What are the most important things to check during ultrasound that might impact birth choices?

[sarabecca]

I have very conflicting feelings about routine prenatal ultrasounds in general and I am now 19wks. pregnant and need to decide whether to get an u/s. I really want to know my baby's gender but I'm not overly concerned about any problems. That said, what would be the MOST critical things to check during an ultrasound?

I am considered getting a limited u/s to find out the gender and check the most critical things that might impact my choices regarding the birth. We are planning a home birth so part of me would like to check the heart to make sure there are no major defects that would make a hospital birth a better idea. What other things would be best to know *before* the birth? I remember sitting there during my dd's ultrasound while they checked a bunch of things that didn't seem necessary. If I get an u/s, I'd like to limit the baby's exposure and just check the most important things, kwim? I would LOVE any and all comments, suggestions, etc. I am really torn about this... Thank you!!!

[Cheshire]

Placenta placement and where the cord inserts into the placenta itself (not just where the placenta inserts into the baby).

[sarabecca]

Originally Posted by Cheshire

Placenta placement and where the cord inserts into the placenta itself (not just where the placenta inserts into the baby).

Thank you! The reason to check placenta placement would be to check for previa, right? But anything that shows up at 20ish weeks would only necessitate another u/s later in the pregnancy to see if the placenta has moved, which it does the great majority of the time, correct? I'm going off memory here so correct me if I'm wrong. And aren't there almost always symptoms of previa before labor? Or can it be a total surprise with no way to detect it beforehand?

And what is the reason to check where the cord inserts into the placenta? I don't know anything about that one.

Thank you!

[katelove]

I agree, placenta praevia would be my main consideration. The main symptom is bleeding after 20 weeks but not everyone with placenta praevia with bleeding. I would also consider placenta praevia with a consistent malpresentation or high head but these are late signs and can be caused by lots of other things too so it's not a highly sensitive test. You could consider having the USS later than 20 weeks to avoid the need to have another one later if it showed a low lying placenta.

This is an issue which concerns me also. My feeling is that the later the USS is done the lower the risk to the baby. I don't have evidence to support this as such (I don't believe any exists, either way) but I base it on what is known about USS and foetal development. As you have mentioned there are some congenital problems which would make birthing in a tertiary centre the safest option. Things which come to mind for me would be serious cardiac defect, diaphragmatic hernia and gastroschisis.

[cristeen]

If you're concerned only about placental placement, a later u/s would probably serve you better, since as you noted, it can continue to move after 20 wks.

The real purpose of the 20 wk u/s is to do an anatomical check. This includes imaging all the major organs, making sure they're present and functioning - making sure there are the correct number of them (kidneys, lungs), and that they have the right number of chambers (heart). Imaging the spine to check for neural tube defects, and the brain to be sure it is intact... these are things that can impact where a birth should take place and in what manner (c/s vs vaginal; local hospital vs regional). They also check for other things like club foot and cleft palate, soft markers for DS or other chromosomal anomalies, but most of the time those would not impact birth location. Essentially, the reason for the scan to be at 20 weeks is because the organs are large enough to be seen, but it's early enough for the woman to have the option to terminate the pregnancy if something major is found.

[MeepyCat]

Originally Posted by sarabecca

Thank you! The reason to check placenta placement would be to check for previa, right? But anything that shows up at 20ish weeks would only necessitate another u/s later in the pregnancy to see if the placenta has moved, which it does the great majority of the time, correct? I'm going off memory here so correct me if I'm wrong. And aren't there almost always symptoms of previa before labor? Or can it be a total surprise with no way to detect it beforehand?

And what is the reason to check where the cord inserts into the placenta? I don't know anything about that one.

Thank you!

A problematically positioned placenta at 20 weeks is very likely to resolve on its own, and would necessitate a follow-up u/s to check, but at that point, you'd be comparing the risk of harm from u/s (possible, but uncertain in nature and severity) to the risk of attempting to deliver with placenta previa (if you're one of the 6 in 1000 women whose placenta does not move, you'd be risking uterine hemorrhage, emergency hysterectomy and death - both yours and the baby's).

Six in 1000 is not such a high number (sorry, no link, got it from my midwife), but those are some lousy outcomes.

Previa does very often present with bleeding in the third trimester, but not always. One of the standard things that doctors (and nurses, and sometimes paramedics) do when presented with a women 6 or more months pregnant who is experiencing vaginal bleeding is to check her cervix for dilation. If you have placenta previa, however, a cervical exam can trigger an uncontrollable hemorrhage, and should not be performed. One would hope that medical professionals wouldn't muck around with these exams if you were actually hemorrhaging, but blood is a sign of early labor, and not all hemorrhages start big. So in the event that you had a previa, first, you would want to seek medical attention at the first sign of bleeding, and second, you would want people to know not to put anything inside you for any reason until and unless they were prepared to perform major surgery.

