Risks that I have read and associated with the Del Em (menstrual extraction) include infection, getting air in the uterus, and puncturing of the uterus. The third risk is extremely dangerous, but not very likely so long as you go slowly and carefully. If you push against something and it does not give after a few minutes, take a break. Once your in the uterus, do not push against the wall. You will feel when you hit something. First you will hit the inner cervix, and you can gently push at upward and downward angles, and it will eventually give. This should be the only resistance you wish to get past. After that, the only resistance you encounter will be the uterus wall. You will not want to go past this. If you get there, do not push hard against the wall, and you should not be at risk for puncturing the uterus.
Getting air in the uterus should not be a great risk if you incorporate the one way valve into the del em properly. To ensure it is connected the right way, do a test run with a bowl of water. If you can push air back through the del em into your water bowl, you need to turn your valve around. Do not do the procedure if you do not have a one way valve. Getting air into a uterus is extremely risky. If air gets into the blood stream, it can travel up the the heart, and you could die. Do not let this scare you if you have a one way valve. The valve will stop any air from going back through the del em. Don't worry. I did this to myself over several nights, and I'm here, alive, typing this. Other possible outcomes of getting air into the uterus is absorbing air into the abdominal cavity, which is extremely painful and scary, but not necessarily fatal. Doctors have said that this procedure is no more dangerous than a medical abortion, and actually less invasive because you do not have to dilate the cervix or scrape out the contents with a sharp object. Do not attempt the del em procedure if you are more than 8 or 9 from your last missed period (LMP). The fetal tissue is often too large to pass through the cannula, leading to a greater risk of infection, incomplete abortion, and hemorrhage. Also, the cervix starts to close around this time period making it more difficult and uncomfortable to get the cannula in safely. The tube on my shout bottle was fairly rounded on the top because we managed to completely pull it from the bottle. If you have to cut your tube, I would suggest filing the sides down with a nail file to make it less likely you will cut yourself with a sharp tube edge. The width of our tube was about 5mm. If your tube is smaller, try to begin the procedure sooner than 8 to 9 weeks from your LMP. The bigger the fetal tissue, the more difficult it will be for a small cannula to suck everything out. Leaving tissue behind increases your health risks.
Infection is the most likely risk, though should not be a problem if you follow the procedure correctly. The uterus is mostly sterile, so getting bacteria from the walls of your vagina (which is always present) can put you at risk for infection. Also, leaving a partial fetus in your uterus can cause infection. The best way to avoid this is to take your time and go in a horizontal line across the uterus to ensure you get everything. If you perform the ME and get a fever within the next few days, you should go to the hospital. Don't be embarrassed if you have to go. Partial spontaneous miscarriages happen to a lot of women who are not even trying to abort. If this happens to you, depending on how far along you are, a doctor will prescribe you an abortion pill to help you pass whatever is left in your uterus, or you will get a D&C and antibotics.
Risks associated with vitamin C are mostly kidney stones. I have never gotten any, nor have I ever read any personal stories of women getting them. However, I have read if you have bad kidneys you should not try this. Also, if you do the vaginal insertion too much, you can irritate the inside of your vagina. This will pass and does not seem to cause long term damage. Do not use vitamin C if you are more than 7 to 8 weeks from your LMP. It will probably not work. Certainly do not use vitamin C late in pregnancy, as it will just cause premature birth.
I highly recommend only doing this procedures if you are confident you want an abortion and able to see it through. No one really knows the effects it has on the development of a fetus, so do not do this if you are not sure you want to abort. You simply cannot go through with having a child after doing this. I would recommend keeping medical abortions as a back up in mind. I also recommend reading as much about the topic as you can. The more prepared you are, the better off.