Subclinical hypothyroidism and anti-thyroid autoantibodies in women with subfertility or recurrent pregnancy loss SIP 2022

Question 1

Wordlide what is the most common reason for hypothyroidism?

Answer 1

Iodine deficiency

Question 2

Autoimmune hypothyroidism is cause by which thyroid specific antibodies?

Answer 2

TPO-Ab - against thyroid peroxidase, enzyme for thyroid hormone synthesis

Tg-Ab - against thyroglobulin, backbone against which thyroid hormones are synthesised

TRA-Ab - TSH receptor antibody

Question 3

Recommend iron intake during pregnancy and lactation?

Answer 3

Iodine 250ug daily

Question 4

What proportion of euthyroid women with anti-TPO develop thyroid abnormality?

Answer 4

10%

Question 5

TSH levels should be below what level in pre-conception period?

Answer 5

<2.5 (previously accepted 4-5)
Especially if Hx of sub fertility or recurrently pregnancy loss

Question 6

According to paper TSH levels upper normal, mild to moderate SCH and OH

Answer 6

Upper normal 2.5-4.0
Mild/moderate SCH 5-10
OH >20

Question 7

What is the prevalence of TPOan in women of child paring age?

Answer 7

5-20%
Higher in subfertilty/RPL 33%

Question 8

Impact of raised TSH on fertility?

Answer 8

Higher TSH - predict of fertilisation failure in women undergoing IVF

Women with sub fertility have slightly higher TSH

Question 9

Does high TSH impact rates of miscarriage?

Answer 9

Higher rates 6% >5 vs 3.6 < 2.5

Question 10

Effect of TPOAb on fertility

Answer 10

Female factor infertility more likely to have TPO-Ab
Link with PCOS
Higher rates of miscarriage

Question 11

Why is levothyroxine (LT4) offered to women undergoing IVF/ICSI with increased TSH and TPOAb?

Answer 11

As ovarian stimulation increases TSH levels

Question 12

Is there evidence for treating LT4 for women with raised SCH?

Answer 12

There is low-quality evidence that LT4 treatment in women with mild–moderate SCH (defined as TSH > 4.0 mIU/l) is associated with an improvement in pregnancy and miscarriage rates.

Offered in recurrent miscarriage.

Question 13

If SCH and TPOAb?

Answer 13

Lower clinical threshold for commencing LT4

Question 14

How to manage levothyroxine once patint pregnant?

Answer 14

Once pregnancy confirmed, increase dose on 2 days a week (Sat/Sunday to mini 20-30% increase in thyroid depend.
Check TSH at 7-9 weeks

Question 15

What is the starting dose of mild-moderate SCH

Answer 15

The starting dose of LT4 for women with untreated mild–moderate SCH is 1.0–1.2 μg/kg bodyweight per day.

Question 16

If SCH not on treatment, when should TFTs

Answer 16

be measured by 7-9 weeks

Question 17

If TPOAb +ve in pregnancy

Answer 17

Take TSH as soon as possible by 7-9 weeks