Here are my reasons:
1) I had multiple sonograms in my first pregnancy, and every time they predicted a dire condition that proved not to be a problem.
I had one at seven weeks because my cycle had been short and they wanted to more accurately predict my due date. I was diagnosed with a low-lying placenta, and given all sorts of special instructions. What I didn't know at the time, because of my first-time mom naivete, was that a lot of placentas are low at that point, because they tend to grow up and out during the course of pregnancy. At seven weeks, there is not a lot of real estate in the uterus for the placenta. By the next ultrasound, the problem was gone. But I had stressed and worried and followed certain procedures for thirteen weeks, all of which proved to be unnecessary. Plus, the danger of a low-lying placenta is only in labor. It is a true reason for a c-section, but an ultrasound at seven weeks could not in any way predict where the placenta would be at the time of labor.
I had the standard twenty-week scan to check the chambers of the heart, sex of the baby, and positioning of organs and placenta. At this one, the placenta was fine, but Vicki would not get into the right position to see her heart, and "they" became convinced that she had a heart deformity. Again, if this were true, it would be a cause for special procedures in labor and immediately following (usually a NICU stay). I was ordered to come back at 28 weeks for another scan.
At the 28-week ultrasound, the heart looked great, but Vicki was breech and this caused numerous conversations and much worry and strife for me. Again, I should have been educated enough to know that she had twelve whole weeks to flip. A 28-week scan cannot predict breech birth! Naturally, she was head-down within four or five weeks.
By 36 or 37 weeks, my blood pressure was creeping up (no wonder, with all this unnecessary stress!), so I had to start having all manner of scans, non-stress tests, etc. Each one worried me more and more. Baby was small - no wait, baby was huge (baby came out perfectly average at 7 lb 1 oz). Fluid was low. Due date was wrong. Actually, original due date was right. Late pregnancy ultrasounds are just notoriously full of errors that impact birth.
I just don't want the stress this time. I don't want the worry. I want to worry if I have a real reason to worry, not an invented one that doesn't prove to be an actual problem. I am an anxious enough personality that "taking it easy" just doesn't come naturally when I feel that my baby might be messed up.
2) Routine ultrasounds - and especially "vanity" ultrasounds just for the sake of seeing the baby - have not been proven safe! Just because they are common practice for standard obstetric care in this country does not mean they are safe. This is just another one of the issues in our American model - we don't practice evidence-based medicine! Here is a great video clip from Mama Natural about the concerns her care providers presented about the safety of routine ultrasound.
3) The womb is dark, calm, fluid, and full of rhythmic body noise for a reason. I have to believe that we were designed that way. Every time I put waves in there, I disturb that environment. There are videos and stories of women whose babies turn away from the ultrasound wand. Or babies that get really active when those waves enter their home. We think it's cute on the screen, but it's not normal for them!
Here's a great blog by a Montessori mama on why she chose to forgo ultrasound and doppler, and how she trusts Nature and her child to form in the way that is proper.
I also read a beautiful story of homebirth in Holland. The American mother was surprised by the hands-off approach of her Dutch midwives, who gently insisted that healthy pregnancy and birth was her job, not theirs. When she asked why no ultrasound, I just loved their answer:
"We don't open doors that don't need to be opened."
I think that sums up my thoughts on it, too.
I have requested that our midwives use a fetoscope, which is a special kind of stethoscope for pregnant bellies. It's almost a lost art. A fetoscope cannot be reliably used to heart fetal heart tones until 20 weeks or later, so we have not yet started using it.
The main issue was practical, for me. Jeff and I wanted to wait until we heard a heartbeat to tell all our friends and family about the new baby. I wanted some kind of proof that there was truly a little human in there. Like the very clear signs that my body was giving me weren't enough! I needed something "scientific." We did use a doppler to hear the heartbeat at 12 weeks, so I could feel comfortable in announcing our pregnancy.
Our midwives left the decision to me and Jeff, but did recommend one ultrasound at 20-22 weeks, to see if development was occurring appropriately, and to check the sex of baby if we desired. We have decided to have this one scan, which will be in ten days or so.
Let me emphasize, before closing, that I don't think ultrasound is a bad idea for everyone, all the time. If your body is giving you indications that you have an issue, or if you are concerned about the likelihood of conditions that may come up because of your age or risk factors, it's probably a good idea to go ahead and get one or more. Do a cost/benefit analysis for yourself. But, just like the cesarean section, which is truly life-saving when really necessary, we have confused what is good in rare pregnancies with what should happen in every pregnancy.