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Embryo test tube liquid holds clues to IVF success. An experimental test may help fertility specialists improve the odds of successful pregnancies and live births after vitro fertilization (IVF), researchers said. For IVF, eggs are fertilized in test tubes and later transferred into the womb. In the United States, only 20% to 40% of IVF procedures result in live births, in part because it’s very hard to know which lab-grown embryos are most likely to result in successful pregnancy, the researchers said. A separate study of IVF costs published in November found the average price of one cycle in the United States ranges from $12,000 to $17,000, increasing to $25,000 if medications are needed. Only 14 states mandate IVF to be included in insurance plans. The new method identifies higher-quality embryos by detecting small particles of genetic material in the test-tube liquid in which they are grown, according to a report published in Cell Genomics on Wednesday. Currently, doctors select embryos for IVF based on their appearance, or by taking some cells from the embryo to look at genetic makeup, both of which have limitations, study leader Dr. Irene Su at UC San Diego School of Medicine said in a statement. Instead of relying on visual characteristics or biopsies of embryos, the new approach analyzes RNA molecules from the embryos in the medium used to grow them. While most RNA stays inside the embryos' cells, some molecules, called exRNAs, are released into the liquid the embryos are growing in, the researchers explained. By analyzing the culture media for embryos at different stages of development, the researchers identified exRNAs that correspond to genetic activity at each stage. They developed computer models that could identify normally-developing embryos, without genetic defects, that were likely to be of higher quality. An editorial published with the study said the new test yields “a wealth of... information associated with the embryonic development cycle.” The researchers still need to prove their test predicts actual pregnancy outcomes. “Unfortunately, IVF success still involves a big element of chance, but that’s something we’re hoping our research can change,” Dr. Irene Su said. |