Don't expect designer babies any time soon — but a major new ethics report leaves open the possibility of one day altering human heredity to fight genetic diseases, with stringent oversight, using new tools that precisely edit genes inside living cells. What's called genome editing already is transforming biological research, and being used to develop treatments for patients struggling with a range of diseases. The science is nowhere near ready for a huge next step that raises ethical questions — altering sperm, eggs or embryos so that babies don't inherit a disease that runs in the family, says a report from the National Academy of Sciences and National Academy of Medicine. But if scientists learn how to safely pass alterations of the genetic code to future generations, the panel said "germ line" editing could be attempted under strict criteria, including that it targets a serious disease with no reasonable alternative and is conducted under rigorous oversight.

Survival rate for preemies improves

Survival rates for very early preterm infants have improved slightly, according to a study published in the New England Journal of Medicine. Those who survive are also somewhat less likely to suffer from neurodevelopmental impairments, the study found. Researchers gathered survival and neurodevelopmental impairment data for 4,000 extremely premature infants by analyzing records from a National Institutes of Health research network. The infants were born between 22 and 24 weeks of gestation, rather than after a normal 40-week pregnancy. Survival rates of such infants born between 2000 and 2011 rose from 30 to 36 percent. The percentage of preterm infants who did not develop neurological impairments increased from 16 to 20 percent.

Long-term opioid use may depend on doctor

Luck may play a role in determining who ends up taking prescription opioids long-term, according to a study that found a link between the prescribing habits of hospital emergency room doctors and extended use of narcotic painkillers. People seen by an emergency room physician who tends to prescribe opioids frequently are about 30 percent more likely to take them for at least six more months over the ensuing year, according to the study by researchers at the Harvard T.H. Chan School of Public Health. The study also found a remarkable difference in opioid prescribing habits by doctors in the very same emergency rooms: "High-intensity prescribers" doled out narcotics during 24.1 percent of patient visits, on average, while "low-intensity prescribers" called for them only 7.3 percent of the time. In addition, patients who received a large dose of opioids at their initial visit were more likely to end up as long-term users.

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