I having a homebirth for baby #3 and will be hiring a doula. I've had a doula for my two previous births (scheduled c/s for breech and very, quick and easy Hypnobabies VBAC) and I loved having a doula. I could have gotten by without one, but having the doula was wonderful. I expect this next birth will be fairly quick and easy as well, but having the extra support will be great.
I am a doula myself and have attended births at home, at birth center and in the hospital. I think it is important to remember that a doula's job and a midwife's job are different. Not all midwives have the view that a doula is unnecessary at a homebirth. Many appreciate the help of a doula. Asking your midwife how she feels can give you valuable information about whether or not you should.
When does your midwife come? A doula comes when you feel you need her to be there. Midwives often come to check progress and leave if you are in early labor.
How many clients does your midwife take each month? If your midwife has another birth that is happening faster than yours, she will not be with you. If there are two births going on, she may be going back and forth. You may also have a back-up who doesn't have the same philosophy of a midwife's role. It is important to ask YOUR midwife what she thinks about doula support at home and when she normally comes.
Is this your first birth? Your first unmedicated birth? Your first VBAC? Your first homebirth? If so, you are more likely to benefit from a doula.
How many kids have you had and how have your labors been? This isn't fool-proof because you can be surprised, but if you've had several kids and tend to have fast births, you may not need a doula. If your births tend to be long or if you haven't had enough to have a pattern emerge, maybe you do want a doula.
How is your partner during birth? I've taught childbirth classes and showed birth videos where the birth partner is behind the mom in the birth pool as she gives birth. Almost all of the moms thinks this is wonderful, but not all of the dads/partners do. Be honest about who your birth partner is and listen to your birth partner. If your partner is telling you that he wants a doula or needs help or doesn't think he can handle it, listen to him. Doulas can help the partner be more involved by keeping him calm and giving him guidance. Doulas can also allow partners to get some rest and stay fed so that they have the energy to really be present when they are needed most.
A doula can help with other children, but this is outside the normal scope of doula services so it should be discussed with the doula in advance.
Choosing the RIGHT doula for you is very important. Stating your expectations and being as clear as possible about how you want her to help as well as just the basic personality match can help you chose a good match for you. Most doulas know how to help and stay out of the way. Doulas can also take pictures so that your partner can experience the birth directly instead of behind the camera.
I would say that if you aren't sure, go ahead and meet with a few doulas and see if there is anyone you click with and discuss how they can help you. Listen to your gut.
Hope everyone has wonderful births with or without a doula!