Hey Brittney!

 Great response! I love images you have attached as well. When I was reading an article it describe placenta previa as partial or complete. So it is nice to have additional terminology to add to it. 

 I also was thinking anterior placement of the placenta puts the mother at a higher risk for placental abruption. I understand it doesn't have direct cause on child birth, but still a thought. Do you think that an anterior placenta is a slight cause for concern? Or can possibly cause the mother to be even more cautious than usual?

Classic image! So helpful! Like you said, the placenta will move up as the uterus grows. Because of this, when we see a marginal previa, we are not too worried, because we know the placenta still has some moving to do. Thanks Brittany!

Hey there Leah! 

 Great response, it was very informative. I like how you italicized relative because it removes the assumption for beginners learning embryology that placenta is like detached and just moving around the uterus as the fetus grows. 

I am still trying to my head wrapped around this whole maternal and fetal blood "do not mix" from the lecture. Would you say the process is comparable to gas exchange in the capillaries ?

Great image! Those spiral arteries are CRUCIAL, pay special attention to them!

That's an interesting hypothesis Zuly although I don't completely understand. Are you saying that damage of the uterus could effect where implantation takes place? I wonder if a blastocysts could implant at the same spot as a previous implantation? (Dumb random thought)  I like you picture as well I would probably agree and say that its partial obstruction of the cervical canal. Is the fluid above it form the gestational sac? 

Hi Zuly !

 Thank you for knowledge drop! I didn't know poorly vascularized areas in the fundus of the uterus increase the likelihood that the placenta will cover the cervix. I wonder if it because like the examples in the video provided in cases of scarring and multiple pregnancies cause the placenta to favor a side? But would this also suggest the blastocyst favors to implant in an area of high vascularity? I also wonder if it this idea can have the reverse effect? Like a poorly vascularized lower uterine segment causing the blastocyst to implant higher?

  I would also like to think the image represents a partial placenta previa. This article I read leads me to think so. 

https://parenting.firstcry.com/articles/common-placenta-positions-an-overview/

Hi Zuly! That is an interesting point about the lack of vascularization post-surgery, post-trauma, and post-pregnancy. It does make sense to me since the area of incision or trauma would likely develop scar tissue and thus be less vascular. I read this article that did an analysis on patients who delivered via C-section and the subset of cases that were indicated by placenta previa. The study found patients with previously scarred uteruses who delivered via C-section because of placenta previa accounted for ~11% of the C-sections compared to patients with non-scarred uteruses at ~6% of the C-sections.

Hey Zuly!

This picture is a bit confusing to me because of the bladder in the image (should be inferior to the UT) and the appearance of the placenta looks a little funky... 

Here is a more classic image of previa on ULS. 

Hello again Candee!

I believe the other previa condition that you mentioned is Vasa Previa!

This is when the fetal blood vessels are really close to the internal os of the cervix, but still in the amniotic membrane. These vessels can become compressed by the fetus during birth and this can lead to decelerations of the fetal heart. There is also a high risk of bleeding if the mother delivers vaginally. A C-section is typically done in these cases.

Here are some images to help with visualization! Also Radiopaedia had some great information on this :) 

https://radiopaedia.org/articles/vasa-praevia-1?lang=us

Hey Candee, 

 Nice work! I was reading an article and it was describing the second image as partial placenta previa and the other as a complete placenta previa. Thank you for introducing me to the knew knowledge. There are so many terms that represent the same thing, so the more familiar we all can be with them the better. I am curious if a mother diagnosed placenta previa causes stress to the fetus in anyway? What do you think?

Hi Candee,

I like the image you included! The other types of previa are low lying and partial/Marginal. partial will be partially covering the internal os but won't be attached on both sides. 

https://www.mayoclinic.org/diseases-conditions/placenta-previa/diagnosis-treatment/drc-20352773

I found this website and it explains how there "treat" the patient based on bleeding levels. 

What do you think would happen if a baby had placenta previa but they tried to do a vaginal birth?

Hi Candee,

I love the picture you included in your response. It really helps lock in the concepts for a visual learner like myself. I think that the other previa you are talking about is marginal previa, in which the placenta begins to grow at the bottom of the uterus and pushes against the cervix without covering it. 

https://www.healthline.com/health/placenta-previa#types

Hi Molly!

Thank you so much for sharing that video, that was the best explanation of placenta previa I have seen! The presenter did a great job breaking down all of the different components that can lead to a previa and taught me some new vocabulary! I kept hearing the word "antepartum" but had no clue what that meant, but according to the video it refers to 20 weeks or greater of the pregnancy. I also liked that she mentioned the different causes, some of which I was familiar with, and others were completely new. She mentions that mulitple gestattions, hx prior placental previas, and even hx uterine surgery.

