They've been having samples of their sperm frozen in sperm banks.
Some say it's out of fear they might be exposed to chemical warfare or other dangers that could make them infertile. Others are worried they could die in combat. Many say they simply want their wives to continue infertility treatments they've already started.
The New Hope Center for Reproductive Medicine in Virginia Beach, Va., says it usually freezes eight to ten samples in a typical month. But officials tell The Virginian-Pilot that number went up to 30 or 40 this month.
The newspaper reports one Marine and his wife went to a local clinic the morning after hearing President Bush's State of the Union address. The man said he expected to receive deployment orders any day, so he wanted to leave what his wife called "the first deposit."
"We don't know what he'll be exposed to over there or how long he'll be there," she said.
Some men left several samples. Dr. Robin Poe-Zeigler, medical director at the New Hope Center, said the demand is so strong she had to buy a new tank to store the sperm.
The Jones Institute for Reproductive Medicine at Eastern Virginia Medical School in Norfolk, Va., says it had 60 requests to freeze sperm this month from military men expecting to head for the Gulf. Some couldn't get to the clinic in time because of the rushed deployments.
The surge in demand prompted the two clinics to begin offering free services to their military clients. The usual cost of freezing sperm and storing it for a year is about $245.
"It's a token of our support for the troops," said Mahmood Morshedi, director of the andrology-semen cryopreservation laboratory at the Jones Institute.