How long does an "egg" remain in the tube before it is transferred to a uterus? My wife and I are looking into ivf. Before seeing a doctor, we are trying to gather as much information as possible, and this site has been a great source over the past couple

When . When ovulation occurs, the fallopian tube actually moves over and picks up the egg. It is then transported down the tube by little projections called cilia. The sperm survive in the tube for approximately 6 days. While there, they are attached to the cells of the lining of the fallopian tube and periodically attach and detach from these cells waiting for the egg. Fertilization normally takes place in the fallopian tube as soon as a sperm attaches to the shell of the egg. The fertilized egg then goes on to develop in the tube for about 5 days. It enters the uterus 5 or 6 days after ovulation. This process has lead people to conclude that it is important for fertilization and early embryo development to happen in the fallopian tube. Many studies have been done to see if sperm and egg or embryos should be transferred into the tube rather than the uterus. Most of them did not show a benefit to doing this. As we became better at growing embryos longer in the lab, the ability to select better embryos has outweighed any theoretical advantage to a tubal transfer. Embryos are now routinely cultured 5 or 6 days in the lab and transferred to the uterus. This is called "blastocyst transfer” proponents of this technique claim that pregnancy rates are better with this technique because the embryos are placed in the uterus at the time that they normally enter the uterus. There is still some controversy surrounding this claim, but more and more centers are moving to blastocyst culture because it allows us to select better embryos from a group of embryos for transfer. I hope this helps and good luck!