NOGALES, Arizona -- Covered in dirt in the inky night, the newborn trembled as a stranger struggled to snip her umbilical cord with nail clippers. A smuggler and other migrants had bolted when the baby's 18-year-old mother screamed with labor pains.
But Lilia Ortiz couldn't just leave them in the harsh Arizona desert. Ortiz, 23, had walked two days straight to get this far. But she knew what it was like to struggle as a mother on her own.
The two women are part of a new wave of migrants. A decade ago, illegal migration was dominated by men. Now more women are making the journey, risking rape and even death to support their families.
The increase in women migrants occurs as beefed-up border security has funneled migrants through one of the world's most forbidding deserts, and as smugglers adopt increasingly violent tactics.
Some women cross with their children. Others leave them behind with relatives. Pregnant women, like Maria Perez, the 18-year-old who gave birth this week, walk for days through the desert in the hope that their children will have a better life as US citizens.
Rape has become so prevalent that many women take birth control pills or shots before setting out to ensure they won't get pregnant. Some consider rape ''the price you pay for crossing the border," said Teresa Rodriguez, regional director of the UN Development Fund for Women.
If caught by the US Border Patrol, women are often deported to Mexico's violent border towns in the middle of the night, despite a 1996 agreement between the two countries that promised women and children would only be returned in daylight hours, according to directors of migrant shelters along the 2,000-mile border.
Worldwide, nearly half of the estimated 180 million migrants are women, according to a report released in February by the Economic Commission for Latin America and the Caribbean.
A study released last week by US and Mexican migration experts, partly funded by the Mexican government, found that nearly half of all Mexican migrants living in the United States are women.
The female migrants are getting younger. Of migrants under 18 deported to Mexico, females accounted for only 2 percent in 1994, when the United States started cracking down at the border. Since 2002, they have made up nearly a third each year, said Blanca Villasenor, who recently published a book on Mexico's female migrants.
''It's very significant because it shows the country is losing its potential -- its youth, its reproductive force," said Villasenor, who runs a youth shelter in Mexicali on the California border.
Central American women face even more danger because they must first cross Mexico, where gangs and even immigration officials have attacked women, said Jesus Aguilar, a migrant rights activist in El Salvador.
''The normal rule, according to women who migrate, is that before leaving their countries they have to take the pill for at least one to three months to ensure that they will not get pregnant after a rape," said Aguilar, of the group Carecen Internacional.
Many Central Americans crossing Mexico hop cargo trains, where Aguilar said ''there's almost a 99 percent chance that a woman will get raped."
''The risk of rape is very high, not only by smugglers or by men in their same group, but also by criminals on public buses or on the cargo trains," he said.
Waiting with a smuggler for darkness in the popular jumping-off point of Sasabe, across the Arizona border, Gisela Anzures fiddled with a purple scrunchie on her wrist Tuesday and said she had heard the horror stories.
''It's very dangerous. The gangs show up and pat you down in a horrible way," said Anzures, a 28-year-old divorced accountant who left her 5-year-old son with her parents in Cuernavaca. ''It's no great pleasure to do this, but I'm fed up with the long hours and low pay in Mexico."
Twenty-five miles to the north, a US Border Patrol helicopter had spotted Ortiz, her aunt, Perez, and her infant.
After being abandoned in the desert by their smuggler, they were glad to be rescued.
Ortiz and her aunt were returned by the Border Patrol to Nogales, where they vowed to try again. Perez and her newborn daughter were recovering at a hospital in Tucson, according to Ron Bellavia of the Border Patrol. Mother and baby were in good condition.
Perez's baby daughter is now a US citizen.