Conflicting Ultrasound due-dates

[chrissy1981]

I have had two ultrasounds each giving be a different fetal age and due date. My first untrasound at 10wks put my due date at 6/5/10, 28wks pregnant as of today. I had another one today because durring today's checkup my fundus measured 32wks. Today's ultrasound put size and developement at 31 1/2 wks, new due date at 5/20/10. There is concern that because my previous child was quite large at birth (10lbs, 2oz) that this one will also be large and warrent a repeat c-sec. I am hoping that this child will be a more normal size as I'd like to attempt a vbac. When my Dr. got the ultrasound results with the new fetal age, she refused to modify my due date stating that the baby is just big, the 6/5/10 due date remains and is pressuring me into a definate c-sec. ( I am fine with another c-sec if it is deffinately warrented, but would like to try a vbac if the baby is a reasonable size). I am concerned that if this new ultrasound is correct and i am almost 4wks further alon then the DR. will admit to, A.) which ultrasound is more likely correct (the 5/20/10 due date confirmed the conception timetable I've always believed in even when the first ultrasound contradicted it, I knew the conception week because i went on vacation and forgot bc) B.) if i go into labor naturally around the 5/20/10 due date, will the Dr. stick to her guns and say it's to early and try to stop it. ( My concern there again is alowing me to continue to gestate and the baby growing to large), C.) If the due date is in fact 6/5/10 and the baby is just large, would there be any risks involved in a planned induction at an earlier date to try to control the baby's birth weight? My previous c-sec was over 9yrs ago so I'm assuming any chance of a vbac uterun rupture is minimul. I am just concerned about the inacurate dates and the pressure to have another c-sec.

[LosingMyMindInGA]

You need to call the hospital L & D unit itself. I've had THREE babies in military hospitals and frankly my experiences with military was FAR more liberal and patient friendly than civilian hospitals.  What military facility are you delivery at?  

I was told by other docs in my area (civilian now) that the hospital here does NOT do VBACS at ALL, that NO docs around here will perform them and they most certainly won't INDUCE a VBAC.  Well My last child in Aug 08 was an induced vbac and I have the same doc this time who is going with doing a VBAC again as long as all goes well.  Speak to whoever is in charge of the L & D unit.  Remember, when it comes to military hospitals...Your HUSBAND is the military member NOT you...you can push and threaten whereas he can't.  Trust me I know.  I chewed a Captain up one side and down the other so bad he refused to come back and see me.

[chrissy1981]

My first c-sec was due to what the Dr. called failure to progress. I've also read reports that say that an ultrasound may have a +/- of up to two week descrepancy when done in the 3rd trimester, but a 3+ week descrepancy should change the due date. I've also asked the Dr. if we could try a planned induction to keep the baby's size in check. I asked her this before the new ultrasound and she told me that elective inductions at this hospital arn't done before 39weeks (thus my need for a confirmed due date). But when the results from the most recent ultrasound put the baby's size at almost 4 weeks ahead, she now says that the hospital just doesn't do inductions on vbacs due to an increased rupture risk. (I've also looked up statistics and studies and found that the increased risk is very minimal and can also be linked to other factors that necessitated the induction in the first place, rather than just solely the vbac it's self) I am very concerned that my wishes will be ignored as in the end, I will be subjected to the hospital's policy and the fact that I have no say in who delivers my baby (there are several OB Docs at this clinic and the one who delivers is just the one who happens to be working that day) and it will be up to what the Dr. will be willing to do. My husband if AirForce and this is a military hospital with military doctors. They are all about policy and protocall. If I refuse the Dr. deteremined treatment or opt to have my baby at a civillian facility, then I will not be covered by our insurance. I was told by the Dr. that I am lucky they are "allowing" me to even consider a vbac.

[Victoria01]

As the other posters have said, early ultrasounds are far more accurate (usually within 3 days) than a later one (which can be off by as much as a week or two). My baby measured on target up until the 24th week and then started measuring large by two weeks. My OB will not change my due date because he is just a big baby, but induction will be talked about when I go back in on Wednesday.

Since there is a 16 day difference between the due dates, I don't think the doctor would stop natural labor as you would still be considered full term. (I'm not sure where you are coming up with 4 weeks difference...)

[LosingMyMindInGA]

I agree with the above poster.  However, keep in mind that third trimester ultrasounds aren't as accurate as first trimester.  The measurements could easily be off either way.  With you last child were you allowed to labor but ended up with a c-section becuase baby wasn't fitting in the birth canal?  Or did they just assume you couldn't labor and did one?  The difference in those two types of situations could make all the difference in the world when opting for a vbac versus repeat c-section.  Trust me, most of the women around here who read my posts can tell you I am EXTREMELY Pro-VBAC having had 4 and working on a 5th myself.  But when there is medical necessity a repeat c-section is warranted.  Perhaps if you gve us more information as to why you had the first c/s we could give you some better advice.  

I will say that SOME (not all) docs do NOT do vbac becuase of insurance/acog restrictions.  While some of those docs will come right out and be honest, other docs will just look for excuse to do a repeat/elective c-section.  If you really concerned you ALWAYS have the option of a) getting a 2nd opinion with another non-affiliated doctor or b) requesting copies of your medical records and having another doctor review them for you.  

[Lizzy_anne24]

Go by your first u/s as babys develop the same up til 12 weeks then it's all individual. So it might be a big bub. A friend of mine is induced at 36 weeks due to having large babies rather than c section. The only thing to look at with vbac is y the need for a csection for previous pregnancy. If it's due to narrow pelvis and bub couldn't get through then chances r same thing can happen again. Ask your on y they recommend a csection over vbac. I was lucky and my vbac was straightforward
good luck