IVF dangers may be overblown

INFERTILITY
We are often willing to blame technology for our medical misfortunes, but in the case of infertility, the body itself may be the source of trouble. Assisted fertilization technologies that join an egg with sperm in a laboratory, come with extra risks - including a 31 percent increased risk of infant death and a 26 percent chance of the infant being small for gestational age. Now, a study led by Dr. Liv Bente Romundstad from St. Olavs University Hospital in Norway concludes that the increased risk may be due to the underlying causes of infertility rather than the in vitro fertilization procedure itself. She compared birth weight, size, gestation age, and infant death rate in women who had conceived one child spontaneously and another with IVF assistance with those of women who only conceived using IVF. The findings suggests that since women who conceived both ways had infants with similar good health each time, then the increased risks associated with IVF may be due to factors other than the technological risks. BOTTOM LINE: "The adverse outcomes [of IVF] seem to be caused by factors leading to or related to infertility rather than the technology," said Romundstad. CAUTIONS: On average the women who conceived with assisted fertilization were older than those who did not use it, so perhaps age, rather than infertility, was the issue. WHAT'S NEXT: The authors plan to look at the prevalence of birth deformities in infants conceived with assisted fertilization technologies compared to those who were spontaneously conceived. WHERE TO FIND IT: The Lancet, August 2.
DINA FINE MARON

AGING

The brain's hippocampus - named for the Greek word for seahorse, which it resembles - has an important job. During sleep, it acts like a video recorder, replaying events that occurred during the day and transforming them into more solid memories. As we age, however, scientists believe that the hippocampus might find it increasingly difficult to fulfill its duties as the memory maker. To test whether this is the case, principal investigator Carol Barnes and colleagues from the Evelyn F. McKnight Brain Institute at the University of Arizona examined the hippocampi of rats of different ages. First, the researchers put both young rats and older rats into a maze filled with tiny rewards of food. While the rats sniffed out the prize, researchers recorded the pattern of signals fired in their hippocampi. Later on, when the animals went to sleep, the researchers found that brain of the younger rats replayed the same sequence of events again, as though locking the memory of the maze into place, while the brains of the older rats didn't replay the scene. When the rats awoke, the younger ones got to the food more efficiently than the aging rats. BOTTOM LINE: Sleep may not help solidify memories in older people as well as it does in younger ones. CAUTIONS: This work is done in rats, so more work needs to be done to apply these findings to human behavior. WHAT'S NEXT: Researchers are trying to figure whether sleep patterns that change with age - such as the natural loss of REM sleep - might make it harder to form memories as we grow older. WHERE TO FIND IT: The Journal of Neuroscience, July 30. SUSHRUT JANGI