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Is The Scar Of The C-section Scar Being 1.7 Considered Dangerous?

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Posted on Sat, 1 Oct 2016
Question: Hi Doctor,



my wife is 25 years old, pregnant at 36 weeks and 3 days. Her last period was on December 31st. our first visit to Obstetrician was when she was 7 weeks and based on her last period date and ultrasound her expected due date is 4th of October 2016

We have one son who was born in 31st of September 2014, she gave birth with c-section when she was 36 weeks, the c-section was emergency c-section because she developed Hydronephrosis and according to NST they saw fetal heart stress.


Coming back to her situation now, she visited OBG couple of times because she had painful Irritable Uterus, at 32 weeks she couldn't feel the baby move for almost whole day so we went to OBG immediately and the OBG said the baby heart is ok and she put her on NST which showed normal and the baby started to move later.

at 33 weeks we went for another visit which showed 3rd-degree calcification of the Placenta, the Doctor said to visit her every once a week to make sure if the calcification is not getting worse. she told her to stop VitD, Calcium Supplement as that could make it worse. The baby growth was normal and according to the gestational age. The Doctor gave her Primolut depot injection and nifedipine to help her with painful non-stop contractions of the Uterus but still it's not helping much .

at 35+ (about 5 days ago) weeks we went to see an OBG Specialist, which checked on the baby movements which seem normal, she then sent us to a Specialist ultrasound Doctor to check for fetal growth,Umbilical cord doppler and C-section scar tissue thickness, The doctor told us she requested this ultrasound so she can be sure if the placenta calcification is affecting the baby development of if the baby is recieving enough blood supply. The report of the ultrasound showed an overall normal fetal growth, normal AVI and normal blood supply to the fetus from the umbilical cord. However the C-section scar tissue thickness was only 1.7
When we took the results to the OBGN Doctor, she told us that the Scar is quite thin and she wouldn't suggest to do VBAC because of the risk of uterine rupture, she rather suggested us to do C-section at 38 weeks that's at 18th septmeber 2016.

Now she is 36+ weeks she will be 37 weeks on Saturday. her chief complaint so far is painful non-stop contractions that comes back every 10 (at 35 weeks it was every 15 minutes) the contraction continues for 44 seconds and in some occasions for 2 minutes, she said she couldn't feel the baby move for a while, i told her to drink something sweet and lie on her left which luckily helped her and now the baby is moving normally.

I asked the Doctor if she can suggest us anything for this Irritable uterus but she said there is nothing much to help with this but only cope with it. nifedipine could help but she wouldn't suggest to give it at the moment as she is already 36+ so risk of preterm labor is no longer there

My questions.

1. Is the scar of the c-section scar being 1.7 considered dangerous? could she continue her pregnancy until 38 weeks (previous c-section was at 36 weeks) or is there a risk of uterine rupture before that?
2.Is this thickness (1.7) normal or acceptable at this stage of pregnancy having a previous c-section?
3.What signs should we look for to run to emergency in case of rupture?It scares me alot to imagine she could have uterine rupture.
4.Does the irritable uterus (or continues contractions) she has increase her risk of rupture?
5.do you agree witht the Doctors plan ? and what do you suggest ?



this is my second time asking about my wife condition at Healthcare magic. as we are very concerned.







Thank you
doctor
Answered by Dr. Timothy Raichle (3 hours later)
Brief Answer:
See multiple answers below...

Detailed Answer:
Thank you for again turning to us for help in interpreting this advice. You have very valid concerns and I am happy to help you again. After the answers below, I have outlined a possible plan that I might suggest to a patient in a similar situation.

First, here is an excerpt from a reliable source regarding the evaluation of the uterine scar with ultrasound:

"There is no myometrial thickness threshold value that performs well enough to use in clinical practice to predict whether a hysterotomy scar will rupture or remain intact. A 2013 systematic review of 21 studies of sonographic lower uterine segment thickness for predicting the risk of a uterine scar defect during a trial of labor could not determine an ideal cut-off. The authors concluded a full lower uterine segment thickness (distance from bladder wall to amnion) cut-off of 3.1 to 5.1 mm was reassuring that the scar would remain intact during a trial of labor; at this cutoff, however, sensitivity for the occurrence of a uterine defect (dehiscence, rupture) was only 96 percent (95% CI 0.89-0.98) and specificity was only 63 percent (95% CI, 0.30-0.87). When the minimum myometrium-only thickness overlying the amniotic cavity at the level of the lower uterine segment scar was 2.1 to 4.0 mm, sensitivity was 94 percent (95% CI 0.81-0.98) and specificity was 0.64 (95% CI 0.26-0.90).

