That sounds like a common side effect from spinal or epidural anaesthesia so the best way to avoid that is to avoid further anaesthesia like that. There are many many safer ways to manage labour via acupressure, water, massage, homeopathy, movement, selfhypnosis and the like all of which only increase your birthing potential in a way that anaesthesia doesn't. Investigate those, get your medical record and go through it with someone not connected to the hospital so you're getting an unbiassed view. What you're describing is a common side effect of having stuff done to your spine since about 25% of those procedures come with serious side effects and many more have short term effects just like what you're describing. It lowers BP when you have those drugs introduced into your body and the drugs are present in your system for some time afterwards. Here's a beautiful, powerful VBAC for #2! \/