Perineal Tear Risk Factors, Preventative Strategies & Surgical Pearls

[Dr. Amy Park]
Tell us a little bit more about those tears. How do they occur? What can we do to prevent them? I think a lot of people don't even realize when they fill out their birth plan that that could even be a possibility. There's forceps, there's vacuum, there's higher order tears. Just tell us what the risks are with all the modes of delivery.

[Dr. Lisa Hickman]
We know that there are some pretty well-defined risk factors for more advanced tears during delivery. Operative vaginal deliveries confer the highest risk. When you put a midline episiotomy in addition to that, it increases the risk even more. Larger babies, typically in studies, it's more than 4,000 grams at the time of delivery. Occiput posterior position because the fetal head diameter is increased. Asian ethnicity is actually a risk factor for an increased order magnitude of tear.


[Dr. Amy Park]
You know why that is? That is because it's a shorter perineal body. Speaking from personal research.

[laughter]

[Dr. Amy Park]
I actually didn't know why. Then it just has to do with just the anatomy of it. It's a safety zone. If it's 8 centimeters, you probably aren't going to have a fourth-degree tear. You know what I mean? If it's two and a half.

[Dr. Lisa Hickman]
Right. Two and a half and less has been what's typically quoted. Yes, if there's less anatomic distance to traverse before you're in the anal sphincter complex, then you're more likely to have the tear first, definitely.

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[Dr. Amy Park]
What are things we can do to prevent it? Sometimes things just happen, right?

[Dr. Lisa Hickman]
Right.

[Dr. Amy Park]
Is there anything we can do to prevent these higher magnitude tears or levator avulsion during childbirth or whatever? What are the things we can do to prevent this? Do some more core, look at pilates and bar or what?

[Dr. Lisa Hickman]
I think having pelvic floor awareness is a really interesting concept. I don't have any data to support that, specifically, but the physical therapist will talk about proper pushing mechanics.

That's something that we-- when I send patients in pregnancy to physical therapy, something that I'll tell them that they can work on with their physical therapist. As far as what research studies have been done in the past to look at reducing severity of tear, we know there are a few things. Perineal massage, patients can do that starting in the third trimester. You have to do it pretty regularly, but the idea is that you increase the elasticity and the stretch of that tissue. It's a little bit more compliant when it comes time to have a vaginal delivery.

Warm compresses and labor have been shown to reduce the risk of having a higher-order tear. I know when I was a resident, there was a lot of focus on perineal supporting the perineum during pushing and during delivery. There's a little bit of data on sideline pushing. Then ultimately, if you have someone who you're really concerned that they have maybe a short perineal body at baseline, you could consider doing a medial-lateral episiotomy to offset that trajectory of force away from the anal sphincter complex.

Those are not perfect. They can be more painful. They can be bloodier to repair or associated with wound healing issues. If you're really trying to avoid that vector of force toward the sphincter complex, that's an option.

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[Dr. Amy Park]
I wonder about technique because that's one of the only things you can control during labor pushing and the massage, essentially, which the massage, I don't know if that changed. Mark and I are going to show our age. I don't think the residents did that. You'd have to get midwife or doula to do that probably. I don't even know if the doulas get in there. Do they do that now?

[Dr. Lisa Hickman]
I think it's supposed to be the patient initiating.

[Dr. Amy Park]
How are the patients supposed to do it? They have an epidural a lot of the time.

[Dr. Lisa Hickman]
No, starting at 32 or 34 weeks, doing it at home to really start increasing the-- That is a commitment. You have to be committed.

[Dr. Mark Hoffman]
Well, I think committing to that, understanding the outcome of not doing that or the potential consequences rather. Amy and I are both recovering obstetricians, but I think we probably have many memories burned in our minds of spending a lot of time at the perineum, trying to figure out ways to make it less challenging of a repair for the patient's sake, obviously. I think about all the different ways people told us to protect the perineum and those things.

The other thing that was always holding the perineum almost together, supporting it with a little four-by-four or something else I always was taught to do. I didn't have that many big repairs, but episiotomies were something that we were-- It was definitely in the time where definitely do them and then definitely don't do them. You mentioned that medial-lateral episiotomy. I guess, it's been a long time since I've done obstetrics. Is that something that's been pretty well-established that, in a sense, deviating or changing the angle of the tear is going to decrease the risk of getting a fourth degree? Is that something that's pretty routinely done?

[Dr. Lisa Hickman]
I don't think it's routinely done. I don't do obstetrics anymore, but I will oftentimes counsel women antepartum about who have had advanced tears in the past. It's like, what were your risk factors? I like to categorize them as modifiable and non-modifiable risk factors to understand, okay, what were your risk factors when you had your first delivery with your advanced tear and then what is still going to be a risk factor this time around, and what could we reduce the risk or won't be a concern.

