I wouldn't be too concerned about how you lie during pregnancy affecting fetal position in labor. Researchers conducted an ingenious study a few years ago to investigate the correlation between persistent occiput posterior baby (baby facing the mother's belly instead of her back) and epidurals. They did repeated ultrasound checks during labor, the first as soon as possible after hospital admission in labor, the second within an hour after having an epidural or 4 hours later if the woman didn't have an epidural yet, and one at 8 cm dilation. They found the correlation--3% of women had an OP baby at delivery who didn't have an epidural versus 13% who did--but they found a couple of other things too: first, babies shifted from anterior to posterior in labor as well as the other way round, and second, back pain did not not correlate with the baby's position. (FYI: The reason the baby's position in labor is important is that OP babies are much more likely to be  cesarean or instrumental vaginal deliveries because they don't fit well through the woman's pelvis in the OP position.) The moral of this story is the way women position themselves in pregnancy doesn't matter, but what they do in labor does.

As to why epidurals are associated with persistent posterior babies, the most common theory is that they relax the pelvic floor muscles and it is their muscle tone that guides the baby into the correct position for passing through the pelvis. I speculate that it may be an indirect effect. I think that walking and position changes during labor help coax the baby into position. From my days as a doula, I can tell you that many unmedicated women instinctively sway, lean forward to do pelvic rocks, and so forth because it feels better, but once a woman has an epidural, she is content to lie on her back. Of course, both could be true.

-- Henci

I would agree with Henci's response, and would add that, if you do have NSTs, especially nearing your EDD, try to get them to place the sensors on you while lying on your side. I had numerous (unnecessary) NSTs at the end of my pregnancy and my baby ended up being stuck in a posterior position due (at least in part, I believe) to all the reclining I had done for these tests. This, of course, led to some difficulties during labour.

I think you are right to be anxious about the possibility of a false-positive (the test says there is a problem when there isn't). The NST has a high false-positive rate in general and, according to this systematic review (a structured study of studies on a particular topic), the NST has not been shown to be beneficial in high- or intermediate-risk pregnancies. Moreover, the NST looks for fetal heart rate response to such things as Braxton-Hicks contractions and fetal movement, and somewhere rattling around in my brain, I recall that until the fetus reaches maturity, the fetal heart rate doesn't respond to these sorts of stimuli. Don't quote me on that, though, because I might be remembering wrong. I suggest you ask your dr to show you research confirming the benefits of weekly NSTs because they certainly aren't harmless. A test result saying the baby may have a problem can't be ignored, which is likely to lead to an unnecessary induction, cesarean, and possibly a preterm delivery. If your dr can, then you will have to weigh the benefits against the risks of a false positive, but if your dr can't, then you may wish to decline.

-- Henci

My current pregnancy is considered "high risk" because I was diagnosed with pulmonary embolism at 13 weeks - therefor I'm on blood thinner injections.

I've had two previous, uncomplicated home births. (One with Amy Romano) My plan is to STILL have a home birth with baby #3. I have a home birth midwife whom I trust, and a maternal fetal medicine doctor so my blood thinner levels can be monitored and adjusted as needed during the pregnancy.

I give the background mainly because of my question.

My MFH doctor (during my last trimester) wants to do a lot of NST and fetal heart monitoring (20 minute strips in office). By a lot, I mean every visit.
Personally, I'm uncomfortable with this. I know that NST can be inaccurate, is there any information you can relay to me about 20 minute strips?

I'm just afraid that due to the machine they'll find "something". I know I have the right to refuse, but having some background research would be great! I can't find anything about the risk/benefits of such monitoring.

Add to that notion, that when my mother asked if they were worried about the baby during this pregnancy, they said "no. our main concern is mom. baby should be fine and unaffected by the blood thinners" then I wonder why they want to do all this amount of testing anyway.

Any research you've found would be great!!

--

Michael Robertson