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Her menstrual, obstetrics, gynecological, medical, surgical, and drug history also should be described here to make things more clear. Her MRI or ultrasound report would be helpful for me to explain better.
Zoladex is Goserelin acetate, that is, luteinizing hormone releasing hormone agonist reduces sex hormone production and used in prostate cancer, treatment of endometriosis, and breast cancer. It has side effects like hot flushes, impotence, mood changes, sleep disorder, vaginal dryness.etc.
Normally, endometriosis symptoms should be better during pregnancy and in menopause. Injection Zoladex, I think not at all to be given in case of pregnancy as it is for sex hormones suppression. It can disturb pregnancy hormones as well and could be harmful in normal fetal development. Normally, if an infertile patient with endometriosis (mild to moderate) gets pregnant, her treatment stops and then whole concentration diverts to her pregnancy and its better management. But here, I really do not know which stage of endometriosis it is. You described till pancreas. Is this involved lymph nodes or having cancer effect? These are the most important questions in which further plan is based.
If this endometriosis is not having any cancer signs and with effects of pregnancy it would get better and having pregnancy would be a blessing and will cure symptoms, then obviously all efforts would be for safe pregnancy and it management must in future.
In case of cancerous element and if there is urgent need for chemotherapy or need to treat lymph nodes and other organs as you said involving pancreas then to have really clear and detailed look as either pregnancy would be in danger in that circumstances and could end up in miscarriage or could have harmful effect by disease inside patient's body and its treatment.
So, endometriosis stage and pregnancy status should be clearly defined for further treatment. As in last stage of endometriosis (cancerous) stage, we need to treat the patient more intensely and could have an effect on pregnancy. But in earlier stages with no cancer element, it will regress endometriosis and would not need treatment for it, only to manage pregnancy would be the best option.
I suggest Folic acid 0.4 mg daily now. And treat anemia if she can tolerate ferrous sulfate for iron deficiency.
Do have a transvaginal scan and serum beta hCG two times with an interval of 48 hours to have a clear view of pregnancy either doing well or unhealthy pregnancy. (serum beta hCG should increase more than 66 % in 48 hours in case of healthy pregnancy. If it increases but suboptimal could have chances of ectopic or miscarriage).
In case of failing pregnancy, God knows. It depends on how the body responds. If bleeds and expels itself or otherwise might need surgical or medical induced miscarriage.
In case of healthy early pregnancy, she will need lots of precautions and complete treatment of her other issues like anemia and electrolytes as you mentioned.
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