This is just a really quick note on a topic that is confusing for a lot of women: funneling. Many of us hear the word “funneling” and start to panic, but it’s a word that has some very different meanings.
What we women with cervical insufficiency need to worry about is funneling of the cervix, which often precedes premature dilation. You can funnel from the top down, or from the bottom up. With a TAC, it is possible to have a narrow funnel through the TAC (narrow because you should only be able to dilate up to about one centimeter with a properly placed TAC), but not common. It also doesn’t necessarily mean that your TAC will fail or that anything will happen to your baby; it’s just something that your doctor will have to keep an eye on.
A lot of times, you might hear a woman say that she “funneled to the TAC,” but not below. This is something that some doctors or ultrasound techs say, but it’s confusing. There is NO cervix above a TAC, just uterus. When a doctor tells a woman that she has funneled to her TAC, it’s a terminology problem, not an anatomy problem. It simply means that the lower uterine segment is beginning to expand, which always happens as the baby gains weight, and is a normal part of any pregnancy.* By itself, it is NOT a concern in a TAC pregnancy or any other pregnancy, although it’s possible that it might happen earlier in a woman with cervical insufficiency (I don’t know, and I’m not a doctor, that’s just a guess). Sometimes doctors say that means that you really did need a TAC, which I feel adds to the confusion, as the expansion of the lower uterine segment is only an indication that the baby is growing.
So if you hear that you, or any woman, has funneled “to the TAC,” know that it’s normal and probably not something to worry about. We have plenty to worry about already. Your doctor should be on the lookout for funneling through or below the TAC, which certainly can indicate a potential problem.
*This is also the reason that c-sections done before mid-late second trimester usually require a classical vertical incision. The lower uterine segment has not expanded enough for a low-transverse incision between the uterine arteries.