Evaluation of the Relationship Between Air Bubbles Depth and Pregnancy Rate in ICSI Cycles

All ET will be performed on day 3 after oocyte retrieval at the blastocyst stage by one operator under trans-abdominal US guidance performed by one physician, without any anesthesia or sedation with moderate bladder filling. Two embryos will be transferred using the same type of catheter which is Labotect embryo transfer catheter. It's a semirigid catheter that's less likely to induce endometrial trauma and uterine contractions.

The tip of the inner catheter will be placed approximately 1.5-2 cm from the fundal endometrial surface.The distance between the fundal endometrial surface and air bubbles will be measured and categorized as:

• Group 1: air bubbles depth <10 mm.
• Group 2: air bubbles depth >10 mm. The primary outcome will be biochemical pregnancy rate based on serum quantitative beta-hCG level at 14 days after ET. Secondary outcome will be clinical pregnancy rate using trans-vaginal US examination at 6 - 8 weeks of amenorrhea to detect the presence of fetal sac & pulsation.