[DoulaVallere]

Originally Posted by sarabecca

Thank you! The reason to check placenta placement would be to check for previa, right? But anything that shows up at 20ish weeks would only necessitate another u/s later in the pregnancy to see if the placenta has moved, which it does the great majority of the time, correct? I'm going off memory here so correct me if I'm wrong. And aren't there almost always symptoms of previa before labor? Or can it be a total surprise with no way to detect it beforehand?

And what is the reason to check where the cord inserts into the placenta? I don't know anything about that one.

Thank you!

If the cord inserts into the membranes or edge of the placenta instead of centrally, you would want to make sure your provider did not put traction on the cord to help your placenta deliver and instead let it deliver on its own, because those types of insertions have a higher risk of the cord tearing away and causing hemorrhage.

[Cheshire]

If the cord inserts into the membranes or edge of the placenta instead of centrally, you would want to make sure your provider did not put traction on the cord to help your placenta deliver and instead let it deliver on its own, because those types of insertions have a higher risk of the cord tearing away and causing hemorrhage.

In my case last August when I delivered at 40 weeks I wasn't cleared for a vaginal delivery until 37 weeks because of marginal previa. I didn't know I had a velamentous insertion (the cord inserted into the amniotic membranes and traveled along the amnion before inserting into the placenta leaving the vessels completely exposed with no protection). I also had vasa previa where the vessels in the amnion traveled across my cervical opening.

If my doctor had found it on ultrasound I would never have been allowed to deliver vaginally and would have been given a c-section around 35 weeks. My son would have lived. Instead, when my midwife ruptured my membranes it started a cascade of issues with his cord. At one point the vasa pravia vessels tore and where the cord inserted into the placenta (the unprotected velamentous insertion) tore, also. He lost the majority of his blood in just moments.

Where the cord inserts is not just an issue for after the baby's birth and any type of cord traction. It can be life threatening to the baby before birth.

It is rare, but it can be diagnosed so easily if it is looked for. If you have any type of previa it raises the risk of cord issues and should be monitored even if your previa resolves itself. The placenta can grow to a higher part of the uterus and the part of the placenta that is near the cervical opening will atrophy but wherever the cord inserts does not change or move with the placenta. It can end up being a marginal insertion.

I wish someone had told me about this possibility when I posted the question last year about marginal previa. I didn't know what it was called and didn't know what to google. I do not mention this to scare you just to give you more info. As I said, it is so easy to look for on ultrasound and can save your baby's life.

Best wishes!

[RoseDuperre]

Cheshire, I couldn't read this and not post. Oh my gods, I am so, so sorry.



I am really surprised that when checking you for your marginal previa, both at the initial US and at the 37 week one, they didn't note the placement of the cord! (I too had a marginal previa until 36 weeks.) I am almost certain that my US did, but I'd have to check my records to confirm that. Isn't that part of what they are supposed to look for, if they're already checking your placenta? Am I off-base on that assumption?

Either way, I will definitely make sure they include this in any US placenta assessment in the future, should I have another low-lying placenta!

[OMama]

Cheshire - I am so sorry for your loss as well. Thank you for sharing your story with others.

That is the thing that came to mind for me too, well, vasa previa to be exact. They say this is rare but I am actually beginning to wonder how rare it is because it keeps coming up for me with couples I'm working with and in conversations. Recently I was about to start working with a couple and there was a slight concern about cord placement. The midwives were unconcerned but the mama felt like she really wanted to make sure, and at the second ultrasound they discovered she did have vasa previa. Their birth plans have now radically changed.

I would definitely do an u/s to check for these types of issues.

[sarabecca]

Cheshire,

I am so so sorry. Thank you for sharing your story. I had not heard about the potential issues with vasa previa or velamentous insertion before so I will make absolutely sure they check that if I go ahead with the u/s, which I am leaning towards doing now.


So it sounds so far like the most important things to check are:

Placenta placement
Location of cord insertion
Check for vasa previa
Heart
Diaphragmatic hernia
Gastroschisis

Anything else that would be critical to know before birth?
What about the brain and possible neural tube defects? What are the potential concerns with those two things that would change birth plans?

Hmmmm, the more I think about it, the more I wonder if I should just have the complete scan done. I wish I could find a comprehensive list of all the things they check at the typical 20wk u/s. I tried googling but I'm having trouble finding a good list.

Maybe a better question is: what do they check that is really unnecessary to know before birth?

Thanks again for all the info. It has been very thought-provoking.

[RoseDuperre]

Originally Posted by sarabecca

Maybe a better question is: what do they check that is really unnecessary to know before birth?

Gender.

But seriously, I'll let someone more experienced answer that.

