Prenatal testing after cervical surgeries

Prenatal testing, like CVS, may be complicated after having a LEEP or cone biopsy. The reason is the scarring will cause some stenosis, which makes the cervix tighter.

Currently, there are two prenatal testing options: CVS and amniocentesis. Let's talk first about what CVS is. It stands for chorionic villus sampling, and it's a procedure where a flexible tube is pushed through the cervix (going up through the vagina). A small piece of tissue is taken from the developing baby and placenta, and the tissue is sent off to the lab to examine it for some genetic problems, like cystic fibrosis or fragile X syndrome.

Chorionic villi look like little fingers under the microscope, and the chorionic villus is the tissue that becomes both the baby and the placenta. So the genes in both are the same, but because the tissue is not specifically from the baby, they can't tell if the baby has neural tube defects. Only amniocentesis can tell you that.

CVS is done usually between 10-12 weeks of pregnancy, and some families like the idea of testing early and also not having a needle go through the mother's abdomen. But the problem for some women post-cervical surgery is that the cervix may not cooperate for the procedure.

If your cervix is really tight because of cervical stenosis, it may be too difficult to get the tube through, and the doctor doesn't want to force it too hard and hurt the baby on the other side. If you have scarring that kinks the cervix, it may also be difficult for the doctor to get the tube through. My perinatologist, who was a very experienced doctor, would have attempted it if I had really wanted it, but he was hesitant. So when I said I would wait for amniocentesis, he quickly agreed that that was safer for me.


The leads me to amniocentesis, another prenatal testing option. I had it done at 16 weeks. If you want to know for sure that your baby doesn't have certain genetic defects, like neural tube defects, then get amniocentesis. The risk of losing the baby is very low, and it is not painful.

The data about miscarriage after amniocentesis is very old--from the days before doctors used ultrasound to watch where the needle goes. Back then, it was more risky because they just stuck the needle in, and sometimes they hit the baby.  The risk then was 1/200 as a result of that blind needle placement.  Today, they watch on ultrasound, and both you and the doctor can clearly see where that needle goes. The needle is nowhere near the baby.

Today, the top perinatologists really think that the risk of miscarriage is more like one out of 10,000 rather than 1/200.

When the needle goes into your uterus, your uterus will cramp because it is a muscle. How painful that is depends on how bad you think cramps are. I thought it was uncomfortable, but not outright painful, and it was really quick. The needle was in for less than 2 minutes. 

The doctor very slowly inserts a 2 inch needle through your abdomen and into your uterus. Surprisingly, I didn't think that the needle stick hurt. Once the needle is in the uterus, the doctor draws out a small amount of amniotic fluid, and then it's over. You can get a quick result in a few days, and the full results take about a week.

You can ask your doctor about taking some ibuprofen before the procedure to lessen the cramps. I am telling you, though, it's really quick, and it's not so scary.

Because the amniocentesis needle goes through your belly, it doesn't matter that you had surgery on your cervix in the past.  Your risk of miscarriage from amniocentesis is the same as any other woman.    

Prenatal testing is possible after cervical surgeries, but you may have to wait for amniocentesis. Talk to the perinatologist about your options.