A new book from Oxford University Press takes a fresh look at women in combat and finds that while the number serving in war zones has risen exponentially in the past 20 years, the research on issues important to female troops — health, family, career advancement and relationships — is lacking.

"Women at War," edited by retired Army Col. Elspeth Cameron Ritchie and Army National Guard Col. Anne Naclerio, doesn't question whether women should be in combat, since they have been for years.

Rather, it aggregates the scant data on the effects of war and military service on women, from the physical impact and psychological consequences to influence on relationships, financial stability, and long-term health.

Featuring 19 chapters written by 40 contributors, including 10 men, the textbook-style work is heavy on the academic research, with articles ranging from illnesses and mortality rates of women in Iraq and Afghanistan and post-traumatic stress to medical concerns, reproductive health, homecomings, motherhood in wartime and more.

Ritchie said she tackled the project largely because so little few advancements have been made in accommodating women on the battlefield.

"I published a paper in 2000 about the issues facing women on deployment — things like going to the bathroom, managing recent childbirth and breastfeeding, birth control. But when my fellow editor deployed to Afghanistan, she found the same issues. Why the reason for so little change?" she said.

About 15 percent of U.S. troops today are female, with the figure expected to increase in the future and more likely to enter the combat arms as opportunities expand. But as Army Surgeon General Lt. Gen. Patricia Horoho wrote in the foreword to Women at War, this "begs the question, what is being done to better understand and address" their needs?

"This book makes it clear that progress in understanding women's issues related to war and serving in the military has been made but much more research on these vital topics is needed," Horoho wrote.

Women at War delves into topics that even female troops are squeamish discussing — gynecological issues, birth control and reproductive concerns, sex, disease and death. Ritchie said part of the reason so few advancements have been made in accommodating women's needs on the frontlines is the reluctance to address them.

"Women don't want to admit they have different needs than men do," said Ritchie, who deployed to Iraq and served in Somalia and Cuba. "They tend to suck it up and drive on."

Roughly 770 female U.S. troops deployed to Operation Just Cause in Panama in 1989. More than 223,000 served in Iraq or Afghanistan or both from 2002 to 2011, 11 percent of the total U.S. force. Just over 2 percent of casualties in the two wars were women.

The sheer numbers and their projected growth, Ritchie said, should compel current and future leaders to educate themselves on the unique needs of women in field training or combat operations.

Those needs include how to go to the bathroom in full combat gear (many women choose to wear diapers and there's a piece of gear, called the female urinary diversion device that lets them evacuate through the fly of utility trousers); accessing birth control in remote locations, not only to avert pregnancy but to suppress menstrual cycles; and psychiatric care for issues more common to female troops, like eating disorders or post-traumatic stress related to military sexual assault.

"The military really hasn't tackled women health issues in a meaningful way. We are hoping to raise awareness of these issues so we can fix them," Ritchie said.

Despite the dense research contained in the 368-page book, Women in War suffers from some notable gaps, according to the editors.

Ritchie said she could not find an author willing to write about what it means to be gay and female in the military, and she found a notable lack of research about consensual sex in a combat zone. The opportunities for studies on both topics are wide open, she said.

"Most of the research focuses on military sexual assault. But we know very clearly that sex happens. It's better to acknowledge that and address the birth control aspect of it. A study indicated that as many as 12 percent of deployed women in 2008 had an unplanned pregnancy," she said.

While the book is an academic tome, with the hefty price tag of a textbook — $85 — Ritchie hopes it will be picked up by commanders and troops and be considered for integration into military leadership school training modules.

Ritchie and Naclerio have been making the rounds in Washington, D.C., speaking to the Uniformed Services University of the Health Sciences, the Defense Advisory Committee on Women in The Services and private bookstores and clubs, talking about the book's message.

Interested readers can pick up a copy at a 30 percent discount using the promo code AMPROMD9 at the Oxford University Press web site.

"We're hoping the conversation around this book really drives improvement in services for military women and veterans," Ritchie said.