title: Reporting of embryo transfer methods in IVF research: a cross-sectional study.
abstract: The reporting of embryo transfer methods in IVF research was assessed through a cross-sectional analysis of randomized controlled trials (RCTs) published between 2010 and 2011. A systematic search identified 325 abstracts; 122 RCTs were included in the study. Embryo transfer methods were described in 42 out of 122 articles (34%). Catheters (32/42 [76%]) or ultrasound guidance (31/42 [74%]) were most frequently mentioned. Performer 'blinding' (12%) or technique standardization (7%) were seldom reported. The description of embryo transfer methods was significantly more common in trials published by journals with lower impact factor (less than 3, 39.6%; 3 or greater, 21.5%; P = 0.037). Embryo transfer methods were reported more often in trials with pregnancy as the main end-point (33% versus 16%) or with positive outcomes (37.8% versus 25.0%), albeit not significantly. Multivariate logistic regression confirmed that RCTs published in higher impact factor journals are less likely to describe embryo transfer methods (OR 0.371; 95% CI 0.143 to 0.964). Registered trials, trials conducted in an academic setting, multi-centric studies or full-length articles were not positively associated with embryo transfer methods reporting rate. Recent reports of randomized IVF trials rarely describe embryo transfer methods. The under-reporting of research methods might compromise reproducibility and suitability for meta-analysis.
authors.affiliation: Karolinska Institutet, LIME/NASP - C7, 17 177 Stockholm, Sweden; Res Medica Sweden, Gynaecology & Reproductive Medicine, 752 24 Uppsala, Sweden. Electronic address: gambadauro@gmail.com.
authors.forename: Pietro
authors.initials: P
authors.lastname: Gambadauro
authors.affiliation: Bart's Health NHS Trust, Obstetrics and Gynaecology, The Royal London Hospital, E1 1BB London, UK; Katherine Twining Network, Queen Mary University of London, E1 2AB London, UK.
authors.forename: Ramesan
authors.initials: R
authors.lastname: Navaratnarajah
mesh_terms: D003430:Cross-Sectional Studies; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007246:Infertility / Q000628:therapy; D055811:Journal Impact Factor; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011642:Publications; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012107:Research Design; D012306:Risk; D014463:Ultrasonography
keywords: embryo transfer; in-vitro fertilization; randomized controlled trials; reproducibility of research; research methods; risk of bias