Cyst in umbilical cord, any idea?

[Mangosteen]

Dear everyone:

I am now 22 weeks. During the ultrasound scan in 20 week, everything is OK except a cyst is detected in the umbilical cord very near the cord insertion of the baby. I am worrying about it. Then in week 21week+4d, I did another follow-up scan for the cyst and found the cyst is a little bit bigger (for a 10-day period). Then the doctor recommends amniocentesis to eliminate the chromosome-related defects (it is reported that there is chance the cyst in umbilical cord may be associated with certain fetal malformation, or may not). Immediately I had the amniocentesis test. The preliminary report for chromosomes 13, 18 and 21 is available and everything is normal. Now I am waiting for the full report for all chromosomes, due in 2 weeks.

I am in Singapore, and the scans here are 2-dimensional (2-D), including the detailed scan at 20 week for malformation checking.

So I want to ask:

First, are the routine scans you did in your country 2-D or 3-D? And how about the detailed scan at 20 week, 2-D or 3-D? I searched online and find it seems the 3-D scan (even 4-D, with the last dimension being time, in addition to the 3 dimensions of space) is more accurate…… so I am wondering whether I should do a 3-D detail scan to eliminate any malformation.

Second, if all the chromosomes are normal from the amniocentesis, what else can I do to further eliminate the fetal malformation? Any advanced tests? Any suggestions?

Third, we want to do a DNA blood test to further confirm the results of amniocentesis. Does it make sense? (I have searched and found that the DNA test has comparable accuracy as amniocentesis, but does not require a penetration).

Thank you all in advance!