Chilean doctors successfully separated conjoined twin girls early Wednesday after a marathon 18-hour surgery widely followed in the South American country on television and the Internet.

The 10-month-old twins Maria Paz and Maria Jose are in stable condition even after losing a lot of blood and they are resting in the intensive care unit at Luis Calvo Mackenna Hospital, chief surgeon Francisco Ossandon said.

Women's health advocates said they will sue the U.S. government for allegedly violating the constitutional rights of young teens by denying them over-the-counter access to emergency contraception.

The suit is a new escalation in the decade-long battle over whether young teens should be able to get the morning-after pill without seeing a doctor first, and comes a week after the U.S. government blocked access without a prescription to those under 17.

Stillbirth is often caused by pregnancy complications such as problems with the placenta or preterm labor, said U.S. research published on Tuesday aiming to shed light on the causes and risks.

Ten years ago, little was known about the causes of stillbirth, a term that describes when a baby dies at or after the 20th week of pregnancy.

Scientists in the United States said Monday they have developed a vaccine that attacks tumors in mice, a breakthrough they hope will help fight breast, colon, ovarian and pancreatic cancer in humans.

Although studies on mice often do not translate directly into remedies that work for human subjects, researchers are hopeful because of the strength of the vaccine and the particular approach it takes.

Germany, one of Europe's fastest-ageing societies, has seen a sharp drop in the life expectancy of its poorest citizens, according to official data published Monday.

Workers with below-average incomes reached a median age of 75.5 years in 2010, down from 77.5 years in 2001, with the trend particularly marked in the economically depressed states of the former communist east.

In what's being called a landmark study, researchers used gene therapy to successfully treat six patients with severe hemophilia, a blood-clotting disorder.

The study was preliminary and involved only six patients, and other promising early attempts to use gene therapy against hemophilia ultimately failed. But a single infusion using the new treatment worked in some patients for more than a year, boosting their clotting ability significantly.

Shuffling in the dust among scrawny dogs and pot-bellied children, Kumke Lete wishes she could make it back across the border to Sudan's war-torn Blue Nile state to bring food to Doro refugee camp.

"For those that are able to go, they go. For people like me, I cannot go that distance," she said of the treacherous four-day round trip to the family farm, to bring enough grain to feed her seven children for two days.

More than 1,500 people have contacted China's environment ministry to urge rapid changes in the way it monitors pollution, amid accusations authorities are underplaying the problem.

The ministry said last month it was planning to amend the way it measures air quality to include the smaller particles that experts say pose the greatest health risk, inviting the public to comment on the proposal.

Breast cancer experts are cheering what could be some of the biggest advances in more than a decade: two new medicines that significantly delay the time until women with very advanced cases get worse.

In a large international study, an experimental drug from Genentech called pertuzumab held cancer at bay for a median of 18 months when given with standard treatment, versus 12 months for others given only the usual treatment. It also strongly appears to be improving survival, and follow-up is continuing to see if it does.

The two things that have brought Michael and Roslyn Lieb closer together couldn't be more different: Parkinson's disease and dance, one slowly taking away, the other giving back in ways they never imagined.

After tremors in his right arm and leg 11 years ago led to Michael Lieb's diagnosis with the debilitating brain disease, his wife became his caretaker. But two years ago, she developed a tremor, too. The diagnosis: Parkinson's.