Body & Brain
Hockey concussions take progressively longer to heal, plus rotavirus vaccines and declining stillbirths in this week's news.
By Science News
Recovery time longer with each concussion
Each successive concussion suffered by a professional hockey player takes slightly longer to overcome than the last, a study released online April 18 in the Canadian Medical Association Journal shows. The researchers, including National Hockey League team physicians, analyzed all 559 concussions reported in seven NHL seasons spanning 1997 to 2004, an average of 80 per season. In nearly one-third of cases, a player missed more than 10 days of play. First-time concussions required an average of six days to return to the ice, while subsequent concussions added about one extra day for each. But four players who suffered their fifth concussions needed 12 to 106 days to recover. The most common symptom was headache. —Nathan Seppa
Rotavirus vaccine cuts death rate
Diarrhea-related deaths among children age 2 or younger dropped by 6 to 45 percent in the three years after Brazil started giving the rotavirus vaccine to infants. Likewise, hospital admissions for diarrheal illness among children 2 or under fell by 7 to 34 percent, an international team of scientists reports in the April PLoS Medicine. The program assigned babies to get the vaccine at less than 15 weeks of age. The researchers estimate the program has resulted in 1,500 fewer deaths and 130,000 fewer hospitalizations since it started in 2006. —Nathan Seppa
Stillbirths declining worldwide
The worldwide rate of stillbirths has fallen from 22 per 1,000 pregnancies to 19 per 1,000 over the last 15 years, two studies appearing online April 13 in Lancet show. Stillbirth rates remain highest in South Asia and sub-Saharan Africa. Although high-income regions such as the United States and Western Europe typically have stillbirth rates below 5 per 1,000 pregnancies, these nations have shown little improvement in the past decade. Fetal risks of stillbirth include small size and placental rupture, two international research teams found. Risks in the mother include obesity, smoking, advanced age, pre-existing diabetes and high blood pressure. The researchers note that many of the risks are partly or entirely avoidable. —Nathan Seppa