Thyroid Dysfunction And Reproductive Health

Question 1

What is the most common endocrine condition affecting women of reproductive age?

Answer 1

Thyroid dysfunction

Question 2

What is recommended about thyroid measurements in subfertile women?

Answer 2

No routine measurements in asymptomatic patients

Question 3

What is the rate of hyperthyroidism in subfertile women compared with general population?

Answer 3

2.3 % compared with 1.5 % in general population

Question 4

What menstrual irregularity associated with hyperthyroidism?

Answer 4

Hypomenorrhoea
Polymenorrhoea
+ sensitivity to Gnrh 》+ Lh 》 + SHBG 》 + total estrogens

Question 5

What is the rate of anovulatation in women with hyperthyroidism ?

Answer 5

Most women remain ovulatory.
And there is no evidence that treatment of either subclinical or clinical hyperthyroidism improves the rate of ovulation

Question 6

What is the impact of radioactive iodine on fertility?

Answer 6

No deterioration in gonadal function
Or adverse outcomes in offspring

Question 7

What is the period of time the pregnancy is delayed after treatment with radioactive iodine?

Answer 7

6 months

Question 8

What drug causes hypothyroidism?

Answer 8

Amiodaron / lithium

Question 9

What is the prevalence of hypothyroidism and subclinical hypothyroidism in women in reproductive age?

Answer 9

0.5 %
Subclinical: 2 - 4 %

Question 10

How does hypothyroidism affect fertility?

Answer 10

It affects the pulsatile release of GnRH which is required for cyclical release of fsh Lh

Question 11

What TSH level is required in women undergoing ART?

Answer 11

< 2.5 mu/ml

Question 12

The impact of treatment with levothyroxine( in women with overt or subclinical hypothyroidism) on implantation and pregnancy and live birth rates?

Answer 12

Improves the rates . But still reduced compared with euthyroid

Question 13

Recommendations about TSH levels in sub fertility setting ?

Answer 13

Keep tsh below 2.5 mu/ml per conception in line with guidelines for first trimester tsh levels

Question 14

What is the most common cause for hypothyroidism in women of reproductive age?

Answer 14

Autoimmune thyroid disease
AITD

Question 15

Thyroid autoantibodies are present in what rate in :
Hashimoto’s thyroiditis
Postpartum thyroiditis
Graves disease

Answer 15

All
2/3
3/4
Respectively

Question 16

What is the prevalence of thyroid autoimmunity among general population?

Answer 16

Up to 25%
And higher in those with endometriosis and pco
And subfertile group

Question 17

Management of thyroid diseases in the fertility setting if Tsh 2.5 - 4.5 ?

Answer 17

1 - repeat Tsh
2- test thyroid autoantibodies
If tsh still > 2.5 commence thyroxin.
And test tsh every 6 weeks until < 2.5
If +ve antibodies in case of pregnancy results : monitor TFT
Fetal growth

Question 18

Management of thyroid diseases in fertility setting if TSH > 4.5 ?

Answer 18

1- commence levothyroxine
2- check T3 T4 autoantibodies

Question 19

What are the physiological changes of pregnancy in thyroid functions ?

Answer 19

• 1- increased thyroid binding globulin due to estrogen stimulation
  2- increased clearance if free thyroid hormones due to increased glomerular filtration
  Result in : reduction in free thyroid hormones
• bhcg is closely related structurally to Tsh which stimulates thyroid hormones release and suppresses Tsh in first trimester
• in 2nd and 3d trimester Bhcg levels fall accompanied by rise in tsh

Question 20

What is the miscarriage rate in women euthyroid and positive for thyroid autoantibodies ?

Answer 20

Three fold increase

Question 21

What is the most common cause for hyperthyroidism in pregnancy?

Answer 21

Graves disease affecting 1 % of pregnancies

Question 22

What is the cause of gestational hypothyroidism? Prevalence?

Answer 22

Stimulation of Tsh receptors by B hcg
Affecting 1-3% of pregnancies

Question 23

How to distinguish between graves disease and gestational hyperthyroidism?

Answer 23

TSH stimulating receptors antibodies is diagnostic of graves disease TSI

Question 24

Management of gestational hyperthyroidism?

Answer 24

Supportive management
(Free T4 tends to return to normal in 2nd trimester )
Thyroid replacement is not required

Question 25

Management of Graves disease in pregnancy?

Answer 25

Propylthiouracil is preferred ( because of lower levels of teratogenicity Carbimazol : in 2nd trimester ( concerns over propylthiouracil hepatotoxicity in offspring)

Question 26

What are the risks of Graves disease in pregnancy?

Answer 26

Preterm birth Pre eclampsia FGR Heart failure Still birth

Question 27

What is the particular risk in the infants of hypothyroidism mothers?

Answer 27

Neurodevelopmental delay (Because of the fetal requirements for maternal T4 until 12 weeks of gestation ) after that T3 T4 Tsh don't cross the placenta

Question 28

What are the neonatal complications of hypothyroidism in pregnancy?

Answer 28

1- neurodevelopmental delay 2- neonatal hypothyroidism ( trans placental transfer of Tsh receptors blocking antibodies)(mainly seen in atrophic thyroiditis) 3- prematurity/ low birth weight 4- fetal distress in labour 5- stillbirth 6- perinatal death 7- congenial malformations

Question 29

What are the maternal complications of hypothyroidism in pregnancy?

Answer 29

1- anaemia 2- postpartum hemorrhage 3- cardiac failure 4- pre eclampsia 5- placental abruption

Question 30

What is the major risk in women euthyroid with AITD in pregnancy?

Answer 30

Preterm birth 2 to 4 folds Increased risk (Eventhough treatment with thyroxin is not recommended )

Question 31

What are the risk factors of thyroid dysfunction which indicates screening ?

Answer 31

1 History of thyroid dysfunction/surgery 2 Family history of thyroid dysfunction 3 Goitre 4 Clinical signs of hypothyroidism 5 + ve thyroid autoantibodies 6 Diabetes type 1 7 Other autoimmune disorders 8 History of miscarriage/preterm 9 History of subfertility 10 Age > 30 11 History of head/ neck irradiation 12 Previous treatment of amiodaron/lithium 13Recent exposure to iodine radiological agents

Question 32

How to adjust L T4 dose in pregnancy?

Answer 32

Initially 25 mcg / daily Tsh every 4- 6 weeks Further increase may required to maintain the Tsh 0.5- 2.5

Question 33

Trimester specific Tsh ranges ?

Answer 33

1st : 0.1 - 2.5 2nd : 0.2 - 3 3d: 0.3 - 3

Question 34

How often Tsh would be tested in women euthyroid with AITD In pregnancy?

Answer 34

Every 4 weeks in early pregnancy And at least once between 26-32 weeks

Question 35

When to check Tsh postpartum in hypothyroidism women?

Answer 35

6-8 weeks postpartum

Question 36

Is there any recommendations about euthyroid + AITD and treatment with LT4?

Answer 36

No recommendations of treatment both preconception or during pregnancy