After falling four years in a row, U.S. births may finally be leveling off.

The number of babies born last year — a little shy of 4 million — is only a few hundred less than the number in 2011, according to a government report released Friday.

Doctors declared Wednesday that a pair of formerly conjoined twins were healthy and happy after they were successfully separated in a marathon "nerve-wracking" operation in India by a team of 40 specialists.

The one-year-old girls from Nigeria, sporting matching bright pink dresses, sat patiently on their parents' laps as doctors explained the separation last month during an 18-hour operation at a New Delhi hospital.

A video game can help elderly people fight cognitive decline, scientists reported in the journal Nature on Wednesday.

The novel game shows the brain is more "plastic," or versatile, in healthy ageing people than thought, which opens up new paths for warding off mental decay, its inventors said.

A new software tool may help doctors eliminate mistakes when judging whether a spot that turns up on a smoker's lung scan is cancerous or not, researchers said Wednesday.

The clinical risk assessment method described in the New England Journal of Medicine helped correctly decide nine times out of 10 whether a spot or lesion was benign or malignant.

Big anti-smoking messages on the front of cigarette packets may help deter youngsters tempted by tobacco but have little effect when they are on the back of the pack, research has found.

Touching on a subject that has stirred controversy in countries where pro- and anti-tobacco lobbies are fighting over smoking controls, investigators looked at data from a large survey among British teenagers.

The use of illegal drugs among Americans in general is holding steady, but it's surging among middle-aged baby boomers, according to report released Wednesday.

The National Survey on Drug Use and Health indicated that 9.2 percent of Americans aged 12 and over, or 23.9 million, were current consumers of illicit substances.

Global health experts have warned against giving iron supplements in areas where malaria is rampant, but a study Tuesday found no rise in cases of the mosquito-borne disease among children who took iron.

However, hospital visits for severe diarrhea episodes were significantly higher among children in Ghana given extra iron, raising questions about its safety, experts said.

A follow-up probe into the use of circumcision to thwart the AIDS virus has confirmed that foreskin removal greatly reduces the risk of HIV infection for men.

So say a team led by French researcher Bertran Auvert, whose pioneering work, unveiled in 2006, helped unleash a circumcision campaign in AIDS-hit sub-Saharan Africa.

Almost 12 percent of adults in China had diabetes in 2010, with economic prosperity driving the disease to slightly higher proportions than in the United States, researchers said Tuesday.

The overall prevalence of diabetes in China in 2010 was found to be 11.6 percent of adults -- 12.1 percent in men, and 11 percent in women, according to the study published in the Journal of the American Medical Association (JAMA).

A woman has died in Qatar after contracting the MERS coronavirus, becoming the first recorded fatality from the SARS-like virus in the Gulf state, local press reported on Wednesday.

The 56-year-old Qatari victim, who already had chronic illnesses, died on August 31, a week after she was admitted to intensive care at a Doha hospital, newspapers quoted the emirate's Supreme Council of Health as saying.