At least one case report has described a catastrophic uterine rupture with complete extrusion of the fetus and placenta and neonatal acidosis in a woman whose sonographic lower uterine segment measurement exceeded 3.5 mm. Thus, ultrasonic measurement of the lower uterine segment in late pregnancy is far from being either predictive or protective of catastrophic uterine disruption.

So, the conclusion here is that a thicker scar might be more reassuring, but it is not predictive of uterine rupture in a thin scar such as that seen with your wife. Following are your questions with my answers.

1. Is the scar of the c-section scar being 1.7 considered dangerous? could she continue her pregnancy until 38 weeks (previous c-section was at 36 weeks) or is there a risk of uterine rupture before that?

While this thickness is not reassuring, it is NOT predictive of risk of rupture. Yes, there is a risk of uterine rupture BEFORE the onset of labor (labor is defined as uterine contractions that are changing the cervix).

2.Is this thickness (1.7) normal or acceptable at this stage of pregnancy having a previous c-section?

There is no 'normal' value. See answer to question #1.

3.What signs should we look for to run to emergency in case of rupture?It scares me alot to imagine she could have uterine rupture.

Yes, this is very scary. Signs that something is not right would include pain that does not go away, specifically above the pubic bone under the prior site of her prior Cesarean Section incision.

4.Does the irritable uterus (or continues contractions) she has increase her risk of rupture?

No-one knows for sure, but these persistent contractions will certainly lead to thinning of the lower part of the uterus (near the Cesarean Section incision) and possible increase the risk of a uterine rupture.

5.do you agree witht the Doctors plan ? and what do you suggest ?

We normally plan a repeat C-section at 39 weeks. We perform these earlier if we are concerned about labor or unexplained pain. We might also consider doing the surgery sooner if there is any concern about the baby. I might propose the following plan to a patient in a situation such as yours (and I have done this before):

1. I would recommend an amniocentesis to test for fetal lung maturity (this can be tested from the amniotic fluid and is quite easy with ultrasound guidance)
2. If the lungs were mature, then I would proceed with the C-section
3. If the lungs were immature, then I would give a shot of steroids to mature the lungs and then perform the C-section at 37-38 weeks

Tell me what you think.
Dr. Tim




Above answer was peer-reviewed by : Dr. Arnab Banerjee
doctor
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Follow up: Dr. Timothy Raichle (44 hours later)
Thanks Doctor for the well-detailed answer.

The Doctor suggested us to take steroid injection for my wife, i think it's called Dexamethasone or Betamethasone don't remember the actual name, we are planning to do the injection Sunday as she will be 37 weeks and the c-section is scheduled at 38 weeks (next Sunday 18th September) , The doctor suggested us to have this done from now so the baby lung can be mature enough during this one week.

Doctor, I want to share with you that me and my wife and including my parents are considering to let my wife try normal birth or as known as VBAC. as there is no cut-edge research that could actually suggest there is an actual risk neither is there any normal value for the c-section scar thickness or thinness. My parents who have the old thinking are telling me that our Doctor is going for making money out of the c-section as that's more costly compared to normal birth, they both think the Doctor is just pushing us to an unnecessary thing (we are paying for the surgery as I'm outside home it's not free here) .

What do you think Doctor? Do you believe that a c-section scar of 1.7mm is rather risky to try for normal birth ? or you wouldn't mind trying since there is no clear research that suggests a 1.7mm scar is on the riskier side.

Have you seen any case that had thin scar (about 1.7mm) that had normal delivery during your experience ? what's the guideline in USA for VBAC?


Thanks again

doctor
Answered by Dr. Timothy Raichle (1 hour later)
Brief Answer:
Possibly a candidate for VBAC but there are concerns...

Detailed Answer:
Welcome back,

In terms of the reasons for the prior C-section, it was not really because of a 'failed' trial of labor. In that sense, she is probably a good candidate for a VBAC. That being said, there might be enough concern about the prior uterine scar that a repeat C-section is a better idea. Certainly her OB's have a better sense of what is going on than I do, but hopefully this answer will help. There is no guideline related to uterine scar thickness in the USA and this is based on the uncertainty in predicting who is at risk for a uterine rupture. That being said, I was able to find the following statement regarding the 'lower uterine segment' thickness and what is 'normal':

"The 10th, 25th and 50th percentiles of lower uterine segment thickness are about 2.0 mm, 2.3 mm and 3.2 mm, respectively, near term."

So, your wife's lower uterine segment at the site of the prior scar is less that the 10th percentile in terms of thickness. If I were trying to make a decision about her case, I would argue that there is an unknown risk but the scar appears 'thinner' than normal, she is contracting quite a bit without going into labor, and there is concern about an increased risk of uterine rupture.

