For the thousands of hopeful couples who try in vitro fertilization each year, the procedure's 85% failure rate can be emotionally and financially devastating. Although it's fairly easy to retrieve and fertilize an egg, problems begin once it's placed in the womb. There, the so-called conceptus often fails to attach to the uterine wall. Now, obstetrician Ronald F. Feinberg and pathologist Harvey J. Kliman, both of the University of Pennsylvania, have discovered a "glue" protein that may be the missing link.
The doctors found the protein, which is produced by trophoblasts, the main cell that makes up the placenta, in the junction between the uterus and placenta in pregnant women. They believe that the protein facilitates the attachment of the fertilized egg to the uterus--a process known as implantation that is key to the success of in vitro fertilization.
The researchers are now striving to isolate the glue gene from trophoblasts and produce a recombinant protein for use as a drug. They are working with Ares-Serono, a Geneva-based leader in fertility products, to develop such a product.