Parents who have good nannies swear by them. They like not having to deal with the politics of using a relative or with daily pickups and drop-offs at a center.

"Mornings aren't particularly stressful in my home since I don't have to bundle Megan out the door, dressed and ready," says Moira French, a working mom.

With nanny care, your baby stays in familiar surroundings, and she can nap and eat on her own schedule. Plus, she's exposed to fewer germs and may get sick less often as a result.

Some parents also say it's comforting to know their child doesn't have to vie with other children for attention as she would in a daycare setting. Naomi Langer, an architect in Los Angeles, says she was instantly sold on the idea of hiring a nanny because her daughter would get one-on-one care every day.

"I was worried that if she was in daycare, she wouldn't be the first one tended to when she cried or needed something."

Scheduling can also be more flexible with a nanny than with a daycare center — there may be wiggle room for last-minute changes. If an important meeting pops up at work, for example, you'll have better luck negotiating with your nanny than you would with a center that closes at the same time every day. (Assuming, that is, you haven't pushed the envelope by adjusting her work hours too often.)

What are the disadvantages?

Nanny care is largely unsupervised, making it doubly important that you find someone you trust, says Mary O'Connor, former president of the International Nanny Association. And because a nanny is a one-person operation, you'll have to scramble to find another if she decides to leave.

"We switched our son to a daycare center after our third nanny in 13 months quit on us," says Susan Webb, a mother in Amherst, Massachusetts. "We wanted a situation that wouldn't leave us in the lurch." (You can help lessen the disruption of a nanny's departure by specifying in your contract how much notice she has to give you — a month is customary, and gives you some time to look for a replacement.)

Your child's social life is another issue: Daycare and preschool automatically put kids in everyday contact with peers, whereas home care doesn't. To offset this drawback, you may want to sign your child up for classes or encourage the nanny to take her regularly to the park, story hour at the library, or on similar outings to give her that important interaction with other kids.

Although nanny care is no longer considered a luxury, it's still the most expensive form of childcare. Some parents in big cities pay as much as $700 per week or more — plus medical insurance, paid vacation, and holidays.

You may be able to pay less for a live-in arrangement, typically a dollar or two less per hour. If good nannies are at a premium in your area, you may need to sweeten the deal with perks such as a gym membership or unlimited use of a car.