Study Finds Way to Pick Healthiest Embryos

WASHINGTON (Reuters), December 2000

Scientists said on Wednesday they may have found a good way to identify the healthiest embryos for use in making test-tube babies – and discovered some basic biology in the process.

Little structures called microtubules in the egg cell may be key, infertility specialist Dr. Sam Alexander of Colorado Reproductive Endocrinology and colleagues at the University of Colorado report.

Writing in the December, 2000 issue of the journal Human Reproduction, Alexander and colleagues said the microtubules transport genetic material called mitochondrial DNA, which is found in eggs.

Embryos with symmetrical microtubules seemed to be more likely to survive attempts at in-vitro fertilization (IVF), they found.

“I believe the take-home message is that these findings may help us determine the embryo quality at an earlier stage,” Alexander said in a statement.

“We feel that using methods to judge embryo quality in the first three days of culture is a much more sensible and intelligent approach than the five-day, survival of the fittest, embryo approach.”

Biology professor Jonathan Van Blerkom of the University of Colorado, who worked on the study, said if the microtubule arrays in the egg cell do not mirror each other at the very first division of the cell, half of the tiny embyo, known technically as a blastomere, may not have enough of the structures.

“Eventually there may not be enough mitochondria in the blastomeres to produce a healthy embryo,” he said.

When a couple seeks to have a baby through IVF, doctors create many embryos in a laboratory dish, and then try to select the healthiest ones to implant in the mother’s womb.

Screening for microtubules might offer a good way to do this check, the researchers suggested.