>A limitation of our study is that it is retrospective in nature, and as such, we were reliant on existing data.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>WIDER IMPLICATIONS OF THE FINDINGS<\/jats:title>\n                  <jats:p>A previous study in women with PUL after spontaneous conception found that a 2% intervention rate was considered low enough to eliminate the need for close follow-up and serial blood tests. Using the same 2% cut-off, a quarter of women with PUL after IVF could also avoid attending for further visits and investigations.<\/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 required for this study. No conflicts of interest are required to be declared.<\/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\/deae002","type":"journal-article","created":{"date-parts":[[2024,1,24]],"date-time":"2024-01-24T15:02:09Z","timestamp":1706108529000},"page":"509-515","source":"Crossref","is-referenced-by-count":8,"title":["Development of a single-visit protocol for the management of pregnancy of unknown location following <i>in vitro<\/i> fertilization: a retrospective study"],"prefix":"10.1093","volume":"39","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0391-4989","authenticated-orcid":false,"given":"W M","family":"Dooley","sequence":"first","affiliation":[{"name":"Faculty of Population Health Sciences, Institute for Women\u2019s Health, University College Hospital , London, 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