Wednesday, August 30, 2017

Blocking the Exit


Earlier this month, we had a telephone meeting with a doctor who could probably be described as the expert in transabdominal cerclage. His name is Dr. Haney. Due to my cervical issues this pregnancy, we’re unwilling to consider trying again without a better option than a(nother) transvaginal cerclage. Dr. Haney, who is located in Chicago, appeared to be that better option. For the sake of my record keeping, I’m going to use this post as a place to track what we learned during our two hours on the phone with him.

The Consult

Here’s my best translation of what Dr. Haney told us. I’m not agreeing/disagreeing with anything, just trying to reproduce in my own words what I heard from him. Since this was filtered through my memory/lens, take it for what it’s worth!

The cervix is like a tube or a spindle: there’s tissue around an open canal. Of that tube, 2/3rds of it is up in the abdominal cavity, attached to the uterus, and the last third is down in the vagina. There is a band of tissue at the top of the cervix, the part in the abdomen, that remains tightly closed. During labor, the pressure of the baby’s head, plus contractions, is what forces that band to dilate. But outside of labor, it stays tight. That’s in a woman without cervical insufficiency (CI).

In a woman with CI, the entire column of the cervix dilates from the internal opening downward as the relatively small pressure from the growing baby presses down due to gravity’s impact. As the cervix dilates, bacteria can get into the uterus, and the membranes of the amniotic sac can tear free from the uterus and prolapse out into the cervical canal and vagina.

With a transvaginal cerclage (TVC), a stitch is placed in the lower third of the cervix. Women who have true CI and a TVC will funnel down to the stitch, because nothing has been done to prevent the upper 2/3rds of the cervix from dilating. This means membranes will pull away from the wall of the uterus, and bacteria from the vagina will be able to ascend to the uterus. If I understood Dr. Haney correctly, his position is that women with CI and a TVC will always wind up with chorioamnioitis because of this ascending bacteria. The chorio in turn worsens the chances of survival for their infants. Having had chorio with all three girls, and knowing that Alexis and Zoe passed before birth due to severe chorio, this was a painful reminder of everything that we’ve been through.

With a transabdominal cerclage (TAC), a 2-3 inch incision is opened at the bikini line. A woven fiber band is tied around the cervix at some point in the upper 2/3rds. In my case, Dr. Haney would place two bands. Each band has the strength to support 100-120 pounds, so they could easily support the weight of a fetus, placenta, amniotic fluid, etc. With the bands in place, dilation is impossible. They’re not tied so tight that the cervix is occluded, but they are tied tight enough that the membranes can’t ever prolapse and the cervix can’t funnel. The result of this is that the mucus plug stays in place, the cervix stays long (~4cm) and bacteria can’t ascend from the vagina. The other results: while one can have periods, first trimester miscarriages, and get pregnant “the old fashioned way,” one will have to have a c-section for any 2nd trimester delivery. There is also a risk of uterine rupture as the cervix can’t dilate if contractions occur, and something’s got to give.

Dr. Haney reported a 99% success rate, where success is defined as a live birth, and even mentioned that 92 of 92 sets of twins whose mothers he performed TACs on were born live. He noted that when babies are born before term with TAC in place, it’s due to other issues.

What are my feelings on all of this? 

I agree with the belief that TAC has much higher success rates than TVC, when you define success as live birth. There are numerous studies, most from outside the US, to support this. If we try again, I will have a pre-pregnancy TAC placed with Dr. Haney.  There is no question in my mind about that. Having said that, the “other issues” that cause pre-term deliveries are also very relevant to me, and I’m concerned they were minimized during our conversation. That’s probably because I was talking to someone who specializes in TACs and not the other issues, but I know exactly how this works: any complications I have during pregnancy post TAC my local MFM team will blame on the TAC. The TAC expert will simultaneously assure me it’s not due to the TAC and that I should work with my MFM team.  The end result will be suboptimal because everyone will be busy pointing fingers at everyone else. Cynical much? Why yes, I am.

Next steps

From my point of view, there are two issues that must be addressed before we decide to try for another pregnancy. First, infection. There’s a growing body of literature correlating first trimester miscarriages and failure of genetically normal embryos to “take” after IVF transfer with asymptomatic, chronic endometrial infection. Correlation isn’t causation, and there are plenty of women with term deliveries who also show these markers of infection (related note, I found a study showing a decent percentage of healthy pregnancies in the 36-38 week range have chorio, but no one ever looks for it because there’s no reason to).

Looking at my personal history, I had more than 15 years of recurrent UTIs. They started when I was a kid, a few times a year, and by early 2010, I got them every month or two. I would take my antibiotics each time, the symptoms would vanish, until the next trigger caused the infection to flare up again. In 2010 I was finally referred to urology. The urologist confirmed that there were no structural abnormalities, and then told me that in some people, the bacteria just hang around. The antibiotics knock them back enough to reduce symptoms, but as soon as conditions are right again, they go out of control. I was placed on 6 months of low dose macrobid, and had my last UTI in 2010. At least, my last until 2017. Long way of saying that I have a history of bacteria hanging on through antibiotics that should have cleared them. And bacteria that were asymptomatic until something triggered their uprising. Now I can’t help wondering if ‘pregnancy’ is what’s triggered uterine bacteria.

So, we must clear up the infection issue before we can make a decision to try again.

My cervix is the second issue. I think the TAC with Dr. Haney will address that. It comes at a high risk and a high physical cost, but it’s as good of an option as exists. Honestly, I’m grateful that there IS an option that works so well to solve one of my issues, even if the associated risks are great.

Overall, more answers, one potential solution, more risk and fear.

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