Understanding Shortened Cervix and Funneling During Pregnancy

Question
Hi Brenda, hope you can help. A little background. I'm 36 y.o.  with my fourth pregnancy. I have one healthy 3 y.o. daughter born at term via c-section for frank breech. Uncomplicated pregnancy. She was born with pulmonary stenosis, was in NICU for 8 days on PGE and then had an angioplasty at one month of age. Very healthy now. I then had 2 miscarriages, one was a spontaneous loss at 10weeks (saw heartbeat at 9 weeks) and the second was a missed miscarriage at 10 weeks  due to trisomy 21. I had a d/c for this loss. A year later we are pregnant again. I have been watched closely by my obgyn. I saw a perinatologist for a fetal echo at 21 weeks, my babygirl seems very healthy but they did  note that my cervical length  was 2cm and funneling. My previous u/s (transvaginal as well) was at 20weeks with my obgyn and my cervix was 4.4cm and closed. My peri stated that there was no indication for treatment or bedrest at this time. She stated that this was more than likely not a new finding. I could continue working full time (ICU RN, working 12 hour shifts). She stated that because my daughter was full term it would be highly unlikely to have this baby preterm. She stated a d/c would not put me at risk for an IC. She also stated that the previous u/s findings were probably reader error (I've had about 8 transvaginal u/s none of which showed any previous changes. My question is should I be taking any precautions? Are there any questions I should be asking? Any  tests I should be requesting? I was under the impression that I would be a candidate for a cerclage? Are my measurements acceptable for a wait and see approach? Is there a time limit for a cerclage ? Are there any other alternatives? I'm currently 23 weeks pregnant and have felt a lot of menstrual cramping with decreased fetal movement... the oncall doc checked my cervix with a speculum and says everything is fine and closed. "Try not to worry" seems to be their mantra. I know that I've written a book and I certainly don't expect you to negate what my physician has told me, I recognize that this would be information not advice however I would hope that from your previous experiences you might be able to give me a general feel for what I should be doing or should be expecting or even perhaps requesting? As any pregnant mother I do not want to lose my baby.  Thanks for reading my long winded question. Monica

Answer
Dear Monica,

OK - I'm getting the impression your main concern here is the possibility of an IC, so I'll address that first.

The causes of an incompetent cervix can range from trauma to the cervix including extensive cervical conization (cervical biopsy), uterine abnormalities and anomalies, and undergoing a forced D & C with a late pregnancy termination. Even previous childbirth can weaken the cervix. For some women, there is no definitive cause for an incompetent cervix. When the cervical opening is greater than 2.5 cm, or the cervical length has shortened to less than 2 cm, a diagnosis can be made for IC. Also, funneling of the cervix can be a sign that the cervix has begun to efface.

The main symptom or complaint with IC is increased discharge and feeling some heaviness in the pelvis. However, this complaint is usually not felt until a dilated cervix is feeling the pressure of the bag of waters. Tragically, many cases are not detected until premature rupture of membranes/delivery occurs.

Once IC is diagnosed, cerclage would be the treatment. However, most often this is done at 12-15 weeks. The risks of premature labor, premature rupture of membranes, and possible cervical tearing due to the pressure may possibly be increased in the 3rd trimester.

It's encouraging that your cervix is closed at this point. The funneling may just be a sign that you are starting to soften/efface a bit, but if your cervix is remaining closed and the length is still 2cm, I would be comfortable with your OB watching closely.

You really just need to pay attention to your body. If you are having more discomfort/cramping after working a 12 hour shift at this point in your pregnancy, it may be time to start looking at cutting down to 8's (if possible) or cutting shifts. I know you know all this as well as I do - get your feet up as much as possible, drink good fluids, eat regular, healthy meals, and so on.... If you feel unusual symptoms that concern you (significant/continued decrease in fetal movement, pelvic pressure, and spotting or discharge, etc,..), call your doctor (just like you've done with the on call doc).

As far as additional questions or tests - it sounds like you've covered everything that you need to. You've had the TV U/S(s) and your doc is aware of the change in the cervix at this point. If you feel like you'd be more comfortable starting 2 week visits now (if they aren't going to start that anyway), ask about that. It may be that it can be covered as medically necessary with the funneling and shortening of the cervix.

I hope that covered most of your questions. :-)  At this point, though I know it's difficult for you, nothing jumps out at me that makes me disagree with waiting and watching closely.

Brenda