Women in the military have access to some of the nation's best health care, which includes free birth control. But a new study shows that many women are not using it and the rate of unintended pregnancy is double that of the general population.
And today, with the Department of Defense having just ended its longtime ban on women serving in combat roles, an unplanned pregnancy could have wider ramifications not only for a woman's health, but for her opportunities for advancement.
An estimated 10.5 percent of active duty women, ages 18 to 44, reported an unplanned pregnancy in the prior 12 months in 2008, the last year for which there are statistics, according to researchers at Ibis Reproductive Health, a nonprofit organization that supports women's sexual and reproductive rights.
That number was higher than in 2005, when the rate was 9.7 percent.
In the non-military population, about 5.2 percent of women of reproductive age report an unintended pregnancy each year, according to the study, published this week in the February issue of Obstetrics and Gynecology.
The Ibis study was based on surveys of more than 7,000 active-duty women; the statistics were obtained from the Department of Defense under the Freedom of Information Act. Rates were equal among those women who were deployed and those serving stateside.
Women make up 202,400 of the U.S. military's 1.4 million active duty personnel; more than 280,000 women have deployed over the last decade to Iraq and Afghanistan.
"It's terrific that women are getting recognition for their role in combat missions and are being considered for all types of promotions in the armed services," said lead author Kate Grindlay, senior project manager at Ibis. "But for women to reach their potential, they must be able to access birth control for their personal health and well-being."
About 900 women had been unable to deploy in the past year due to a pregnancy, either planned or unplanned, according to the study. The highest rates were among younger women with less education who were either married or cohabitating, researchers said.
The authors of the study say that an unwanted pregnancy not only disrupts a woman's military career, but takes a toll on military readiness because pregnant women cannot be deployed or must be evacuated from war zones. They say the military needs to take a more "comprehensive approach" to address the problem.
A July 2012 Ibis study, based on women deployed over the last decade, revealed they face a variety of barriers to accessing contraception. Women said they did not speak with a military medical provider about birth control before they deployed overseas -- either it was never offered or the woman never asked.
Military policies that forbid sexual activity between fellow service members "led some women to think contraception was not available or not needed," said the report.
Others said they had trouble getting preferred types of birth control -- the IUD, for example -- or adequate supplies before deployment.
"In addition to these access barriers, the high rate of sexual assault in the military also puts women at risk of unintended pregnancy," said the July study.
Abortions are only provided at military hospitals in cases of rape, incest or life endangerment. A woman must either risk an abortion at a local hospital during deployment or be sent home. Tricare, the military insurance plan, does not cover an abortion.
"Women who are deployed in Iraq wouldn't have any abortion options and must be evacuated and it could compromise confidentiality and access to care," said Grindlay.
Navy medical spokesperson Shoshona Pilip-Florea acknowledged that unintended pregnancy rates had been high, but the Navy's own surveys had "noticed the trend" and implemented programs to address the problem.
"It has a huge impact on mission readiness, especially as we are changing to a defense where women can serve and it becomes even more important to enable them to protect themselves," she told ABCNews.com.
Pilip-Florea says that the Ibis survey is based on data that is five years old and many changes have been underway since 2008.
The Navy's own data shows that the number of unintended pregnancies is now "closer to the general population" -- at about 6 percent, according to Pilip-Florea.
The Navy's Sexual Health and Responsibility Program now provides pre-deployment education on birth control and family planning, in accordance with a campaign by the Department of Health and Human Services to combat unintended pregnancies.
Navy surveys show women had a wide variety of reasons for not using birth control which contributed to an unintended pregnancy: 1 in 4 said she was "not sexually active," according to Pilip-Florea.
"These data suggest that women who are not currently in a relationship may not feel the need for birth control, and that it's important for health educators and clinicians to help young women think about the benefits of being ready when and if she does become involved in a sexual relationship," she said.
Pilip-Florea also said many young women have an "old perception" about the use of long-acting reversible contraceptives like an IUD and the injectable hormone Depo-Provera. At one time, the IUD was not given to women who had not previously had children, but new recommendations have changed that.
Other young women are misinformed about the reliability of the birth control pill, which must be taken at the same time each day, or condoms, which can break.
Popular forms of contraception, like the "ring," also have to be refrigerated, which can be difficult when serving for months at a time on a ship.
"The study cited a couple of instances of misinformation and fear of reprisal, but from the Navy's perspective, we believe it is central to the equipment of our sailors and Marines to protect against unwanted pregnancies for mission readiness," said Pilip-Florea.
Since December 2012, Navy policy requires that women are offered contraceptive services before they receive their orders for operational duties.
Service members usually get three to six months between time of orders and actual deployment, allowing "ample time to stabilize" and physically adjust to their chosen form of birth control," said Pilip-Florea. The Navy also provides a long-term supply of birth control pills, for example, including "a couple of months extra."
ABCNews.com contacted the Army for comment, but did not get an immediate response.
Advocacy groups have pushed for legislation to give women better access to birth control and to abortion, according to Greg Jacob, policy director for the Service Women's Rights Action Network (SWAN), whose mission is to secure equal opportunities for active-duty military women and veterans.
The Department of Defense now gives women access to the so-called "day after pill," Plan B, which is available over-the-counter at medical treatment facilities.
SWAN also supported the 2011 March for Military Act, sponsored by Sen. Kirsten Gillebrand, D-New York, which pushed for lifting the ban on elective abortions at military hospitals, but was not enacted.
But the very nature of military life and its chain of command can make obtaining birth control onerous," said Jacob.
"They allow you to go to the hospital, but you have to ask permission," he said. "Particularly with the younger troops, they have to check with a platoon sergeant, get a pass, and get a chit that says what you were treated for and what your duty status is, and turn that in. The system is in place for millions of people to be accountable, but the level of privacy is not the same as in civilian life."
Women have access to regular preventive care, but educating military doctors to ask a woman if she is sexually active or needs birth control is important, he said.
Jacob suggested the military look to universities as models for educating about reproductive services. "It's the same sort of demographic -- young people in a restrictive controlled environment," he said.
Jacob said the end of the longstanding ban on women serving in combat will have a positive effect in empowering young women.
Over the years, critics of full integration have argued that men and women serving in combat could be distracting and create a "sexually charged atmosphere." But Jacobs said the new policy will go a long way to end sexual assault and, as a consequence, some unintended pregnancies.
The military already has strict rules forbidding sexual relationships between fellow soldiers, according to Jacob. "They have all the tools in place for dealing with issues of behaviors."
"From a harassment and an assault perspective, one of the key things we have found is the issue of the two-tiered second-class soldier culture," he said. "By fully integrating the troops and members feeling a part of the team, that type of behavior is reduced."
For Jacob, who served 10 years in the Marines, overseeing and reporting to women, a fully integrated military raises standards for all.
"Some of the women who I worked with are the best Marines I ever served with," he said. "My philosophy is there should be one standard for the Marines, not a separate one for men. It raises the entire performance standard of the regiment."