Purpose of a 40 week ultrasound??

[kristin1924]

Hi mamas,

I am 40 weeks pregnant tomorrow (my OB/midwife office had me as overdue because of my LMP date, OVER my conception date). They gave me a stress test and the baby is fine, perfect. My midwife wasn't in today, so I saw one of the very impersonal doctors at the practice. Even though I see my midwife tomorrow at another appt, this doctor just set me up with an ultrasound before I meet with my midwife.

What is the purpose of this? I mean, he actually agreed with me about how my conception date (day 21 of my cycle back in July) is the true date. And they know I won't induce if not necessary. But why the ultrasound tomorrow? I have already had 2 or 3 in this pregnancy because I was diagnosed at 16 weeks with low-lying placenta, but then was cleared later on.

Should I cancel the ultrasound? My mother and Aunt are freaking out about me having this so late at 40 weeks. They didn't want me to have any U/S at all with this pregnancy, but I chose to do so. THanks for any info!

[MaerynPearl]

I had one with DS however we had had complications and failed an NST and they did it to be sure that he would be okay if I were induced (I cannot tell you the exact reasoning behind it, it was over 7 years ago... but it ended up being fine to induce)

Without problems, I see no reason to do it.

[Funny Face]

They consider it a 'precaution'. They will likely be checking baby's heart rate and reactivity, fluid, etc.

Basically, they are probably trying to find a 'necessary' reason to induce, imo.

[MammaB21]

Originally Posted by Funny Face

Basically, they are probably trying to find a 'necessary' reason to induce, imo.

And for this reason I would decline the ultrasound. I may agree to one at 42 weeks from my conception date if it meant being able to continue on without induction or c-section, but 40 weeks? No way, not without valid reason.

[kristin1924]

Ok this is great, I needed this info from all of you. Thank you for this. I really feel in my heart that if I do not go into labor tonight, then I will call in the morning and cancel, but keep my midwife appt. I really feel wierd about having this U/S this late in the game, when I passed the stress test today and I am not dilated yet. I mean, even though it took me 2 years to conceive this baby, the pregnancy has been pretty strong.

[fairyannanicole]

Ok, I cannot speak for other people who have been pressured into having an ultrasound once the doc decides you are overdue. I will speak on my experiences. All mine have been done to scare me, telling me how HUGE the baby was, both times I accepted an US past term (my first 2) My oldest was measured at 10 pounds he weighed 7 12, my second was measure at 12 pounds, he weighed 7-10. It was a fear tactic because I refused to be induced.

[RedOakMomma]

I don't think it's necessarily that they're looking for an excuse. Do you get that vibe from your dr.? If you don't, then don't worry about it.

I got an ultrasound when I was 39wks 6days with my first pregnancy (twins). For me, they were checking fluid levels, checking for growth, checking the health of the placenta, and checking the size (weight) and head size of the baby. They also wanted to confirm positioning (since baby b was breech).

My birth plan said that I didn't want to have labor induced, and my doctor was behind that. He said he would feel more comfortable, though, if I could follow up the NSTs (which were all great) with an ultrasound at my due date, so we could be sure that the babies were doing well, that they weren't experiencing growth retardation, and that their head sizes weren't too big for my "untested" pelvic opening (which, I know, is a big-time usually, but since baby b was a breech extraction--pulled out by his feet--they needed to know that his head wouldn't get stuck...it didn't have time to mould to the birth canal).

I was totally behind the ultrasound, because it gave me the reassurance THEY needed to let me go into labor naturally. Going past 40 weeks is a big deal with twins...and I could tell my OB was trying to honor my wishes, but himself felt a little nervous. After the ultrasound, he said the babies were doing great and seemed a lot less concerned.

I never got the feeling that the ultrasound was looking for an excuse to deliver. Not all OBs and practitioners are like that.

[westcoastlady]

When I was slightly overdue with DS they scheduled an ultrasound as well to check for fluid levels. I never ended up having one because I went into labour, but my friend was two weeks late and she have a few US in the last week. She said they were really quick and just checked to make sure there was enough amniotic fluid.
But then again, our hospital is very naturally minded and they won`t even consider inducing you for lateness until you are at least 10 days late. They have even let people go to 17 days +.
They may also be checking you placenta, because if you become really overdue it can start to deteriorate (not until like 42 or 43 weeks).
If you do decide to have the US, I would do some research before hand so that if they do try to pressure you or scare you, you have information that can back up you desire for a natural birth.

[BlackSheepPDX]

I'm not anti-US, which it sounds like your aunt/mom are for starters.

My first pregnancy was with homebirth/freestanding birth center midwives. I was NEVER under any pressure to induce or have any unwanted interventions. The midwives suggested an US at 41 weeks for me, to make sure things looked healthy (placenta, fluid, baby movement/HR, etc) and that there was no reason to be concerned about continuing to wait for labor to happen when it happened.

I don't see a problem with having an US, and then standing by your birth plan and your dates as you wait for labor to start on its own. I don't believe a late term US is a scare tactic.

[nudnik]

If the reason is to check for weight or fluid, palpation will do a better job.

[HeatherB]

I would definitely avoid an u/s at this point, unless there was a clear indication (significantly slowed movement, palpation suggests a problem, etc.). Far too often, a late-term u/s is used as a scare-tactic to force induction.

[teenyxdoodlez]

Sounds like everyone has pretty much covered everything with great advice but I just thought i'd throw my two cents in too. ...(Although i'm sure it's not unheard of) I've never heard of anyone having a U/S beyond 25-30wks unless they were WELL beyond their due date OR preggies with multiples (or have had any other complications during the pregnancy). Usually for the reason of checking fluid levels and making sure babe wasn't under any stress. I'd say if things have been going smooth for you the entire time and you don't really see any reason to have one, just decline. Maybe if in a week or two you still haven't had the babe then it would be best to get one to make sure all is well, especially if your not up for induction!

[umsami]

Since you have an appointment with your midwife tomorrow/today, I would just hold off on the U/S until you talk with her. She may feel that one is necessary as well--or at least offer reasons as to why the OB suggested it.

I always end up with lots of U/Ss and NSTs near the end of my pregnancies due to gestational diabetes. But then again, I'm high risk. If you are not, then I don't think you're being unreasonable for saying... "hold on a minute... why are we doing this... what do you hope to learn from it... etc."

[gradstudentmommy]

With my first, the doctor scheduled an ultrasound when I was 41 weeks, 3 days. I went into labor at 41 weeks, 1 day so I never had the ultrasound. She said she wanted to make sure I still had adequate fluid and that the placenta hadn't started breaking down. She knew I didn't want to be induced and she said it was fine to wait until 42 weeks, but that it was a good idea to check the baby. She didn't say anything about checking the size. She said ultrasounds are terribly inaccurate at determining size.