REPOST: Dr. Ain: && Re: ThyCa and pregnancy -->

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(Dr.Ain)

Date: Fri, 02 Jun 2000 16:10:53 -0400

Subject: Answers to questions

yCa Members:

This is in response to the questions below concerning I-131, hypothyroidism, and

family planning:

1. Fetal brain development appears susceptible to maternal hypothyroidism.

This is most critical during the first 8-9 weeks of fetal development, before

the fetal thyroid becomes functional. For that reason, one should not plan to

conceive a pregnancy until the mother's TSH is at least at or below the normal

range. In addition, therapeutic dose of I-131 may cause a temporary menstrual

irregularity which normalizes within 6 months. For these reasons, I typically

suggest that female patients who are planning a pregnancy wait at least 6 months

from their last I-131 therapy dose or 2 months from their last negative

hypothyroid I-131 scan, before discontinuing birth control.

2. In regards to the concept of tumor stunning, the following statements have

been sent by me before:

In this situation, the small I-131 dose used for the scan can " stun " the tumor

so that the therapy dose

is ineffective by not being taken up. If I suspect or detect this phenomenon,

it is my practice to put the patient back on levothyroxine for six months & then

perform a hypothyroid/low iodine diet preparation for a therapeutic radioiodine

dose (the size based on sites of metastasis) without a preceding scan. Prior to

discharge, I perform a post-therapy scan (which uses the previously-administered

therapy dose as the scanning dose). This approach has been generally successful

in our hands.

**************PLEASE BE ADVISED**********************

THE INFORMATION CONTAINED IN THIS COMMUNICATION IS INTENDED

FOR EDUCATIONAL PURPOSES ONLY. IT IS NOT INTENDED, NOR SHOULD

IT BE CONSTRUED, AS SPECIFIC MEDICAL ADVICE OR DIRECTIONS. ANY

PERSON VIEWING THIS INFORMATION IS ADVISED TO CONSULT THEIR OWN

PHYSICIAN(S) ABOUT ANY MATTER REGARDING THEIR MEDICAL CARE.

*************************************************

B. Ain, M.D.

Associate Professor of Internal Medicine

Director, Thyroid Nodule & Oncology Clinical Service

Director, Thyroid Cancer Research Laboratory

Division of Endocrinology and Molecular Medicine

Department of Internal Medicine, Room MN524

University of Kentucky Medical Center

800 Rose Street, Lexington, Kentucky 40536-0298

>you are probably getting I-123 instead of I-131

>for the scan. I-123 has a much shorter half life than I-131 (something

>like 13 hours compared to 8 days I believe)

I'm confused now. Why would I-131 given for a scan interfere with the

absorption of I-131 given for a RAI -- which in my case was given within

hours of the scan? Are I-123 scans just as effective?

I am particularly interested in this question because I am due for a scan

in Sept, shortly after my 38th birthday. Because of my age, my husband and

I were hoping to have another child as soon as possible. Because my pap ca

was caught early, we even considered postponing a follow-up scan until

after a child, but decided that that would be losing the advantage of

having caught it early.

I can't seem to get a consistent answer re: how soon after a clean scan it

would be OK to try and get pregnant. One doc says 6 weeks -- since

diagnostic dose is small, as long as we check that i131 is gone from my

system. Another says that the diagnostic dose is still significant and also

it takes a long time to get thyroid hormone normal again. So he says 6

months. OB says he knows little about these treatments, but that the sooner

the better at my age in terms of fertility, and history of early

miscarriages. What is the right amount of time/things to wait for? Would

that change if we had an I123 scan instead of I131?

Also, I have read of concerns that the mother being hypo is bad for the

fetal brain development -- is there a critical window for this?

My PCP, who started as an endo years and years ago, currently manages my T4

dosage and I am very happy with his responsiveness. But I do not feel

comfortable that he knows as much about the issues relating to managing T4

before/during pregnancy, so I want to go to someone who is an endo for that

period. Should I look for an endo specializing in fertility (eg recommended

by my OB), or one specializing in ThyCa (eg recommended by Nuclear

Medicine)? Here where I live, Nuclear Medicine manages ThyCa long term, not

endos, which is why I don't already have an Endo.

Well, that is a lot of questions. Hope you are not now totally confused

too. I would be very interested in hearing from other women who have

balanced childbearing with ongoing RAI monitoring.

Thanks,

Kate

diag papca 12/99, tt 1/00, RAI 150mc 3/00

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Date: Mon, 09 Aug 1999 09:52:34 -0400

Subject: Re: RAI/Breastfeeding

>Hello All,

>

>I had heard that its taboo to have RAI while a woman is still

>lactating/breastfeeding. Anyone familiar with this? Wife, Beth is getting a

>200 dose in late Sept. and is still breastfeeding our little guy.

>

>Thanks

>

>

>Albany, NY

>wife pap thyca -- tt 6/99 3.5 cm " unencapsulated " with two lymph glands

>yanked at no extra charge.

To " " and ThyCa members:

It is critically important to totally terminate breast feeding prior

to any radioactive iodine scanning or treatment dose. The radiokinetics of

radioactive iodine would not permit breastfeeding for at least 60 days in

order to avoid destroying the baby's thyroid gland or causing thyroid

cancer in the baby. There is no sense to continue lactation, discarding

the milk, and resuming more than 2 months later since the baby would

already be weaned from breast feeding. This is not just a recommendation.

It is a necessity. I do not believe that any nuclear medicine facility

would knowingly administer any radioactive iodine to any woman who is

intending to continue breast feeding. This does not apply to later

pregnancies, provided that there is no need for further scanning and

therapy. As a practical guideline, women thyroid cancer patients should

tend to avoid breastfeeding their children if there is any reasonable

chance that they would need to receive radiopharmaceuticals at anytime

while breastfeeding.