[Cheshire]

Thank you all. We are still researching what the perinatologists and their ultrasound techs were doing at all of the many, many ultrasounds I had during that pregnancy and why it wasn't spotted. It was an extreme case and should have been easily found.

The more women ask for the placental cord insertion to be looked at the more doctors and ultrasound techs will think to look for it. According to the vasaprevia.org Website:

The issue of umbilical cord accidents (UCA) is that 25% of pregnancies have some involvement. Looking at cause of death, 2-4 cord accidents per 1000 births occur without the awareness of the OB community. UCA-VCI/VP are part of an overall pregnancy process which goes unaddressed in Obstetrical Conferences. Education is needed to improve the awareness of UCA and its losses which exceeds the 1-2 per 1000 stillbirths due to pre eclampsia.

So many unnecessary deaths. It is easy to diagnose if they just look for it.

Best wishes!

[kcparker]

Originally Posted by sarabecca

Anything else that would be critical to know before birth?
What about the brain and possible neural tube defects? What are the potential concerns with those two things that would change birth plans?

Hmmmm, the more I think about it, the more I wonder if I should just have the complete scan done. I wish I could find a comprehensive list of all the things they check at the typical 20wk u/s. I tried googling but I'm having trouble finding a good list.

Maybe a better question is: what do they check that is really unnecessary to know before birth?

Thanks again for all the info. It has been very thought-provoking.

If you ask your HCP, they should be able to provide you with a list. The anatomy scan usually checks for physical markers that can indicate other underlying chromosomal defects or physical anomalies that could present a risk to the baby for vaginal birth or in the neonatal period that might require more intensive medical support than an uncomplicated birth. At my scan, I know the U/S doctor checked the fetus for a 4 chambered heart, stomach, intestines, kidneys, neural tube defects, club foot, and took a lot of measurements (head circumference, stomach circumference, femur length) that they use for dating but also to make sure the fetus is growing appropriately, as behind-dates sizes or different measurements that indicate wildly asymmetrical growth can be an indicator that there might be issues with the fetus that need monitoring. They normally also check the face/jaw for cleft lip/palate (again, maybe not a problem, maybe a soft marker for other stuff). She also looked at placental placement and to make sure the cord had 3 vessels, and I think it's normal for them to check for insertion.

I think that if you are going to have it, just go for the whole shebang and ask for them to be as efficient as possible. If I were going to not care about certain things, I'd not worry about club feet or cleft lip/palate because they are correctable, and the gender check is PURELY for satisfying the parents' curiousity. I'd want to know about anything that might impact my choices about where to birth and what level of care the baby might need in the immediate neonatal period, and most of the anatomy scan is designed to look for that sort of thing.

[sarabecca]

Thanks again for all the info. I'll be calling my midwife tomorrow and discussing this with her. I welcome any other thoughts/advice/recommendations, etc.

[claddaghmom]

Originally Posted by Cheshire

Thank you all. We are still researching what the perinatologists and their ultrasound techs were doing at all of the many, many ultrasounds I had during that pregnancy and why it wasn't spotted. It was an extreme case and should have been easily found.

The more women ask for the placental cord insertion to be looked at the more doctors and ultrasound techs will think to look for it. According to the vasaprevia.org Website:



So many unnecessary deaths. It is easy to diagnose if they just look for it.

Best wishes!

ok that makes me really angry. It is not hard to check for that at all. :

[marrymeflyfree]

Originally Posted by kcparker

I think that if you are going to have it, just go for the whole shebang and ask for them to be as efficient as possible.

This is what we did...we had the 20 week scan, and I just told the tech that this was likely the only scan we'd be getting and asked if she could be as thorough as possible. I had a velamentous cord insertion and other placenta/cord issues with my daughter's birth, and asked her to pay particular attention to those things because of that.

[Turquesa]

Correct me if I'm wrong, but I believe that the 20 week u/s can also detect spina bifida in your offspring. And again, correct me if I'm wrong, but a hospital delivery may be worth considering in this case.

[sarabecca]

Originally Posted by Turquesa

Correct me if I'm wrong, but I believe that the 20 week u/s can also detect spina bifida in your offspring. And again, correct me if I'm wrong, but a hospital delivery may be worth considering in this case.

I think you might be right. And aren't there surgeries they can do prenatally if they detect certain things? I'm still very conflicted about whether or not to get the ultrasound at all. The more I research the potential damaging effects of u/s, the more I want to just skip it altogether. But, but, but...then I think about the rare possibility that they would detect something that would be critical to know beforehand. I just can't decide. Argh.

[Turquesa]

I haven't gotten any U/S this pregnancy but am debating if I should after reading this thread. Personally, I'm only concerned about getting one for every single prenatal appointment, which was the norm in my ex-OB's practice. It's the constant, routine exposure that concerns me. I don't think that one diagnostic ultrasound would hurt your baby. But I'm speaking from speculation here and not science.