title: Risk of ectopic pregnancy following day-5 embryo transfer compared with day-3 transfer.
abstract: The incidence of ectopic pregnancy after IVF is increased approximately 2.5-5-fold compared with natural conceptions; however, the aetiology for this increased risk remains unclear. One proposed practice change to decrease the incidence of ectopic pregnancy is blastocyst embryo transfer on day 5 rather than cleavage-stage embryo transfer on day 3. A retrospective cohort study was conducted to compare the risk of ectopic pregnancy following fresh day-5 embryo transfer with day-3 embryo transfer among women who underwent IVF and achieved pregnancy from 1998 to 2011. There were 13,654 eligible pregnancies; 277 were ectopic. The incidence of ectopic pregnancy was 2.1% among day-3 pregnancies and 1.6% among day-5 pregnancies. The adjusted risk ratio for ectopic pregnancy from day-5 compared with day-3 transfer was 0.71 (95% confidence interval 0.46-1.10). Although this analysis included 13,654 cycles, with a two-sided significance level of 0.05, it had only 21.9% power to detect a difference between the low incidence of ectopic pregnancy among both day-3 and day-5 transfers. In conclusion, this study was not able to demonstrate a difference in the risk of ectopic pregnancy among day-3 compared with day-5 transfers.
authors: Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Kirstein 3, Boston, MA 02215, USA; Boston IVF, 130 Second Avenue, Waltham, MA 02451, USA; Department of Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA; Reproductive Medicine and Surgery Center of Virginia, 595 Martha Jefferson Drive, Suite 390, Charlottesville, VA 22911, USA.
authors: Laura P
authors: LP
authors: Smith
authors: Selwyn P
authors: SP
authors: Oskowitz
authors: Laura E
authors: LE
authors: Dodge
authors: Michele R
authors: MR
authors: Hacker
mesh_terms: D010064:Embryo Implantation; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D015994:Incidence; D016017:Odds Ratio; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000453:epidemiology*; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors
keywords: blastocyst; day-3 embryo transfer; day-5 embryo transfer; ectopic