**************PLEASE BE ADVISED**********************

THE INFORMATION CONTAINED IN THIS COMMUNICATION IS INTENDED

FOR EDUCATIONAL PURPOSES ONLY. IT IS NOT INTENDED, NOR SHOULD

IT BE CONSTRUED, AS SPECIFIC MEDICAL ADVICE OR DIRECTIONS. ANY

PERSON VIEWING THIS INFORMATION IS ADVISED TO CONSULT THEIR OWN

PHYSICIAN(S) ABOUT ANY MATTER REGARDING THEIR MEDICAL CARE.

*************************************************

B. Ain, M.D.

Associate Professor of Internal Medicine

Director, Thyroid Nodule & Oncology Clinical Service

Director, Thyroid Cancer Research Laboratory

Division of Endocrinology and Molecular Medicine

Department of Internal Medicine, Room MN520

University of Kentucky Medical Center

800 Rose Street, Lexington, Kentucky 40536-0084

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________________________________________________________________________________\

________________________________

>Date: Sat, 01 Sep 2001 12:02:35 -0400

>

>

> >Hi All, I am working with a thycan who has been told that she might

> >not be able to conceive because of thyca. I don't think this is

> >correct as I have had 3 more children since thyca ( I was preg with

> >first when thyca was found) I am looking for Dr. posts concerning

> >this.

>

>

>

> From Mother Risk Program - Hospital for Sick Children - Toronto

>

>Thyroid Cancer and Pregnancy

>http://www.motherisk.org/cancer/thyroid.php3

>

>

>Fertility does not appear to be affected by thyroid cancer.

>Furthermore, a follow-up study of seventy female patients treated with

>high doses of iodine-131 for differentiated thyroid cancer who underwent

>a subsequent pregnancy failed to detect a significantly increased rate

>of birth defects or adverse fetal outcomes provided patients avoid

>pregnancy for a period necessary to ensure total elimination of the

>radionuclide.

>

>

>There is more info with medical references at the site.

>

>

>dx pap Hurthle cell variant, tt 9/99, RAI 100 mCi 12/99

>

________________________________________________________________________________\

_____________________________________

>Date: Fri, 22 Jun 2001 07:54:13 -0400 (EDT)

>From: Kassiryn@...

>Subject: Re: First Post from a Newcomer

> > Second question (for the women)- has anyone had children after

> > surgery and RAI treatments? If so, were there particular

> > issues/problems with conception/pregnancy?

> >

>

>I haven't had a baby since thyca, but I was postpartum with a breastfeeding 2

>month old when diagnosed, so I had a lot of research to do.

>

>What I think you'd find as your challenges are:

>1) timing. You have to wait 6-12 months after RAI before conceiving. In my

>research, I found that women who pumped breastmilk and then had it

>geigercountered wound up having to pump and dump approx. 80 days (or 10

>half-lives of iodine). So, the RAI does stay in your system quite awhile,

>hence the precaution to wait 6-12 months (and given that it is radiation, I'd

>lean on the conservative side). In addition, standard protocol calls for at

>least 1 clean scan 6-12 months post treatment, and hence more radiation.

>Thus, it's going to take awhile before you can fit a pregnancy in.

>2) once you are clear to have a baby, if you plan on trying, you need to have

>your TSH monitored very carefully, and during the first few weeks of pregancy

>get it tested because pregnancy can change how much T4 you need. It's

>important for the developing fetus that you not be hypo.

>3) having a tt can affect your menstrual cycle. Not necessarily your

>fertility, but if you had a typical pattern before your tt, you can't assume

>you'll have the same pattern post-tt. It's one of those YMMV things but your

>thyroid plays a big factor in regulating all that.

>4) based on my experience (I have 7 children), having thyca is likely to put

>you in a 'high-risk' pregnancy category. Obsetricians characterize your

>pregnacy based on things like age, number of pregnancies and major health

>issues. Since thyca gets rid of your thyroid, that makes it a major health

>issue. However, by high-risk and given no other complications, they probably

>will just want extra tests along the way to monitor the baby's health.

>5) the only other issue to factor into any decision is that there is some

>antecdotal evidence that pregnancy can cause thyca to grow. Obviously,

>they've never studied it (how could they?) While 90% of thyroid nodules are

>benign, the figure drops for those discovered during a pregnancy. In my case,

>I didn't have a lump in my thyroid in late Feb. '00 at 6 months pregnant,

>and did have one at the beginning of June that was discovered at a postpartum

>checkup. Anyway, my endo said that there is some antecdotal evidence of a

>correlation. If you get all through with clean scans, that probably wouldn't

>be a big factor, but just a FWIW.

>

>HTH,

>Kathy

>pap

>tt 7/00 RAI 8/00

>2nd week of hypo (still surviving) waiting for a scan in July

>

________________________________________________________________________________\

_______________________________________

At 12/27/01 09:54 PM, you wrote:

>Hi everyone

>

>Just a question. My husband and I are considering having another child. Does

anyone out there have any suggestions on where to research pregnancy after ThyCa

and RAI? I've talked to my doctor and she said there is no reason not to get

pregnant. She said the only thing to take in consideration is the increased

need for thyroid hormone during pregnancy and the need for my levels to be

closely monitored by her. I know you should wait 6 months to one year after RAI

to get pregnant. My biggest questions are is pregnancy going to increase my

chance for a reoccurrence, will my baby be harmed in any way from synthroid, can

I breast feed safely while on synthroid, and what are the odds of my child

getting ThyCa?

>

>Thank you for any input