Here's a cool article that shows placenta previa across a range of modaliities, I thought you might like this with your background in MRI :)

https://pubs.rsna.org/doi/full/10.1148/rg.295085242

Hey Ms. Molly, 

 Thank you for sharing this video! Khan Academy is a great resource to use the when we need a little more help creating a visual. I think it is interesting the placenta usually favors the fundus region, I read that too. Do you think it is because as the baby grows it just tends to cause the placenta to migrate upward? I'm curious if how the baby grow affects where the placenta migrates. 

Howdy Molly,

Khan Academy is great! I try to keep reminding myself that the placenta has two parts: mom's (decidua basalis) and fetus' (frondosum). So here I am reminding everyone again!

I answered "no" when asked if the placenta moves but I think you're right! We can technically answer yes. Although, if it were to truly move both mom and baby would be in trouble. I think the blastocyst would have to implant quite near the cervix for previa to occur (since the uterine growth tends to move it superiorly). 

A fun side note about placentas I learned in clinic today: placentas tend to get old and end up with calcifications toward the end of pregnancy. This is totally normal!

Sarah

Hey Monica, Britt also helped me discover vasa previa which I believe is another form of obstruction. This condition will be when there are blood vessels blocking the cervical canal. That's so funny that you added the fact about baby bumps because we also have that superstition in my family. Maybe it's true that boy zygotes like to implant lower in the uterus compared to males. I wonder if that's a thing. I tried researching but couldn't find anything LOL! 

Hey Monica,

I love how you included the reward of sonographers being honored with role of assessing placental location. Such a dope perspective! 

Also when you say other organ in the second paragraph what do you mean? The baby?

Pregnancy superstitions crack me up too! What is funny is I was taught the exact opposite; when the baby is round like a basketball and sits up it's a boy and then when the baby hangs low it is a girl. Too funny!

Hi Monica, 

I love how well you explained everything! Also that superstition... I never fail to hear it when I see someone's baby bump!! You're right, it could all just be where they implanted! 

Today at my site I scanned another 5wk gestational sac (this time with yolk sac!) and it was implanted more on the left side of the uterus. As my instructor and I examined the ovaries, wouldn't you know it?? The corpus luteal cyst was on the left side. I wonder if the ovaries make it more likely for implantation to happen on the same side as where the egg was released, or if it really is just totally random.

Karen

Hey Ms. Chrishawna! 

Great response! I like how you highlighted the importance of dedicated patient care because it is sooooo true! The slightest change in measurements can save a life. Also I enjoyed the images of umbilical cord insertion. Is important to stay open because anatomy does vary from patient to patient. Also I have been seeing my CI use color to asses perfusion to the fetus. I know we all were initially taught not to put color on the baby, but at the 20 week fetal ULS there a few instances in which color would be used. Additional examples include: kidney's, umbilical arteries, and placenta. Just a friendly reminder NEVER put color on the heart. 

You are totally right Chrishawna! We must take the time and care necessary to help set up good patient management for mom. As Dr. Wilson mentioned in the lecture, we should evaluate a borderline low lying placenta pre and post void to see the true placental location relative to the cervix. An over distended bladder can push the placenta closer to the cervix.

 This website, RadiologyKey, describes a few more scenarios that can cause a false flag for placenta previa. 

Here is one scenario that Radiology Key describes. The top image shows a contraction of the myometrium (**) mimicking the cervix and placenta previa. The bottom image shows the uterus after the contraction.

Hi Chrishawna!

Great answer and picture! I literally saw a placenta previa today in clinical and it just made me that much more aware of how important it is that we scan the placenta and cervix. I also learned that the mother could be having a contraction that could falsely make it look like placenta previa, so if you see possible placenta previa in the beginning go the exam, check again towards the end to see if it is true previa or possibly just a contraction.

This is huge! Thank you for mentioning this. As sonographer we definitely look at, not only where the umbilical cord enters baby, but also where it enters the placenta. There are several pathologies around this concept. Which area of insertion is considered normal?

Hey Chrishawna,

Thanks for the image of the cord location. I am having a bit of trouble understanding the different variations. I did find that velamentous cord insertion is where the cord inserts on the edge of the placenta along the chorioamniotic membranes. This makes the blood vessels unprotected as they leave the placenta until they reach the umbilical cord where they are protected. Here is an image I thought was representative of the unprotected cords. It also highlights vasa previa which is where those vessels can get trapped making them at risk for rupture.