[Dr. Mark Hoffman]
Let me ask you a question with LNDRs. When there's a tear, how much does the actual repair at the time affect outcomes? Occasionally, you guys get called in. It's not really the on-call situation at every place, but certainly, it's something that can be complex. How much do you think the repair at the time impacts the long-term outcome from a third or fourth-degree tear?

[Dr. Lisa Hickman]
That's an interesting question. There has been some data looking at this of who does the repair. Can that affect outcomes? There is some data suggesting that repairs done by midwives on more complex tears can be associated with higher rates of wound complications. That being said, at least at our institution, our midwives do a great job of evaluating the patient, but then we'll call in higher order trainee or physician to do the repair.

I think that, again, those in the labor and delivery room is the least optimal situation. I think it is a shot to definitely do the repair well.

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[Dr. Mark Hoffman]
I want to make sure it's clear. I'm not saying this with any judgment as someone who did a four-year OBGYN residency. I've done my share of deliveries. I think I saw one fourth degree. It just it wasn't something I saw a lot, let alone-- We delivered boatloads and boatloads of babies while we were in residency. It just wasn't something I did a lot when I was in training. When you get out, again, it's just not something you see. What is the rate of third or fourth-degree repair in an SVD?

[Dr. Lisa Hickman]
Depends on what study you look at, I think 4% to 11% is the incidence of a third or fourth-degree tear. I think it also depends, are you at a center that does a high volume of operative deliveries because that certainly increases risk? You're right. the point you're making, Mark, is spot on because we know that there are studies saying that trainees leave residency and don't feel comfortable managing advanced tears because of the infrequency with which they happen, and you're right. If 80% of women have a tear during a vaginal delivery, the vast, vast, vast majority are going to be first and second-degree tears. How do you get good at something that you only do a couple at?

[Dr. Mark Hoffman]
How do you recognize it? How are you comfortable making that assessment to even know? Again, I say this with some distant memories of going, "I don't even know what I'm looking at." Then someone comes and goes, but it's to say, it's not an easy thing.

[Dr. Lisa Hickman]
No, it's certainly not.

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[Dr. Amy Park]
Obviously, we don't want to have more third and fourth-degree tears just for training or what have you. [chuckles] I think prevention is key and we want to do that. It is interesting. If you look and forecast what the training is going to be like for third and fourth-degree tears, it is good for the residents to train and know how to do it, right?

[Dr. Lisa Hickman]
Right. We have opportunities educating trainees on anatomy. We just actually this past week did a urogyn SIM session for all of our residents. I think SIM goes a long way where you use the low-fidelity models of how to repair and what the anatomy is, so people get used to the steps. I think, just giving people the tools and their armamentarium like, "Okay, first, if you don't know what's going on, start with a rectal exam, and then get a sense of the anatomy, get some irrigation or suction, even if you're in the labor and delivery room and then know what to ask for."

I really thought it would be interesting to have like a pick sheet in the labor and delivery room to make it easier for people like, "Okay, we have a third-degree tear, grab the kit, grab the antibiotics with extra tools, and the suture you need," to make it almost a little bit formulaic. Obviously, again, I hope that it comes off with the utmost respect that I have for what obstetricians do because those are really, really complicated, tricky repairs, but to just standardize it and make it easier. I think SIM and just really good foundational knowledge can be really helpful for going a long way with this situation that is not that common.

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[Dr. Amy Park]
I think people naturally go into surgery with knowing or expecting that sometimes things can go wrong. It's intuitive, but I don't think that that's just the same thing with labor and delivery. Then what you're saying about the best practice alerts on the EMR about the pick sheets, about the education, about getting the antibiotics? There's all of these protocols. I know people don't like protocols sometimes because it's formulaic, but I think formulaic saves lives.

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[Dr. Mark Hoffman]
…Set yourself up to succeed, be in the right place, have everything prepared ahead of time. We don't need to be heroes. Just it should be boring and formulaic and just do it the same way every single time.

When there's a variation, when there's something outside of that, you recognize it because it's outside of that norm…

[Dr. Amy Park]
Also, when you're in the thick of things, it's hard to remember all the things that you need. You know what I mean because it's like there's a lot of blood happening. There's a lot of chaos, there's screaming, there's 20 people in the room. Making this as easy as possible in a chaotic situation is key. That's why the SIM for doing obstetric emergencies, the SIM for the beef tongue model for the lacerations, I think is all key. Then just educating the whole team on what to do is also key. I think that these are all little things that very difficult in practice to do.