In selecting a midwife, I think number of births and actual experience is a much more important factor than the amount of time that one has been certified as a midwife. In determining experience, I would also take into account such factors as whether a midwife had served as a doula or apprenticed for a period of time under a busy midwife, as someone might have a great deal more experience in actually seeing births and issues that can arise if these are taken into account. There’s no hard and fast numbers for me, but I would be looking for a midwife who had seen as many complications as possible and had a solid plan for working through them (including transfer of care, when appropriate).
I think the issues that would necessitate a hospital transfer will vary from practice to practice, and you’ll definitely want to bring that up with the midwife right away (as well as making your own decisions about what you are comfortable with and what YOU feel would be better handled in a hospital than with a homebirth). For example, the midwife I chose for my pregnancy was willing to work with patients who had gestational diabetes (I did not have it) as long as they were under the care of a doctor or endocrinologist who would share medical records and the GD was kept in check during pregnancy. She had a particular endocrinologist who she regularly worked closely with. But she was one of the few midwives in my area who was willing to work with GD patients. She also performed twin deliveries (I’m not sure all area midwives do, although I believe several others do, and I’m not sure of any of their stipulations on a full-term labor with twins, as some research tends to indicate that twins may be ready for natural delivery earlier than a singleton pregnancy). She was very open to either IV antibiotics or minimal treatment for a group B strep positive mother (which I was) and fully informed me of all available options and the risks/benefits of my decision, as well as encouraging my own research and giving me a couple of weeks to make my decision (although had I chosen the IV antibiotics, I would have needed to notify her a minimum of approximately a week before my labor to ensure that she had them available). She also saw patients who had some small cysts, as long as they submitted to regular monitoring and US as requested.
Pre-eclampsia or pre-term labor (prior to 36 weeks) would have necessitated a transfer of care, and dependent on circumstances, some other risk factors that my midwife would have been unwilling to take on were placenta previa, abruption, and certain situations if there was a cyst which could have been a complicating factor in delivery.
Obviously, the amount of lead time on any of these factors could be widely variable. Pre-eclampsia can show up quite suddenly, and a cyst that is close to the placenta could potentially grow to cause an abruption whereas it had not previously been a problem. However, in some cases, such as the cyst, you might have had early warning of the potential problems that could develop and have time to determine whether you were more comfortable with transferring care early, before an actual problem arose, in order to have continuity of care, or to continue with midwife care even though it may necessitate a transfer at a later date.
I’d also be interested in knowing what type of working relationship a midwife has with local hospitals. I had my previous birth in a free-standing birthing center, but as it is around an hour and 45 minutes to the closest to me (where I would need to go for pre-natal appointments, even if I had a home birth), it wasn’t as viable an option to me when I have a little one just under a year and a half! My previous midwife had agreements with some local practitioners which allowed her to work hand-in-hand on care, although she had no hospital privileges. I’m currently seeing a group of CNMs locally who only do hospital deliveries, and one of them was formerly a birthing center midwife. She mentioned to me that the reason that she now practices in hospital is because she feels that is where women most need an advocate – that there are midwives providing the natural birthing options women want at home and in birthing centers, but the minute their care is transferred they generally lose everything. So that could be a consideration in choosing, if you feel there might be circumstances that would need a transfer (or even if you don’t, whether or not they would be able to provide any level of care if a change of plans was needed).
And there are also things that may necessitate a transfer during/after labor, as well, so be sure to talk to your selected midwife early about all aspects. Personally, it took 40 minutes after birth to deliver my placenta with my first. My midwife would have begun recommending a hospital transfer after 45 minutes and required one if the placenta had not been delivered within an hour, just in case of hemorrhage.