Hey Allison!

I really liked the visual you provided of possibilities the placenta can be located. As a visual learner that helps me a lot! Thank you!

Watching the video you posted made curious if the hypoxia, on the fetal end of placenta previa, was because in the cephalic position the head is essentially hindering perfusion of oxygen between mom and fetus? What do you think?

Hi Allison,

We had similar answers! I really like your image you included, it's different from everything I've seen! Do you think theres any treatment for placenta previa? 

Hi Allison!

I loved how in depth you went about the three categories of low lying placenta. I kind of glossed over it as a whole "close to cervix" placental location but from what you wrote, you can really tell that minute differences in location can really matter!

I also love the visual you used. It's crazy to see how much the uterus balloons up in relation to mother's body, when the uterus generally starts at only about the size of a fist!

Thanks,

Karen

Hi Allison!

Thank you for including the photo, it helped me wrap by head around the different placenta positions, since it is a bit confusing with all the variations. The way you explained the reason for possible bleeding with a placenta attached to the lower uterine segment made sense to me because I was having a a little trouble understanding it. But it makes sense that it  could disrupt the blood vessels as the uterus continues to grow. I liked this image because it clearly labels everything and it helps fuse together the diagrams and ultrasound images!

Hi Nailah!

You bring up another dangerous condition; placental abruption. While we haven't discussed this in lecture yet, I found this nice little graphic which explains some of the differences between placenta previa and placental abruption. They can both present with vaginal bleeding, however there are some big differences to look out for.

For example, with placenta previa the bleeding is typically painless and the blood is a bright red color. With placental abruption, there is pain with the bleeding and the blood is a dark red color. These may be important signs to look out for on a patient's chart so we know what we will be seeing when we scan!

Hope you had a good day at clinicals :)

Hi Alexis!

Thank you for sharing that video you posted. I honestly didn't know 90 percent of the time placenta previa resolves in the third trimester. I guess I assumed it remained throughout pregnancy if it was present at the 20 wk ULS. This article does not necessarily say 10 percent but it does essentially state that the percentage of placenta previa cases significantly decrease in the third trimester.

https://www.parents.com/pregnancy/complications/health-and-safety-issues/all-about-placenta-previa/ 

Hi Alexis!! 

It's so cool how the placenta moves along with the uterus. I found that the the location of the placenta can be sonographically imaged inaccurately if or while the mother is having contractions! The contractions can make it look like the placenta is laying low, near the cervix. I wanted to comment on yours, because I noticed that you listed all of the positions of the placenta ( super helpful btw ) and wanted to make note on how we should always be aware and ask the mother questions to make an accurate diagnosis. 

Thank you for sharing! 

Hey Raminita, 

 I really appreciate the visualize you provided, visuals are always so helpful. I like how your example provides a reminder that placenta previa can occur whether the fetus is breached or vertex. Congrats on finding the cervix too! That's amazing!!! I know it is still all knew for us, but do you have any tips on locating the cervical canal in pregnant women?

Hi Raman! That's awesome you got to see what we're learning in class in real life!

Regarding the uterus growing and hopefully taking the placenta with it away from the cervix, I found the below image on RadiologyKey. It shows how the placenta went from being a complete placenta previa to marginal placenta previa over 6 weeks. This shows how follow up with these patients is important!

THANK YOU for talking about the thickness of the placenta! As a student, I had a case where I noticed the placenta looked abnormally thin. The placenta was measuring only 1cm thick and during the exam, the patient was telling me she had fainted twice since becoming pregnant, but no one could tell her why. At the end of the exam I told the tech I was working with that I thought there was something wrong with the placenta. She assured me that the thickness of the placenta didn't really matter and that it could vary... I still didn't feel right. I asked several other techs and they all said something similar. THANKFULLY Michelle works at the site I was at so I was able to ask her. She agreed with me that something wasn't right and was able to call the reading physician to make a note of the finding. 

This was something that maybe wasn't having too much of an impact at the moment, but could have put mom and baby at risk down the line. This is one of those times when you realize that it is SO important to look and everything even when it's easy to get complacent. 

Thanks Raman!

Hey Hailey,

great job!

I saw that both your images show a more anterior placenta previa. I found some images that show placenta previa both anterior and posterior. 

This first image ^ shows an anterior placenta previa that covers the internal os of the cervix

This image shows posterior placenta previa where the placenta covers the internal os of the cervix.

