A bipartisan group of House lawmakers is asking for an investigation into the Veterans Affairs Department's outreach efforts to female veterans, calling the issue critical to the future of the agency.

The letter, sent Thursday by 11 members of the House Veterans' Affairs Committee, asks VA's Inspector General's office to look into privacy policies, facility access and gynecological services available throughout the Veterans Health Administration.

"Female veterans are the fastest growing population served by [VA]," the letter states. "Women currently comprise about 10 percent of the population of the VA, but are about 20 percent of the active-duty components. It is critical that [VA staff] are prepared to serve the unique needs of female veterans."

Lawmakers said they are concerned with recent reports that VA "drastically underserves" female vets, either due to missing services, untrained staff or inadequate facilities.

VA officials said more than 635,000 female veterans are enrolled for VA health care, and about 400,000 actively use department services. Those figures have roughly doubled since 2000.

In testimony before the Senate Veterans' Affairs Committee last month, VA Secretary Bob McDonald said he has made recruiting gynecologists a departmental goal, recognizing the growing need. The department is also expanding the number of women's clinics nationwide.

But Rep. Dina Titus, D-Nev., said in a statement that she sees chronic problems in the system, "including a lack of women's health providers, problems with the coordination of care, and inappropriate treatment."

The letter does not set a timeline for the investigation, but lawmakers said they intend to take up the issue with the committee in coming weeks.