Dear Friend,
I empathize you for the different problems you are facing. Let us discuss them one by one.
One arm of CuT remaining in the cervical wall should not cause you any problem. Later the
cervix gets softened and during labourit gets merged with the uterus. During delivery also it should not cause any problem. There is a slight possibility that it may be expelled out during labour.
Your
pregnancy is no concern for me. It is growing nicely as revealed by
ultrasonography.
The main issue is that of blood cyst in the ovary. It could be, as your doctors have in mind, another baby growing in the ovary (ectopic pregnancy). Since it is drawing a good amount of blood supply, this differential diagnosis has to be kept in mind. Such babies usually do not grow much and have to removed by opening the abdomen. There is chance that it may get expelled in the abdomen and then grow in the abdomen. However, these babies do not live outside even if they complete 9 months. Hence, after confirmation, removal of such ectopic pregnancy is always an option of choice.
Your history suggests that your one ovary was already removed for huge
dermoid cyst during your childhood. On the other side also you had some cyst for which major part of left ovary was removed. I am really surprised to note that with a small ovarian tissue remaining, you have conceived. So it is likely that the remaining ovary is not just 1/8th, could be larger. The recurrence of cyst cannot be ruled out. However, benign dermoid cyst should not have blood in it.
I feel, monitoring of this blood containing so called cyst / ectopic pregnancy is necessary. If the cyst is confirmed to be a pregnancy, then removal is not only indicated, but is mandatory to prevent further serious complications. May be in this procedure you could loose the remaining of or some of your ovarian tissue. However, to save your life, sacrificing the ovary / ovarian tissue should be acceptable.
If it turns out to be
ovarian cyst, depending up on the type of the cyst (benign or malignant), its size and other aspects, the doctors will decide whether the remaining ovary can be left or has to be removed. If it is a cyst, then the ovary has shown tendency of recurrence, my dear. So better the ovary is out if it comes to that.
By removal of the ovary, you would attain the
menopause at an early age; however, it can be managed by
hormonal replacement for some time till you stabilize with the menopause.
I hope I have clarified all the issues you have raised in your query.
Now monitor the cyst in the ovary, accept the treatment for it and wait patiently for the delivery of this child with a cherish. Wish you the best of the motherhood.