I didn't realize this was something to be noted until looking at images. Then I thought is one worse than the other? I found this study that shows if the placenta is more anterior it is more likely to migrate upward than a posterior placenta. The study shows a mean migration rate of 2.6mm/ week for an anterior placenta previa as opposed to a posterior previa that has a mean migration of 1.6mm/ week.

Here is a link to the study if anyone is interested!!

https://pubmed.ncbi.nlm.nih.gov/18067142/

Hey there Hailey ! 

 Thank you for sharing those images, they are great, very clear examples of placenta previa. You response in which you said a placenta lying within 2cm is not as worrisome made curious. I’m wondering if the size of the baby can affect this at all? I’m curious if a big baby being pushed through that cervical canal can potentially cause hemorrhage even if it is two centimeters. What do you think ? 

Hi Sarah!

Great post! I also watched the same video earlier this evening and loved how it was straight to the point with sharing key concepts. I love how you added the measurement of 2cm or less being a concern if that's the distance from the placenta to interal os of the cervix. 

I also found this short video that helps further evaluate on placenta previa that I found to be of help. 

Hi Sarah!

Thank you for sharing that video clip, I love videos that are straightforward and provide a clear understanding of the concept! One thing I found interesting about it was the causes of placenta previa. It mentioned a possible reason that implantation did not occur in the uterine fundus and thus resulting in a placenta previa could be due to fundal vascularity. It totally makes sense if the mother has had prior c-sections or uterine surgery, but it was the first time I heard anyone mention it! After all, we know the uterus needs to be highly vascularized to sustain a healthy pregnancy!

Hi Sarah!

I love your straightforward explanation! I agree that placenta on or near the cervix can be a big issue. However, did you happen across any studies on anterior placentas? What I've found were very contradicting on whether it would pose any extra risk to fetus. What do you think?

Karen

Hey Sarah, 

Great response! I appreciated how you brought up the chorion frondosum. I recall coming across that in the lecture and my research as well. I’m still trying to connect the chorion frondosum and the chorionic villi together though. Are the chorionic villi essentially projections of the chorionic frondosum ? Curious to know your thoughts on this. 

Hi Sarah,

You always have such clear explanations, I love it! As a fellow visual learner, the video you shared was super helpful, and I like how it explained the different potential causes of placenta previa. It got me wondering... is there any difference in the maternal experience with placental placement? Anterior placement makes it harder to feel fetal kicks, but does a particular placement provide less discomfort for mom?

I started researching, and found  this article that states women with anterior placental placement are more likely to have lower back pain. I wonder why that is? Maybe because the baby's "anchor" is farther from the maternal midline and puts more counterweight on the lower back? I suspect it may all be equally uncomfortable by the time you reach the end of the 3rd trimester.

This article also noted that an anterior placenta may make a c-section riskier because the incision is more challenging.

Hi Karen! I love this image you posted, Allison just brought to my attention the different positions of the placenta, what position do you think would be best?

Hey there Karen !

 I love those images! Too cute ! It’s interesting you brought up anterior placenta. I mentioned that in my response as well. I’m sure an anterior placenta may not be consider as great of a risk as placenta previa; but I wonder is this form of placental placement places a mother’s pregnancy in the high risk category as well? What do you think ?

Hi Hailey and Nailah!

I've looked and looked online to see what location for placenta is best, and there is no clear answer besides low lying being bad. Nailah, just like you I saw some articles saying there are risks for anterior lying placentas, but as I did more research, I saw that there are just as many articles trying to debunk it! Now I don't quite know what to think. This may be a great question for Dr. Wilson come class time!

Thanks ladies!

Karen

Hi Karen,

Great visual! I remember someone telling me that if the placenta is placed anteriorly, you are less likely to feel fetal kicks, which makes sense. A quick Google search [here] confirmed that fetal kicks are often felt much earlier in cases where the placenta is placed posteriorly. It also noted the added benefit of posterior placenta in that the fetus can grow in better alignment with the birth canal. Are there any different benefits to having an anterior placement?

Hi Karen! I love these pictures so much, they're so cute! I also learned that previa will be an indication of C-section for the mom and as you mentioned could be very dangerous for the mom and baby. Super important for us to document accurately when taking our images.

Hi Karen! I love how simple your images make the different positions! I thought from the lecture though that low lying placenta was a subcategory of placenta previas and not all low lying placentas create a marginal or complete previa... please correct me if I am wrong! If they are within the 2cm from the internal os, will they always have at least a partial coverage?

