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CC was applied in a dosage of 25mcg per day, starting on cycle day 7 until ovulation trigger day. Primary outcomes were clinical pregnancy rate, defined as amniotic sac visible in ultrasound, and live birth rate per transferred embryo. Miscarriage rate calculated as amniotic sac not ending in a live birth was secondary outcome. A modified mixed-effect Poisson regression model was applied, and adjustments were made for female age, parity, type and cause of infertility. Additionally, stratification by parity and age was performed.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Results<\/jats:title>\n                <jats:p>Four hundred and ninety-nine couples underwent a total of 1042 IVF cycles, 453 being NC-IVF and 589 being CC-NC-IVF cycles. Baseline characteristics of both groups did not differ. Addition of CC did neither decrease clinical pregnancy rate (aRR 0.86; 95% CI 0.67\u20131.12) nor live birth rate per transferred embryo (aRR 0.84; 95% CI 0.62\u20131.13) in comparison with NC-IVF. Miscarriage rate did not differ between CC-NC-IVF and NC-IVF (aRR 0.95; 95% CI 0.57\u20131.57).<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusion<\/jats:title>\n                <jats:p>Low-dose CC does not reduce pregnancy or live birth rate per transferred embryo. It can be used in infertility treatment without negatively affecting the endometrium and implantation.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1007\/s00404-022-06878-6","type":"journal-article","created":{"date-parts":[[2022,12,16]],"date-time":"2022-12-16T11:02:56Z","timestamp":1671188576000},"page":"1073-1081","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Low-dose clomiphene citrate does not reduce implantation and live birth rates in otherwise unstimulated modified natural cycle IVF\u2014retrospective cohort study"],"prefix":"10.1007","volume":"307","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2727-7486","authenticated-orcid":false,"given":"Flavia","family":"Gr\u00e4del","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4303-2734","authenticated-orcid":false,"given":"Michael","family":"von Wolff","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7558-1327","authenticated-orcid":false,"given":"Alexandra Sabrina","family":"Kohl Schwartz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1483-5020","authenticated-orcid":false,"given":"Vera Ruth","family":"Mitter","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2022,12,16]]},"reference":[{"key":"6878_CR1","doi-asserted-by":"publisher","DOI":"10.1210\/jcem-61-2-265","author":"JF Kerin","year":"1985","unstructured":"Kerin JF, Liu JH, Phillipou G, Yen SSC (1985) Evidence for a hypothalamic site of action of clomiphene citrate in women. 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Michael von Wolff received a research grant from IBSA Institut Biochimique, Lugano, Switzerland. Alexandra S Kohl Schwartz has received funding for the set-up of the Bern IVF cohort from Merck, Switzerland SA. Vera R Mitter received congress and travel support from Theramex.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Conflict of interest"}},{"value":"This study was performed in line with the principles of the Declaration of Helsinki. The Ethics Commission of the Canton of Bern approved the study on February 26, 2020 (BASEC 2020-00021).","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethical approval"}},{"value":"Not applicable. This study is a further use of health-related personal data and the need for informed consent was waived by the Ethics Commission of the Canton of Bern.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent to participate"}},{"value":"Not applicable.","order":5,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent to publish"}}]}}