The position of transferred air bubbles after embryo transfer is related to pregnancy rate

ObjectiveThe possibility to visualize the transfer air bubbles is one of the main benefits of ultrasonographic-guided embryo transfer. The objective of this study was to analyze the relation between the position of the air bubbles and pregnancy rates.DesignProspective data-analysis.SettingUniversity fertility clinic.Patient(s)IVF and intracytoplasmic sperm injection patients.Intervention(s)Transabdominal ultrasonographic guidance at embryo transfer.Main Outcome Measure(s)Pregnancy rate, length endometrial plate, distance catheter to fundus, distance air bubbles to fundus.Result(s)Analysis of 367 consecutive ultrasonographic-guided embryo transfers following IVF or intracytoplasmic sperm injection treatment. Both absolute and relative position of the air bubbles were significantly closer to the fundus in patients who became pregnant compared with patients who did not become pregnant. When the relative position of the air bubbles was in the fundal half of the endometrial plate pregnancy rates were significantly higher compared with the lower half of the endometrial plate, 43.0% and 24.4%, respectively, P=.002. Multiple regression analysis revealed the relative position as an independently associated determinant for pregnancy.Conclusion(s)The position of the air bubbles after embryo transfer is related to pregnancy rate; the highest pregnancy rates are found when the air bubbles end up closer to the fundus.