I think that I like your doctor's plan and agree with their decision making in this case.

Dr. Tim
Above answer was peer-reviewed by : Dr. Arnab Banerjee
doctor
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Follow up: Dr. Timothy Raichle (21 minutes later)
Appreciate the quick response Doctor,

Yes I have read ew researches on PubMed as well and like you said there is no clear margin of who is at risk and who is not, but overall it's to some degree agreed that the thinner the riskier and my wife is on the thinner side.

Yes, the contraction has increased even more now, she uses an app to check the time between contractions and the last two days she has contractions every 7 minutes and the time of contraction is about 40 seconds. She is also complaining of slight lower abdominal pain near the pubic area that comes and goes, it got me worried it could be a pain from the scar, however when I press on the scar area she doesn't feel any pain. i think the pain could be due to the baby head being lower than usual or engagement pain?

I will take her to the Doctor tomorrow and do the injection of the steroid as suggested.

Thanks again Doctor, your responses are always reassuring and informative
doctor
Answered by Dr. Timothy Raichle (4 hours later)
Brief Answer:
There is a good plan in place.

Detailed Answer:
Either steroid mentioned is appropriate for maturing the fetal lungs. The way that these work is by stimulating the release of a protein called surfactant. This substance helps to keep the airway open so that adequate gas exchange can occur.

The greatest benefit of the steroid occurs 24 hours after the last shot is given and up to 7 days. Given this fact, I think that your doctor could consider the following:

1. Go ahead with the steroid injections
2. 24 hours after the last shot, if she is having any persistent or significant contractions, then just go ahead with the C-section. It is perhaps not necessary to wait until 38 weeks.

Regardless, you have a good plan in place and the doctors are definitely responding to the situation.

I truly wish you and your wife the best of luck!
Dr. Tim
Above answer was peer-reviewed by : Dr. Veerisetty Shyamkumar
doctor
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Follow up: Dr. Timothy Raichle (19 hours later)
Hello Doctor,

We went to the Doctor today, she didn't check that much on the ultrasound regarding the third degree calcification of placenta as it seems like she wasn't much concerned about it.
She checked the AFI which showed to be at normal level
She checked the Cervix and she told us it was 1cm, i remember last week (04/09/2016) it was 3.4cm now it reduced to 1cm.
She also checked on the baby head and she said it's very low and looks engaged with the cervix.

We did the Dexamethasone injection 12mg (8mg per 2ml) so she she gave us a 3ml injection.
We booked the c-section on 18/09/2016 so that's in about a week from now.

The contractions still remain the same in an interval of 5 to 7 minutes between each contraction and a contraction that lasts about 40 seconds.
The Doctor told us these contractions doesn't seem to be worrisome because if that contractions was real and it continued for that long (3 days now) then by now we would have the baby by now.

Few questions.

1. I uploaded the pictures of the ultrasound we did on 04/09/2016, please have a look and give us your comments on it, specially the placental calcification and the scar thickness.. what do you reccomened based on the ultrasound?.

2.the Cervix has decreased to 1cm,does that mean there is chance for vaginal delivery before 18th of septmeber (C-section date), specially that my wife now mentions some very painful feelings from the low inside (i assume the cervix) she is saying it's a pain that feels like baby pushing specially when the baby moves?

3.If a scenario happens that she gets real labor contractions and her cervic dialates to some degree before 18th of september would you rather wait for vaginal delivery to happen or you would opt for emergency c-section?
I'm asking this because me and my wife are thinking to ask the doctor to wait for about 2 hours to try normal labor before they will decide to do emergency c-section incase we run in that scenario...


Thank you again Doctor, truly appreciate your patience with us
doctor
Answered by Dr. Timothy Raichle (49 minutes later)
Brief Answer:
I have a question for you...

Detailed Answer:
Did your doctor by any chance put her on the monitor to see if she can see the contractions? Has she ever been put on the monitor?

Dr Tim
Above answer was peer-reviewed by : Dr. Raju A.T
doctor
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Follow up: Dr. Timothy Raichle (56 minutes later)
She wasn't put in Monitor at this visit, the last time she was put in monitor when she was 33 weeks and the monitor ran for 20 minutes, according to the doctor at that time she didn't see any alarming uterine contractions.
If you suggest that we can request the Doctor to do that tomorrow, we are going to the hospital tomorrow for the second dose injection of Dexamethasone.

