ultrasound for placenta previa?

[travelmumma]

Hi Mummas.

I am 12 + 1 weeks right now, and saw my new doc for the fist time yesterday. We chatted about the tests I do and don't want. One that he would really like me to do is have the 20 weeks ultrasound to check mainly for Placenta Previa (and growth etc)....

I would really not rather have any more ultrasounds. (By 9 weeks I had already had 2).. I have been doing some reading that the placenta can move throughout pregnancy as the uterus grows anyway.. So even if they say I have it at 20 weeks, that doesn't necessarily mean I will have it when bub wants to arrive... right?

Do you Mummas know of any literature/websites I can read to get some more info on this?

(I should add that my HB midwife is fine with no more ultrasounds and I really don't want anymore for personal reasons)

[katelove]

Yes the placenta can move so if you have a placenta praevia diagnosed at 20 weeks a second USS will usually be recommended at about 34 weeks to see if it's moved up.

Most people (although not all) will have some bleeding prior to labour which will give an indication of praevia but in that case an ultrasound will be recommended to confirm.

I'm sure I read a paper recently suggesting that outcomes were similar whether women were diagnosed antenatally or in labour but I can't find it now. If I do I'll come back and link it for you. In the meantime you could put diagnosis placenta praevia into google scholar for more information.

[ameliabedelia]

I think a 20 week u/s can definitely rule out previa (in other words, if you don't have it at 20 weeks, you can't have it a birth as the placenta/uterus can only grow up).   And, since most OB's do an anatamy scan at 20 weeks anyway, they usually check the placenta at that time as well.  If previa is found, then yes, another u/s is usually done to see if it moved.   But, checking for previa is only 1 reason they do the 20 week u/s...the other reason it basically to check the baby's growth, internal organs, spinal cord, umbilical cord, etc.

[thepeach80]

If you don't want anymore and he wnts to rule it out, I'd wait till at least 34 wks to have one.

[Carobie]

The chances of you having placenta previa are rather rare (about 1 in 1500 first time mothers without other risk factors) however it is extrememely dangerous for you and the baby at delivery if you do have it. I had placenta previa with my first pregnancy and had zero symptoms (even more rare) I was planning a birth center birth at the time and had I not had an ultrasound I certainly would have had severe bleeding when I went into labor. It is true that at 20 weeks your placenta can be too close to the cervix but by 40 weeks it can be pulled upwards and out of the way, but if it is still too close to the cervix or covering by 36 weeks then there isn't enough more growth in the uterus to move it away at that point. However, if your placenta is not covering your cervix at 20 weeks you are in the clear. Most mothers with placenta previa do bleed at some point in their pregnancy, but not all. It just comes down to your comfort level with an ultrasound versus a rare but dangerous condition that would require a c-section. I was devastated to have to have a c-section with my first child, but so thankful that I knew about the previa before labor, that i made it to 38 weeks without a bleed, and that i now have a wonderful healthy 4-year old, followed by a home vbac 3 years later, and planning another home vbac in the next month. go with your gut and don't worry about it once you decide!

[fayebond]

Another vote for mama's gut.  My CP wants a 20w as well, for the same reason, plus I'm doing VBAC.  I don't really want it but I have a feeling its a good idea and am going with it anyway.  Trying to come up wit strategies to make the ultrasound tech not prod so hard on my belly, I feel sick all day after these stupid things.

I will add that I had the 20 week ultrasound, and all was well with DD.  Then at 37 weeks I told to get another US "just in case" to check on baby one more time before labor.  Well, she went breech during the US (mooned the monitor, I kid you not), and 3 days later she was born via CS for breech.  Whether she would have flipped without all that extra prodding on her head I will never know but darn if anyone is going to talk me into another US after 20 weeks!  

[travelmumma]

:) Going with Mummas gut it is lol!

I spoke to my HB MW today and said "I just don't know why I need one"

and she happily replied "Well seeing as you said that you wouldn't terminate anyway and that undiagnosed PP rarely rarely happens, I say we don't do it!"

Lol done and dusted!!!

:) Now to start researching everything else :) So fun!

[Alenushka]

I am confused by your HB MW statement. What does placenta previa has to do with termination? If you have placenta previa (Which happens in 1 in 200 women), and you  happen to fall into 10% in whom id does not resolved, the doctor will deliver via c-section.

Why is talking about termination?  I never heard of anyone terminating for placenta previa.

