This question was originally posted on Quora.com and was answered by Rufus Holbrook, 20 years as a Maternal-Fetal Medicine Physician That the needle I am using for your amniocentesis is 3 ½ inches long. Though I rarely insert more than 1 ½ inches. If you have a thick abdominal wall, I may need to get the 6-inch needle. Naturally, I am not going to mention these sizes or show you the needle unless you ask. That if your placenta needs to be manually removed after delivery (and of course you have an epidural anesthesia), I am going to have to place my entire arm up to the elbow in your vagina and uterus. Although it sounds strange, remember that a 7-pound baby just came out of there. That sometimes during a pelvic exam, I can see little pieces of toilet tissue that got stuck on your labia from when you wiped. I never say anything about this, and of course I don't try to remove it. That during your pushing right before the baby is delivered, sometimes a strong jet of urine comes out and I simply hold my gloved hand up to keep it from splashing all over my legs. You aren't aware of this, and we aren't going to tell you. That stool can come out as you push, and the nurses keep placing a new Chux pad under your butt to cover it each time. Another thing you probably aren't aware of (but your friends have told you will happen). Source