Thanks for any clarifications guys :)

Howdy Lauren,

That's an excellent explanation of placenta implantation!

With all this talk of implantation/mechanisms I've been slipping on some basics! So, I like to remember (from last quarter) that the area of the uterus that connects with the fallopian tubes is called the cornua. Implantation closer to the cornua is better (since this means the placenta will be further from the internal os of the cervix.

Here's a quick reminder!

Sarah

Hey Lauren, 

I enjoyed your response, great job! I like you how you took it a step further and mentioned how an overly distended bladder can essentially create a false positive for placenta previa. Do you understand how though? This image 

makes me think a filled bladder pushes upward, creating the illusion the placenta covers the cervix. What do you think?

Hi Lania!

Thanks for sharing your clinical case! I haven't seen an OB patient with a placenta closer to the cervix yet. How soon did they schedule the patient for a follow up? I wonder how soon it is decided that the C-section will have to take place, how much time they will give the placenta to move further away from the cervix?

I found this image, showing a C-section through the placenta, I wonder if this is similar to how the patient in your case would have it performed?

Hey lania, 

 You worded your response really well! Great job! I am glad you are getting experience with OB at your site. Are you noticing at your site that beyond the 20 mark and as the baby gets bigger, their anatomy becomes more difficult to recognize? 

Hi Lania,

Thanks for sharing your clinical experiences! I am wondering if you were familiar with this patient's history? Do you know if this was her first pregnancy, or if not has she had a history of placenta previa with other pregnancies? Hopefully she gets good news at her follow-up exam!

Hi Lania!

Thanks so much for sharing your clinical story! I asked my CI the same thing, along the lines of "What can a PT do if they have placenta previa?" and he gave me the unfortunate news that there's nothing you can do to move the placenta around. I can't image if you guys missed that and the mother went into labor. I've heard stories of mothers being in labor for > 12 hours and just ended up in a c-section. 

Our career is so rewarding! We must be vigilant for doctors to safely deliver these babies!

Hi Paris,

That's a great question! I am wondering if a translabial imaging technique might be helpful in this instance? I remember Dr. Wilson mentioning in this weeks lecture on the Cervix that it provides us an in depth look at the cervix without the invasiveness of a transvaginal exam! I'm sure there are more ways to evaluate, but this was the first thing to come to mind!

Hi Paris!

Great question. Perhaps you could ask the mother to walk around (if it's safe for her to do) and see if this would cause the baby to move positions?

I remember when I was shadowing there was a case like this where the baby wasn't in a good position to get a good images and the tech made the mom walk around the building and even do squats!

I don't think the mom was thrilled about having to do exercises... but the baby did end up moving positions :)

Hi Paris! I saw this and had to comment lol, I want to say translabial because at my site, the tech I was following told me to start an OB my first week even though I had no idea what I was doing. I knew I had to find the cervix because I had watched it before that so i went looking. Shocker... I couldn't find it. The tech came and she also couldn't see it! She ended up doing translabial and got a beautiful image.

Hi Paris!

I found this article that explains some possible options to visualizing the cervix since it may become more difficult to visualize it as the third trimester approaches. It mentions options like external fetal manipulation, overdistension  the maternal bladder,  and Trendelenburg position, as ways to better visualize the cervix, however it also says these options may distort the cervix. and also obviously be uncomfortable and not ideal for the patient. The article explains results of a study done of the effectiveness of transperineal ultrasound in cervix imaging, here is a quote with some results:

"The entire length of the cervix was seen in 136 (86%) of the 158 patients scanned transpenineally. In the remaining 22 patients, the internal os and upper portion of the cervix were successfully visualized, but the external os and caudal portion of the cervix were not seen because of shadowing from gas in the adjacent rectum."

So it definitely seems like a great option when it is difficult to visualize transabdominally! 

https://www.ajronline.org/doi/pdf/10.2214/ajr.157.1.2048542

Hi Paris!

At my clinical site, we are constantly asking the momma to be to move LPO to RPO if the baby isn't in a good position to find the best represented image during the scan. If the baby still stays within that same position, we may also have the mother use the bathroom or walk up and down the hall for 5 mins. Once the mother returns from the bathroom/ walk, the baby's position typically changes and it accurate for imaging. 

Thanks for that challenging question! You can never NOT learn something new with this modality! So many tips and tricks to learn, I love it!

Hi Paris! This was a great question to get us thinking! I would first maybe have the mom walk around the office for a few minutes to see if this possibly changes baby's position. If this doesn't work then I would most likely resort to an Endovaginal exam to get a better look at the cervix.