US has value even for people who would not terminate in case of defect.

For example , children with some defects fare better if born via c-section.

Other children will require to be bornin a hospital with cardiac specialist on the stand by..

Knowing if something is wrong doe snot mean termination; it simply means being prepared.

[TCMoulton]

Why would anyone terminate because of placenta previa - what an odd thing for a midwife to say!

[MeepyCat]

Another previa mama reporting in:

Placenta previa affects about 1 in 200 deliveries. I'm not sure whether to be more suspicious of the existence or the credibility of any study that found no difference between antenatal diagnosis and diagnosis in labor.

I dilated to about three centimeters the night my daughter was born, and gushed blood all over my house while waking people and calling ambulances. At the very least, you want people to know that you should not - life and death kinds od should not - have a manual cervical exam. (Additionally, you want to have prenatal rhogam shots if rh incompatibility is a possibility, and you'd like your blood typed and the local hospital to have a few units that match you, and my experience leads me to believe that some advance consultation with local hospitals might have made our lives easier.)

Anyway: my experience leads me to regard ruling out placenta previa as incredibly serious business. My daughter's birth story is somewhere in the back files of the birth stories section here - The Early Arrival of Vivian Rose. I wrote it in sort of a gratified haze shortly after Viv's birth, and it sounds very calm. It was terrifying to live through.

[LaughingHyena]

I presumed the comment about termination was to do with the other issues that would be checked for on a 20 week scan, rather than the previa.

[lisarenee25]

I hope so.

I had a diagnosis of previa at 13.5  weeks.  I bled.  The ultrasound peeps wanted me to come back every two weeks.  I waited until 24 weeks (and would have waited longer if it were not for the no sex thing).  It had resolved itself.  They wanted me to come in again to make sure, but I opted out.  Low and behold, I need another ultrasound anyway to confirm breech position - for a home delivery.

Ah well.  Late ultrasounds truly suck.  I was hoping to pop before, but doesn't seem like it's going to be so.

As far as the 20 week ultrasound, I would go with your gut.  If you need a peace of mind that everything is okay, then do it.  If you can live without it, then don't do it.  I don't think ultrasounds are evil.  When used appropriately, they can be life saving medicine.  I just think they are way overused and abused.
 

[fayebond]

Yay for mama's gut!

[Haelmoon]

If you are concerned about too much ultrasound for the baby, just asked for a placental location only ultrasound. It can be a really quick scan, but offer a degree of comfort. I did a C-section on a mom for previa today, but after her anatomy scan, we only looked at the placental edge in follow-up (28, 32, 36 and 38 weeks). Unfortunately her placenta remained previa, but she felt happy that we respected her wishing and not scanned the baby. She elected for trans vaginal scans, ad each took less than 2 min.

[Tizzy]

With my third, I opted for a single ultrasound around 34 weeks to check how many cord vessels (and insertion), location of placenta (for both placenta previa and it's location in relation to my C/S scar from a prior pregnancy), and anything overly obvious.

Everything checked out fine, I did have to listen to a few comments from the technician about how they couldn't see *everything* but I reassured her that it was okay.

This pregnancy I stupidly had the routine anatomy scan at 18 weeks which showed a low-lying placenta. So then I had to go back at nearly 38 weeks to double check the placenta location (it shifted dramatically, of course).  If I were to do it again, I'd skip the early one and just focus on our main concerns for a home birth - cord vessels and placenta location - at 30+ weeks :)

[fayebond]

I just had my US for placenta previa, and it was just fine.  Placenta is waaay up top above my belly button.  I wanted an US. I was even comfortable the whole time.  

BUT

The thing took 2 hours and 15 minutes.  That's in the room, not driving there, waiting, nothing, IN THE ROOM.  The tech said the new rules at her hospital insist on clear shots of everything from cervix to finger count, and if we could see it that didn't matter, it had to  be in a picture.  I brought my toddler and by the end both babies were clearly done with this process.  Everything looked perfect and I learned alot, but we didn't want to know the gender, and, lets just say I couldn't look away often enough.  I don't know if we will do this for the next baby, that took way too much of my time IMHO.  Everything looked great going in, and it nice to confirm that, but really, I don't know if I care enough about double checks to spend that much time (and have the suprise kinda ruined for me) on one extra double check.   *AHHH* Thanks for listening ladies, I feel better now.