Thank you.
doctor
Answered by Dr. Timothy Raichle (4 hours later)
Brief Answer:
She needs to be monitored for labor

Detailed Answer:
Labor is defined as regular contractions that are changing the cervix. If I had a patient who had a prior Cesarean Section, who was contracting regularly, and who had shown signs of labor (a change in the effacement of the cervix from 3 to 1 cm), then this would be enough for me to go ahead with the C-section. Given that she is significantly less than 39 weeks, I would also go ahead with the steroid injections and then perform the C-section 24 hours after the second shot if she was still having regular contraction activity.

Placing her on the monitor is useful in terms of the following:
1. Confirming that what she is feeling are measurable contractions in terms of frequency and duration
2. Making the argument for going ahead with the C-section

As stated before, the ultrasound is not predictive of uterine rupture. Given how much she is contracting, it is not surprising that the lower part of the uterus is thinned out. My gut feeling in a patient such as your wife would be to go ahead and perform the C-section in a NON-urgent setting. Consider that the risk of uterine rupture is almost certainly increased in the setting of a prolonged labor. Given that she has basically been in some form of early labor for a long time with nothing to show for it is reason enough to move towards delivery.

Dr. Tim
Above answer was peer-reviewed by : Dr. Veerisetty Shyamkumar
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Is The Scar Of The C-section Scar Being 1.7 Considered Dangerous?

Brief Answer: See multiple answers below... Detailed Answer: Thank you for again turning to us for help in interpreting this advice. You have very valid concerns and I am happy to help you again. After the answers below, I have outlined a possible plan that I might suggest to a patient in a similar situation. First, here is an excerpt from a reliable source regarding the evaluation of the uterine scar with ultrasound: "There is no myometrial thickness threshold value that performs well enough to use in clinical practice to predict whether a hysterotomy scar will rupture or remain intact. A 2013 systematic review of 21 studies of sonographic lower uterine segment thickness for predicting the risk of a uterine scar defect during a trial of labor could not determine an ideal cut-off. The authors concluded a full lower uterine segment thickness (distance from bladder wall to amnion) cut-off of 3.1 to 5.1 mm was reassuring that the scar would remain intact during a trial of labor; at this cutoff, however, sensitivity for the occurrence of a uterine defect (dehiscence, rupture) was only 96 percent (95% CI 0.89-0.98) and specificity was only 63 percent (95% CI, 0.30-0.87). When the minimum myometrium-only thickness overlying the amniotic cavity at the level of the lower uterine segment scar was 2.1 to 4.0 mm, sensitivity was 94 percent (95% CI 0.81-0.98) and specificity was 0.64 (95% CI 0.26-0.90). At least one case report has described a catastrophic uterine rupture with complete extrusion of the fetus and placenta and neonatal acidosis in a woman whose sonographic lower uterine segment measurement exceeded 3.5 mm. Thus, ultrasonic measurement of the lower uterine segment in late pregnancy is far from being either predictive or protective of catastrophic uterine disruption. So, the conclusion here is that a thicker scar might be more reassuring, but it is not predictive of uterine rupture in a thin scar such as that seen with your wife. Following are your questions with my answers. 1. Is the scar of the c-section scar being 1.7 considered dangerous? could she continue her pregnancy until 38 weeks (previous c-section was at 36 weeks) or is there a risk of uterine rupture before that? While this thickness is not reassuring, it is NOT predictive of risk of rupture. Yes, there is a risk of uterine rupture BEFORE the onset of labor (labor is defined as uterine contractions that are changing the cervix). 2.Is this thickness (1.7) normal or acceptable at this stage of pregnancy having a previous c-section? There is no 'normal' value. See answer to question #1. 3.What signs should we look for to run to emergency in case of rupture?It scares me alot to imagine she could have uterine rupture. Yes, this is very scary. Signs that something is not right would include pain that does not go away, specifically above the pubic bone under the prior site of her prior Cesarean Section incision. 4.Does the irritable uterus (or continues contractions) she has increase her risk of rupture? No-one knows for sure, but these persistent contractions will certainly lead to thinning of the lower part of the uterus (near the Cesarean Section incision) and possible increase the risk of a uterine rupture. 5.do you agree witht the Doctors plan ? and what do you suggest ? We normally plan a repeat C-section at 39 weeks. We perform these earlier if we are concerned about labor or unexplained pain. We might also consider doing the surgery sooner if there is any concern about the baby. I might propose the following plan to a patient in a situation such as yours (and I have done this before): 1. I would recommend an amniocentesis to test for fetal lung maturity (this can be tested from the amniotic fluid and is quite easy with ultrasound guidance) 2. If the lungs were mature, then I would proceed with the C-section 3. If the lungs were immature, then I would give a shot of steroids to mature the lungs and then perform the C-section at 37-38 weeks Tell me what you think. Dr. Tim